merge 3.4 (#23481)

197 files changed, 8221 insertions, 2583 deletions

diff --git a/Lib/test/_test_multiprocessing.py b/Lib/test/_test_multiprocessing.py
index 9466d4ebd6..d048f6feab 100644
--- a/Lib/test/_test_multiprocessing.py
+++ b/Lib/test/_test_multiprocessing.py
@@ -2551,7 +2551,7 @@ class _TestPicklingConnections(BaseTestCase):
 
         l = socket.socket()
         l.bind((test.support.HOST, 0))
-        l.listen(1)
+        l.listen()
         conn.send(l.getsockname())
         new_conn, addr = l.accept()
         conn.send(new_conn)
@@ -3198,7 +3198,7 @@ class TestWait(unittest.TestCase):
         from multiprocessing.connection import wait
         l = socket.socket()
         l.bind((test.support.HOST, 0))
-        l.listen(4)
+        l.listen()
         addr = l.getsockname()
         readers = []
         procs = []
diff --git a/Lib/test/datetimetester.py b/Lib/test/datetimetester.py
index f42b0f907c..7935cf2320 100644
--- a/Lib/test/datetimetester.py
+++ b/Lib/test/datetimetester.py
@@ -3,6 +3,7 @@
 See http://www.zope.org/Members/fdrake/DateTimeWiki/TestCases
 """
 
+import decimal
 import sys
 import pickle
 import random
@@ -50,6 +51,17 @@ class TestModule(unittest.TestCase):
         self.assertEqual(datetime.MINYEAR, 1)
         self.assertEqual(datetime.MAXYEAR, 9999)
 
+    def test_name_cleanup(self):
+        if '_Fast' not in str(self):
+            return
+        datetime = datetime_module
+        names = set(name for name in dir(datetime)
+                    if not name.startswith('__') and not name.endswith('__'))
+        allowed = set(['MAXYEAR', 'MINYEAR', 'date', 'datetime',
+                       'datetime_CAPI', 'time', 'timedelta', 'timezone',
+                       'tzinfo'])
+        self.assertEqual(names - allowed, set([]))
+
 #############################################################################
 # tzinfo tests
 
@@ -616,8 +628,12 @@ class TestTimeDelta(HarmlessMixedComparison, unittest.TestCase):
         # Single-field rounding.
         eq(td(milliseconds=0.4/1000), td(0))    # rounds to 0
         eq(td(milliseconds=-0.4/1000), td(0))    # rounds to 0
+        eq(td(milliseconds=0.5/1000), td(microseconds=0))
+        eq(td(milliseconds=-0.5/1000), td(microseconds=0))
         eq(td(milliseconds=0.6/1000), td(microseconds=1))
         eq(td(milliseconds=-0.6/1000), td(microseconds=-1))
+        eq(td(seconds=0.5/10**6), td(microseconds=0))
+        eq(td(seconds=-0.5/10**6), td(microseconds=0))
 
         # Rounding due to contributions from more than one field.
         us_per_hour = 3600e6
@@ -1131,11 +1147,13 @@ class TestDate(HarmlessMixedComparison, unittest.TestCase):
         #check that this standard extension works
         t.strftime("%f")
 
-
     def test_format(self):
         dt = self.theclass(2007, 9, 10)
         self.assertEqual(dt.__format__(''), str(dt))
 
+        with self.assertRaisesRegex(TypeError, '^must be str, not int$'):
+            dt.__format__(123)
+
         # check that a derived class's __str__() gets called
         class A(self.theclass):
             def __str__(self):
@@ -1287,8 +1305,6 @@ class TestDate(HarmlessMixedComparison, unittest.TestCase):
                 return isinstance(other, LargerThanAnything)
             def __eq__(self, other):
                 return isinstance(other, LargerThanAnything)
-            def __ne__(self, other):
-                return not isinstance(other, LargerThanAnything)
             def __gt__(self, other):
                 return not isinstance(other, LargerThanAnything)
             def __ge__(self, other):
@@ -1391,9 +1407,10 @@ class TestDate(HarmlessMixedComparison, unittest.TestCase):
         for month_byte in b'9', b'\0', b'\r', b'\xff':
             self.assertRaises(TypeError, self.theclass,
                                          base[:2] + month_byte + base[3:])
-        # Good bytes, but bad tzinfo:
-        self.assertRaises(TypeError, self.theclass,
-                          bytes([1] * len(base)), 'EST')
+        if issubclass(self.theclass, datetime):
+            # Good bytes, but bad tzinfo:
+            with self.assertRaisesRegex(TypeError, '^bad tzinfo state arg$'):
+                self.theclass(bytes([1] * len(base)), 'EST')
 
         for ord_byte in range(1, 13):
             # This shouldn't blow up because of the month byte alone.  If
@@ -1469,6 +1486,9 @@ class TestDateTime(TestDate):
         dt = self.theclass(2007, 9, 10, 4, 5, 1, 123)
         self.assertEqual(dt.__format__(''), str(dt))
 
+        with self.assertRaisesRegex(TypeError, '^must be str, not int$'):
+            dt.__format__(123)
+
         # check that a derived class's __str__() gets called
         class A(self.theclass):
             def __str__(self):
@@ -1790,6 +1810,7 @@ class TestDateTime(TestDate):
                           tzinfo=timezone(timedelta(hours=-5), 'EST'))
         self.assertEqual(t.timestamp(),
                          18000 + 3600 + 2*60 + 3 + 4*1e-6)
+
     def test_microsecond_rounding(self):
         for fts in [self.theclass.fromtimestamp,
                     self.theclass.utcfromtimestamp]:
@@ -1840,6 +1861,7 @@ class TestDateTime(TestDate):
         for insane in -1e200, 1e200:
             self.assertRaises(OverflowError, self.theclass.utcfromtimestamp,
                               insane)
+
     @unittest.skipIf(sys.platform == "win32", "Windows doesn't accept negative timestamps")
     def test_negative_float_fromtimestamp(self):
         # The result is tz-dependent; at least test that this doesn't
@@ -2219,6 +2241,9 @@ class TestTime(HarmlessMixedComparison, unittest.TestCase):
         t = self.theclass(1, 2, 3, 4)
         self.assertEqual(t.__format__(''), str(t))
 
+        with self.assertRaisesRegex(TypeError, '^must be str, not int$'):
+            t.__format__(123)
+
         # check that a derived class's __str__() gets called
         class A(self.theclass):
             def __str__(self):
@@ -2282,13 +2307,14 @@ class TestTime(HarmlessMixedComparison, unittest.TestCase):
             self.assertEqual(orig, derived)
 
     def test_bool(self):
+        # time is always True.
         cls = self.theclass
         self.assertTrue(cls(1))
         self.assertTrue(cls(0, 1))
         self.assertTrue(cls(0, 0, 1))
         self.assertTrue(cls(0, 0, 0, 1))
-        self.assertFalse(cls(0))
-        self.assertFalse(cls())
+        self.assertTrue(cls(0))
+        self.assertTrue(cls())
 
     def test_replace(self):
         cls = self.theclass
@@ -2347,6 +2373,9 @@ class TestTime(HarmlessMixedComparison, unittest.TestCase):
         for hour_byte in ' ', '9', chr(24), '\xff':
             self.assertRaises(TypeError, self.theclass,
                                          hour_byte + base[1:])
+        # Good bytes, but bad tzinfo:
+        with self.assertRaisesRegex(TypeError, '^bad tzinfo state arg$'):
+            self.theclass(bytes([1] * len(base)), 'EST')
 
 # A mixin for classes with a tzinfo= argument.  Subclasses must define
 # theclass as a class atribute, and theclass(1, 1, 1, tzinfo=whatever)
@@ -2606,7 +2635,7 @@ class TestTimeTZ(TestTime, TZInfoBase, unittest.TestCase):
         self.assertRaises(TypeError, t.strftime, "%Z")
 
         # Issue #6697:
-        if '_Fast' in str(type(self)):
+        if '_Fast' in str(self):
             Badtzname.tz = '\ud800'
             self.assertRaises(ValueError, t.strftime, "%Z")
 
@@ -2641,7 +2670,7 @@ class TestTimeTZ(TestTime, TZInfoBase, unittest.TestCase):
             self.assertEqual(derived.tzname(), 'cookie')
 
     def test_more_bool(self):
-        # Test cases with non-None tzinfo.
+        # time is always True.
         cls = self.theclass
 
         t = cls(0, tzinfo=FixedOffset(-300, ""))
@@ -2651,23 +2680,11 @@ class TestTimeTZ(TestTime, TZInfoBase, unittest.TestCase):
         self.assertTrue(t)
 
         t = cls(5, tzinfo=FixedOffset(300, ""))
-        self.assertFalse(t)
+        self.assertTrue(t)
 
         t = cls(23, 59, tzinfo=FixedOffset(23*60 + 59, ""))
-        self.assertFalse(t)
-
-        # Mostly ensuring this doesn't overflow internally.
-        t = cls(0, tzinfo=FixedOffset(23*60 + 59, ""))
         self.assertTrue(t)
 
-        # But this should yield a value error -- the utcoffset is bogus.
-        t = cls(0, tzinfo=FixedOffset(24*60, ""))
-        self.assertRaises(ValueError, lambda: bool(t))
-
-        # Likewise.
-        t = cls(0, tzinfo=FixedOffset(-24*60, ""))
-        self.assertRaises(ValueError, lambda: bool(t))
-
     def test_replace(self):
         cls = self.theclass
         z100 = FixedOffset(100, "+100")
@@ -3780,6 +3797,60 @@ class Oddballs(unittest.TestCase):
         self.assertEqual(as_datetime, datetime_sc)
         self.assertEqual(datetime_sc, as_datetime)
 
+    def test_extra_attributes(self):
+        for x in [date.today(),
+                  time(),
+                  datetime.utcnow(),
+                  timedelta(),
+                  tzinfo(),
+                  timezone(timedelta())]:
+            with self.assertRaises(AttributeError):
+                x.abc = 1
+
+    def test_check_arg_types(self):
+        class Number:
+            def __init__(self, value):
+                self.value = value
+            def __int__(self):
+                return self.value
+
+        for xx in [decimal.Decimal(10),
+                   decimal.Decimal('10.9'),
+                   Number(10)]:
+            self.assertEqual(datetime(10, 10, 10, 10, 10, 10, 10),
+                             datetime(xx, xx, xx, xx, xx, xx, xx))
+
+        with self.assertRaisesRegex(TypeError, '^an integer is required '
+                                               '\(got type str\)$'):
+            datetime(10, 10, '10')
+
+        f10 = Number(10.9)
+        with self.assertRaisesRegex(TypeError, '^__int__ returned non-int '
+                                               '\(type float\)$'):
+            datetime(10, 10, f10)
+
+        class Float(float):
+            pass
+        s10 = Float(10.9)
+        with self.assertRaisesRegex(TypeError, '^integer argument expected, '
+                                               'got float$'):
+            datetime(10, 10, s10)
+
+        with self.assertRaises(TypeError):
+            datetime(10., 10, 10)
+        with self.assertRaises(TypeError):
+            datetime(10, 10., 10)
+        with self.assertRaises(TypeError):
+            datetime(10, 10, 10.)
+        with self.assertRaises(TypeError):
+            datetime(10, 10, 10, 10.)
+        with self.assertRaises(TypeError):
+            datetime(10, 10, 10, 10, 10.)
+        with self.assertRaises(TypeError):
+            datetime(10, 10, 10, 10, 10, 10.)
+        with self.assertRaises(TypeError):
+            datetime(10, 10, 10, 10, 10, 10, 10.)
+
 def test_main():
     support.run_unittest(__name__)
 
diff --git a/Lib/test/eintrdata/eintr_tester.py b/Lib/test/eintrdata/eintr_tester.py
new file mode 100644
index 0000000000..40dca847d0
--- /dev/null
+++ b/Lib/test/eintrdata/eintr_tester.py
@@ -0,0 +1,260 @@
+"""
+This test suite exercises some system calls subject to interruption with EINTR,
+to check that it is actually handled transparently.
+It is intended to be run by the main test suite within a child process, to
+ensure there is no background thread running (so that signals are delivered to
+the correct thread).
+Signals are generated in-process using setitimer(ITIMER_REAL), which allows
+sub-second periodicity (contrarily to signal()).
+"""
+
+import io
+import os
+import signal
+import socket
+import time
+import unittest
+
+from test import support
+
+
+@unittest.skipUnless(hasattr(signal, "setitimer"), "requires setitimer()")
+class EINTRBaseTest(unittest.TestCase):
+    """ Base class for EINTR tests. """
+
+    # delay for initial signal delivery
+    signal_delay = 0.1
+    # signal delivery periodicity
+    signal_period = 0.1
+    # default sleep time for tests - should obviously have:
+    # sleep_time > signal_period
+    sleep_time = 0.2
+
+    @classmethod
+    def setUpClass(cls):
+        cls.orig_handler = signal.signal(signal.SIGALRM, lambda *args: None)
+        signal.setitimer(signal.ITIMER_REAL, cls.signal_delay,
+                         cls.signal_period)
+
+    @classmethod
+    def tearDownClass(cls):
+        signal.setitimer(signal.ITIMER_REAL, 0, 0)
+        signal.signal(signal.SIGALRM, cls.orig_handler)
+
+    @classmethod
+    def _sleep(cls):
+        # default sleep time
+        time.sleep(cls.sleep_time)
+
+
+@unittest.skipUnless(hasattr(signal, "setitimer"), "requires setitimer()")
+class OSEINTRTest(EINTRBaseTest):
+    """ EINTR tests for the os module. """
+
+    def _test_wait_multiple(self, wait_func):
+        num = 3
+        for _ in range(num):
+            pid = os.fork()
+            if pid == 0:
+                self._sleep()
+                os._exit(0)
+        for _ in range(num):
+            wait_func()
+
+    def test_wait(self):
+        self._test_wait_multiple(os.wait)
+
+    @unittest.skipUnless(hasattr(os, 'wait3'), 'requires wait3()')
+    def test_wait3(self):
+        self._test_wait_multiple(lambda: os.wait3(0))
+
+    def _test_wait_single(self, wait_func):
+        pid = os.fork()
+        if pid == 0:
+            self._sleep()
+            os._exit(0)
+        else:
+            wait_func(pid)
+
+    def test_waitpid(self):
+        self._test_wait_single(lambda pid: os.waitpid(pid, 0))
+
+    @unittest.skipUnless(hasattr(os, 'wait4'), 'requires wait4()')
+    def test_wait4(self):
+        self._test_wait_single(lambda pid: os.wait4(pid, 0))
+
+    def test_read(self):
+        rd, wr = os.pipe()
+        self.addCleanup(os.close, rd)
+        # wr closed explicitly by parent
+
+        # the payload below are smaller than PIPE_BUF, hence the writes will be
+        # atomic
+        datas = [b"hello", b"world", b"spam"]
+
+        pid = os.fork()
+        if pid == 0:
+            os.close(rd)
+            for data in datas:
+                # let the parent block on read()
+                self._sleep()
+                os.write(wr, data)
+            os._exit(0)
+        else:
+            self.addCleanup(os.waitpid, pid, 0)
+            os.close(wr)
+            for data in datas:
+                self.assertEqual(data, os.read(rd, len(data)))
+
+    def test_write(self):
+        rd, wr = os.pipe()
+        self.addCleanup(os.close, wr)
+        # rd closed explicitly by parent
+
+        # we must write enough data for the write() to block
+        data = b"xyz" * support.PIPE_MAX_SIZE
+
+        pid = os.fork()
+        if pid == 0:
+            os.close(wr)
+            read_data = io.BytesIO()
+            # let the parent block on write()
+            self._sleep()
+            while len(read_data.getvalue()) < len(data):
+                chunk = os.read(rd, 2 * len(data))
+                read_data.write(chunk)
+            self.assertEqual(read_data.getvalue(), data)
+            os._exit(0)
+        else:
+            os.close(rd)
+            written = 0
+            while written < len(data):
+                written += os.write(wr, memoryview(data)[written:])
+            self.assertEqual(0, os.waitpid(pid, 0)[1])
+
+
+@unittest.skipUnless(hasattr(signal, "setitimer"), "requires setitimer()")
+class SocketEINTRTest(EINTRBaseTest):
+    """ EINTR tests for the socket module. """
+
+    @unittest.skipUnless(hasattr(socket, 'socketpair'), 'needs socketpair()')
+    def _test_recv(self, recv_func):
+        rd, wr = socket.socketpair()
+        self.addCleanup(rd.close)
+        # wr closed explicitly by parent
+
+        # single-byte payload guard us against partial recv
+        datas = [b"x", b"y", b"z"]
+
+        pid = os.fork()
+        if pid == 0:
+            rd.close()
+            for data in datas:
+                # let the parent block on recv()
+                self._sleep()
+                wr.sendall(data)
+            os._exit(0)
+        else:
+            self.addCleanup(os.waitpid, pid, 0)
+            wr.close()
+            for data in datas:
+                self.assertEqual(data, recv_func(rd, len(data)))
+
+    def test_recv(self):
+        self._test_recv(socket.socket.recv)
+
+    @unittest.skipUnless(hasattr(socket.socket, 'recvmsg'), 'needs recvmsg()')
+    def test_recvmsg(self):
+        self._test_recv(lambda sock, data: sock.recvmsg(data)[0])
+
+    def _test_send(self, send_func):
+        rd, wr = socket.socketpair()
+        self.addCleanup(wr.close)
+        # rd closed explicitly by parent
+
+        # we must send enough data for the send() to block
+        data = b"xyz" * (support.SOCK_MAX_SIZE // 3)
+
+        pid = os.fork()
+        if pid == 0:
+            wr.close()
+            # let the parent block on send()
+            self._sleep()
+            received_data = bytearray(len(data))
+            n = 0
+            while n < len(data):
+                n += rd.recv_into(memoryview(received_data)[n:])
+            self.assertEqual(received_data, data)
+            os._exit(0)
+        else:
+            rd.close()
+            written = 0
+            while written < len(data):
+                sent = send_func(wr, memoryview(data)[written:])
+                # sendall() returns None
+                written += len(data) if sent is None else sent
+            self.assertEqual(0, os.waitpid(pid, 0)[1])
+
+    def test_send(self):
+        self._test_send(socket.socket.send)
+
+    def test_sendall(self):
+        self._test_send(socket.socket.sendall)
+
+    @unittest.skipUnless(hasattr(socket.socket, 'sendmsg'), 'needs sendmsg()')
+    def test_sendmsg(self):
+        self._test_send(lambda sock, data: sock.sendmsg([data]))
+
+    def test_accept(self):
+        sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+        self.addCleanup(sock.close)
+
+        sock.bind((support.HOST, 0))
+        _, port = sock.getsockname()
+        sock.listen()
+
+        pid = os.fork()
+        if pid == 0:
+            # let parent block on accept()
+            self._sleep()
+            with socket.create_connection((support.HOST, port)):
+                self._sleep()
+            os._exit(0)
+        else:
+            self.addCleanup(os.waitpid, pid, 0)
+            client_sock, _ = sock.accept()
+            client_sock.close()
+
+    @unittest.skipUnless(hasattr(os, 'mkfifo'), 'needs mkfifo()')
+    def _test_open(self, do_open_close_reader, do_open_close_writer):
+        # Use a fifo: until the child opens it for reading, the parent will
+        # block when trying to open it for writing.
+        support.unlink(support.TESTFN)
+        os.mkfifo(support.TESTFN)
+        self.addCleanup(support.unlink, support.TESTFN)
+
+        pid = os.fork()
+        if pid == 0:
+            # let the parent block
+            self._sleep()
+            do_open_close_reader(support.TESTFN)
+            os._exit(0)
+        else:
+            self.addCleanup(os.waitpid, pid, 0)
+            do_open_close_writer(support.TESTFN)
+
+    def test_open(self):
+        self._test_open(lambda path: open(path, 'r').close(),
+                        lambda path: open(path, 'w').close())
+
+    def test_os_open(self):
+        self._test_open(lambda path: os.close(os.open(path, os.O_RDONLY)),
+                        lambda path: os.close(os.open(path, os.O_WRONLY)))
+
+
+def test_main():
+    support.run_unittest(OSEINTRTest, SocketEINTRTest)
+
+
+if __name__ == "__main__":
+    test_main()
diff --git a/Lib/test/fork_wait.py b/Lib/test/fork_wait.py
index 19b54ec736..713039dd82 100644
--- a/Lib/test/fork_wait.py
+++ b/Lib/test/fork_wait.py
@@ -48,7 +48,12 @@ class ForkWait(unittest.TestCase):
         for i in range(NUM_THREADS):
             _thread.start_new(self.f, (i,))
 
-        time.sleep(LONGSLEEP)
+        # busy-loop to wait for threads
+        deadline = time.monotonic() + 10.0
+        while len(self.alive) < NUM_THREADS:
+            time.sleep(0.1)
+            if deadline < time.monotonic():
+                break
 
         a = sorted(self.alive.keys())
         self.assertEqual(a, list(range(NUM_THREADS)))
diff --git a/Lib/test/imghdrdata/python.exr b/Lib/test/imghdrdata/python.exr
new file mode 100644
index 0000000000..773c81ee1f
--- /dev/null
+++ b/Lib/test/imghdrdata/python.exr
diff --git a/Lib/test/imghdrdata/python.webp b/Lib/test/imghdrdata/python.webp
new file mode 100644
index 0000000000..e824ec7fb1
--- /dev/null
+++ b/Lib/test/imghdrdata/python.webp
diff --git a/Lib/test/inspect_fodder2.py b/Lib/test/inspect_fodder2.py
index bd7106fea8..e452235cd8 100644
--- a/Lib/test/inspect_fodder2.py
+++ b/Lib/test/inspect_fodder2.py
@@ -109,3 +109,16 @@ def annotated(arg1: list):
 #line 109
 def keyword_only_arg(*, arg):
     pass
+
+from functools import wraps
+
+def decorator(func):
+    @wraps(func)
+    def fake():
+        return 42
+    return fake
+
+#line 121
+@decorator
+def real():
+    return 20
diff --git a/Lib/test/list_tests.py b/Lib/test/list_tests.py
index 42e118ba8f..906933796d 100644
--- a/Lib/test/list_tests.py
+++ b/Lib/test/list_tests.py
@@ -30,6 +30,12 @@ class CommonTest(seq_tests.CommonTest):
         self.assertNotEqual(id(a), id(b))
         self.assertEqual(a, b)
 
+    def test_getitem_error(self):
+        msg = "list indices must be integers or slices"
+        with self.assertRaisesRegex(TypeError, msg):
+            a = []
+            a['a'] = "python"
+
     def test_repr(self):
         l0 = []
         l2 = [0, 1, 2]
@@ -120,6 +126,10 @@ class CommonTest(seq_tests.CommonTest):
         a[-1] = 9
         self.assertEqual(a, self.type2test([5,6,7,8,9]))
 
+        msg = "list indices must be integers or slices"
+        with self.assertRaisesRegex(TypeError, msg):
+            a['a'] = "python"
+
     def test_delitem(self):
         a = self.type2test([0, 1])
         del a[1]
diff --git a/Lib/test/lock_tests.py b/Lib/test/lock_tests.py
index 1cbcea2343..136f1c37c6 100644
--- a/Lib/test/lock_tests.py
+++ b/Lib/test/lock_tests.py
@@ -82,7 +82,13 @@ class BaseLockTests(BaseTestCase):
 
     def test_repr(self):
         lock = self.locktype()
-        repr(lock)
+        self.assertRegex(repr(lock), "<unlocked .* object (.*)?at .*>")
+        del lock
+
+    def test_locked_repr(self):
+        lock = self.locktype()
+        lock.acquire()
+        self.assertRegex(repr(lock), "<locked .* object (.*)?at .*>")
         del lock
 
     def test_acquire_destroy(self):
diff --git a/Lib/test/mock_socket.py b/Lib/test/mock_socket.py
index e36724f54b..b28c4732cc 100644
--- a/Lib/test/mock_socket.py
+++ b/Lib/test/mock_socket.py
@@ -35,8 +35,9 @@ class MockFile:
 class MockSocket:
     """Mock socket object used by smtpd and smtplib tests.
     """
-    def __init__(self):
+    def __init__(self, family=None):
         global _reply_data
+        self.family = family
         self.output = []
         self.lines = []
         if _reply_data:
@@ -101,15 +102,14 @@ class MockSocket:
         return len(data)
 
     def getpeername(self):
-        return 'peer'
+        return ('peer-address', 'peer-port')
 
     def close(self):
         pass
 
 
 def socket(family=None, type=None, proto=None):
-    return MockSocket()
-
+    return MockSocket(family)
 
 def create_connection(address, timeout=socket_module._GLOBAL_DEFAULT_TIMEOUT,
                       source_address=None):
@@ -144,13 +144,16 @@ def gethostname():
 def gethostbyname(name):
     return ""
 
+def getaddrinfo(*args, **kw):
+    return socket_module.getaddrinfo(*args, **kw)
 
 gaierror = socket_module.gaierror
 error = socket_module.error
 
 
 # Constants
-AF_INET = None
-SOCK_STREAM = None
+AF_INET = socket_module.AF_INET
+AF_INET6 = socket_module.AF_INET6
+SOCK_STREAM = socket_module.SOCK_STREAM
 SOL_SOCKET = None
 SO_REUSEADDR = None
diff --git a/Lib/test/pickletester.py b/Lib/test/pickletester.py
index 55205d10d5..f8372e32e6 100644
--- a/Lib/test/pickletester.py
+++ b/Lib/test/pickletester.py
@@ -1154,16 +1154,62 @@ class AbstractPickleTests(unittest.TestCase):
                 self.assertGreaterEqual(num_additems, 2)
 
     def test_simple_newobj(self):
-        x = object.__new__(SimpleNewObj)  # avoid __init__
+        x = SimpleNewObj.__new__(SimpleNewObj, 0xface)  # avoid __init__
         x.abc = 666
         for proto in protocols:
-            s = self.dumps(x, proto)
-            self.assertEqual(opcode_in_pickle(pickle.NEWOBJ, s),
-                             2 <= proto < 4)
-            self.assertEqual(opcode_in_pickle(pickle.NEWOBJ_EX, s),
-                             proto >= 4)
-            y = self.loads(s)   # will raise TypeError if __init__ called
-            self.assert_is_copy(x, y)
+            with self.subTest(proto=proto):
+                s = self.dumps(x, proto)
+                if proto < 1:
+                    self.assertIn(b'\nL64206', s)  # LONG
+                else:
+                    self.assertIn(b'M\xce\xfa', s)  # BININT2
+                self.assertEqual(opcode_in_pickle(pickle.NEWOBJ, s),
+                                 2 <= proto)
+                self.assertFalse(opcode_in_pickle(pickle.NEWOBJ_EX, s))
+                y = self.loads(s)   # will raise TypeError if __init__ called
+                self.assert_is_copy(x, y)
+
+    def test_complex_newobj(self):
+        x = ComplexNewObj.__new__(ComplexNewObj, 0xface)  # avoid __init__
+        x.abc = 666
+        for proto in protocols:
+            with self.subTest(proto=proto):
+                s = self.dumps(x, proto)
+                if proto < 1:
+                    self.assertIn(b'\nL64206', s)  # LONG
+                elif proto < 2:
+                    self.assertIn(b'M\xce\xfa', s)  # BININT2
+                elif proto < 4:
+                    self.assertIn(b'X\x04\x00\x00\x00FACE', s)  # BINUNICODE
+                else:
+                    self.assertIn(b'\x8c\x04FACE', s)  # SHORT_BINUNICODE
+                self.assertEqual(opcode_in_pickle(pickle.NEWOBJ, s),
+                                 2 <= proto)
+                self.assertFalse(opcode_in_pickle(pickle.NEWOBJ_EX, s))
+                y = self.loads(s)   # will raise TypeError if __init__ called
+                self.assert_is_copy(x, y)
+
+    def test_complex_newobj_ex(self):
+        x = ComplexNewObjEx.__new__(ComplexNewObjEx, 0xface)  # avoid __init__
+        x.abc = 666
+        for proto in protocols:
+            with self.subTest(proto=proto):
+                if 2 <= proto < 4:
+                    self.assertRaises(ValueError, self.dumps, x, proto)
+                    continue
+                s = self.dumps(x, proto)
+                if proto < 1:
+                    self.assertIn(b'\nL64206', s)  # LONG
+                elif proto < 2:
+                    self.assertIn(b'M\xce\xfa', s)  # BININT2
+                else:
+                    assert proto >= 4
+                    self.assertIn(b'\x8c\x04FACE', s)  # SHORT_BINUNICODE
+                self.assertFalse(opcode_in_pickle(pickle.NEWOBJ, s))
+                self.assertEqual(opcode_in_pickle(pickle.NEWOBJ_EX, s),
+                                 4 <= proto)
+                y = self.loads(s)   # will raise TypeError if __init__ called
+                self.assert_is_copy(x, y)
 
     def test_newobj_list_slots(self):
         x = SlotList([1, 2, 3])
@@ -1645,6 +1691,27 @@ class AbstractPickleTests(unittest.TestCase):
                     unpickled = self.loads(self.dumps(method, proto))
                     self.assertEqual(method(*args), unpickled(*args))
 
+    def test_local_lookup_error(self):
+        # Test that whichmodule() errors out cleanly when looking up
+        # an assumed globally-reachable object fails.
+        def f():
+            pass
+        # Since the function is local, lookup will fail
+        for proto in range(0, pickle.HIGHEST_PROTOCOL + 1):
+            with self.assertRaises((AttributeError, pickle.PicklingError)):
+                pickletools.dis(self.dumps(f, proto))
+        # Same without a __module__ attribute (exercises a different path
+        # in _pickle.c).
+        del f.__module__
+        for proto in range(0, pickle.HIGHEST_PROTOCOL + 1):
+            with self.assertRaises((AttributeError, pickle.PicklingError)):
+                pickletools.dis(self.dumps(f, proto))
+        # Yet a different path.
+        f.__name__ = f.__qualname__
+        for proto in range(0, pickle.HIGHEST_PROTOCOL + 1):
+            with self.assertRaises((AttributeError, pickle.PicklingError)):
+                pickletools.dis(self.dumps(f, proto))
+
 
 class BigmemPickleTests(unittest.TestCase):
 
@@ -1879,12 +1946,20 @@ myclasses = [MyInt, MyFloat,
 class SlotList(MyList):
     __slots__ = ["foo"]
 
-class SimpleNewObj(object):
-    def __init__(self, a, b, c):
+class SimpleNewObj(int):
+    def __init__(self, *args, **kwargs):
         # raise an error, to make sure this isn't called
         raise TypeError("SimpleNewObj.__init__() didn't expect to get called")
     def __eq__(self, other):
-        return self.__dict__ == other.__dict__
+        return int(self) == int(other) and self.__dict__ == other.__dict__
+
+class ComplexNewObj(SimpleNewObj):
+    def __getnewargs__(self):
+        return ('%X' % self, 16)
+
+class ComplexNewObjEx(SimpleNewObj):
+    def __getnewargs_ex__(self):
+        return ('%X' % self,), {'base': 16}
 
 class BadGetattr:
     def __getattr__(self, key):
diff --git a/Lib/test/pystone.py b/Lib/test/pystone.py
index a41f1e53a5..1f67e66e3f 100755
--- a/Lib/test/pystone.py
+++ b/Lib/test/pystone.py
@@ -41,7 +41,7 @@ Version History:
 
 LOOPS = 50000
 
-from time import clock
+from time import time
 
 __version__ = "1.2"
 
@@ -93,10 +93,10 @@ def Proc0(loops=LOOPS):
     global PtrGlb
     global PtrGlbNext
 
-    starttime = clock()
+    starttime = time()
     for i in range(loops):
         pass
-    nulltime = clock() - starttime
+    nulltime = time() - starttime
 
     PtrGlbNext = Record()
     PtrGlb = Record()
@@ -108,7 +108,7 @@ def Proc0(loops=LOOPS):
     String1Loc = "DHRYSTONE PROGRAM, 1'ST STRING"
     Array2Glob[8][7] = 10
 
-    starttime = clock()
+    starttime = time()
 
     for i in range(loops):
         Proc5()
@@ -134,7 +134,7 @@ def Proc0(loops=LOOPS):
         IntLoc2 = 7 * (IntLoc3 - IntLoc2) - IntLoc1
         IntLoc1 = Proc2(IntLoc1)
 
-    benchtime = clock() - starttime - nulltime
+    benchtime = time() - starttime - nulltime
     if benchtime == 0.0:
         loopsPerBenchtime = 0.0
     else:
diff --git a/Lib/test/regrtest.py b/Lib/test/regrtest.py
index b633631b00..ea1287ddde 100755
--- a/Lib/test/regrtest.py
+++ b/Lib/test/regrtest.py
@@ -1276,6 +1276,10 @@ def runtest_inner(test, verbose, quiet,
                 def test_runner():
                     loader = unittest.TestLoader()
                     tests = loader.loadTestsFromModule(the_module)
+                    for error in loader.errors:
+                        print(error, file=sys.stderr)
+                    if loader.errors:
+                        raise Exception("errors while loading tests")
                     support.run_unittest(tests)
             test_runner()
             if huntrleaks:
diff --git a/Lib/test/script_helper.py b/Lib/test/script_helper.py
index 8c599d1b04..5531a34b62 100644
--- a/Lib/test/script_helper.py
+++ b/Lib/test/script_helper.py
@@ -19,7 +19,7 @@ from test.support import make_legacy_pyc, strip_python_stderr, temp_dir
 # Cached result of the expensive test performed in the function below.
 __cached_interp_requires_environment = None
 
-def _interpreter_requires_environment():
+def interpreter_requires_environment():
     """
     Returns True if our sys.executable interpreter requires environment
     variables in order to be able to run at all.
@@ -52,7 +52,7 @@ def _interpreter_requires_environment():
 
 # Executing the interpreter in a subprocess
 def _assert_python(expected_success, *args, **env_vars):
-    env_required = _interpreter_requires_environment()
+    env_required = interpreter_requires_environment()
     if '__isolated' in env_vars:
         isolated = env_vars.pop('__isolated')
     else:
diff --git a/Lib/test/ssl_servers.py b/Lib/test/ssl_servers.py
index 759b3f487e..f9d30cf0bd 100644
--- a/Lib/test/ssl_servers.py
+++ b/Lib/test/ssl_servers.py
@@ -150,7 +150,7 @@ class HTTPSServerThread(threading.Thread):
 def make_https_server(case, *, context=None, certfile=CERTFILE,
                       host=HOST, handler_class=None):
     if context is None:
-        context = ssl.SSLContext(ssl.PROTOCOL_SSLv23)
+        context = ssl.create_default_context(ssl.Purpose.CLIENT_AUTH)
     # We assume the certfile contains both private key and certificate
     context.load_cert_chain(certfile)
     server = HTTPSServerThread(context, host, handler_class)
@@ -182,6 +182,8 @@ if __name__ == "__main__":
     parser.add_argument('--curve-name', dest='curve_name', type=str,
                         action='store',
                         help='curve name for EC-based Diffie-Hellman')
+    parser.add_argument('--ciphers', dest='ciphers', type=str,
+                        help='allowed cipher list')
     parser.add_argument('--dh', dest='dh_file', type=str, action='store',
                         help='PEM file containing DH parameters')
     args = parser.parse_args()
@@ -192,12 +194,14 @@ if __name__ == "__main__":
     else:
         handler_class = RootedHTTPRequestHandler
         handler_class.root = os.getcwd()
-    context = ssl.SSLContext(ssl.PROTOCOL_TLSv1)
+    context = ssl.create_default_context(ssl.Purpose.CLIENT_AUTH)
     context.load_cert_chain(CERTFILE)
     if args.curve_name:
         context.set_ecdh_curve(args.curve_name)
     if args.dh_file:
         context.load_dh_params(args.dh_file)
+    if args.ciphers:
+        context.set_ciphers(args.ciphers)
 
     server = HTTPSServer(("", args.port), handler_class, context)
     if args.verbose:
diff --git a/Lib/test/string_tests.py b/Lib/test/string_tests.py
index 242a931ec6..6e26474a3b 100644
--- a/Lib/test/string_tests.py
+++ b/Lib/test/string_tests.py
@@ -1176,8 +1176,7 @@ class MixinStrUnicodeUserStringTest:
         self.checkraises(TypeError, 'abc', '__mod__')
         self.checkraises(TypeError, '%(foo)s', '__mod__', 42)
         self.checkraises(TypeError, '%s%s', '__mod__', (42,))
-        with self.assertWarns(DeprecationWarning):
-            self.checkraises(TypeError, '%c', '__mod__', (None,))
+        self.checkraises(TypeError, '%c', '__mod__', (None,))
         self.checkraises(ValueError, '%(foo', '__mod__', {})
         self.checkraises(TypeError, '%(foo)s %(bar)s', '__mod__', ('foo', 42))
         self.checkraises(TypeError, '%d', '__mod__', "42") # not numeric
diff --git a/Lib/test/support/__init__.py b/Lib/test/support/__init__.py
index d98068cac8..205c47c0c1 100644
--- a/Lib/test/support/__init__.py
+++ b/Lib/test/support/__init__.py
@@ -1040,7 +1040,8 @@ def open_urlresource(url, *args, **kw):
     # Verify the requirement before downloading the file
     requires('urlfetch')
 
-    print('\tfetching %s ...' % url, file=get_original_stdout())
+    if verbose:
+        print('\tfetching %s ...' % url, file=get_original_stdout())
     opener = urllib.request.build_opener()
     if gzip:
         opener.addheaders.append(('Accept-Encoding', 'gzip'))
diff --git a/Lib/test/test_argparse.py b/Lib/test/test_argparse.py
index 1164f3feb9..d7f90cdaa9 100644
--- a/Lib/test/test_argparse.py
+++ b/Lib/test/test_argparse.py
@@ -20,15 +20,6 @@ class StdIOBuffer(StringIO):
 
 class TestCase(unittest.TestCase):
 
-    def assertEqual(self, obj1, obj2):
-        if obj1 != obj2:
-            print('')
-            print(repr(obj1))
-            print(repr(obj2))
-            print(obj1)
-            print(obj2)
-        super(TestCase, self).assertEqual(obj1, obj2)
-
     def setUp(self):
         # The tests assume that line wrapping occurs at 80 columns, but this
         # behaviour can be overridden by setting the COLUMNS environment
@@ -78,9 +69,6 @@ class NS(object):
     def __eq__(self, other):
         return vars(self) == vars(other)
 
-    def __ne__(self, other):
-        return not (self == other)
-
 
 class ArgumentParserError(Exception):
 
@@ -765,6 +753,39 @@ class TestOptionalsActionCount(ParserTestCase):
     ]
 
 
+class TestOptionalsAllowLongAbbreviation(ParserTestCase):
+    """Allow long options to be abbreviated unambiguously"""
+
+    argument_signatures = [
+        Sig('--foo'),
+        Sig('--foobaz'),
+        Sig('--fooble', action='store_true'),
+    ]
+    failures = ['--foob 5', '--foob']
+    successes = [
+        ('', NS(foo=None, foobaz=None, fooble=False)),
+        ('--foo 7', NS(foo='7', foobaz=None, fooble=False)),
+        ('--fooba a', NS(foo=None, foobaz='a', fooble=False)),
+        ('--foobl --foo g', NS(foo='g', foobaz=None, fooble=True)),
+    ]
+
+
+class TestOptionalsDisallowLongAbbreviation(ParserTestCase):
+    """Do not allow abbreviations of long options at all"""
+
+    parser_signature = Sig(allow_abbrev=False)
+    argument_signatures = [
+        Sig('--foo'),
+        Sig('--foodle', action='store_true'),
+        Sig('--foonly'),
+    ]
+    failures = ['-foon 3', '--foon 3', '--food', '--food --foo 2']
+    successes = [
+        ('', NS(foo=None, foodle=False, foonly=None)),
+        ('--foo 3', NS(foo='3', foodle=False, foonly=None)),
+        ('--foonly 7 --foodle --foo 2', NS(foo='2', foodle=True, foonly='7')),
+    ]
+
 # ================
 # Positional tests
 # ================
@@ -1993,14 +2014,9 @@ class TestAddSubparsers(TestCase):
             '''))
 
     def _test_subparser_help(self, args_str, expected_help):
-        try:
+        with self.assertRaises(ArgumentParserError) as cm:
             self.parser.parse_args(args_str.split())
-        except ArgumentParserError:
-            err = sys.exc_info()[1]
-            if err.stdout != expected_help:
-                print(repr(expected_help))
-                print(repr(err.stdout))
-            self.assertEqual(err.stdout, expected_help)
+        self.assertEqual(expected_help, cm.exception.stdout)
 
     def test_subparser1_help(self):
         self._test_subparser_help('5.0 1 -h', textwrap.dedent('''\
@@ -2846,15 +2862,15 @@ class TestGetDefault(TestCase):
 
     def test_get_default(self):
         parser = ErrorRaisingArgumentParser()
-        self.assertEqual(None, parser.get_default("foo"))
-        self.assertEqual(None, parser.get_default("bar"))
+        self.assertIsNone(parser.get_default("foo"))
+        self.assertIsNone(parser.get_default("bar"))
 
         parser.add_argument("--foo")
-        self.assertEqual(None, parser.get_default("foo"))
-        self.assertEqual(None, parser.get_default("bar"))
+        self.assertIsNone(parser.get_default("foo"))
+        self.assertIsNone(parser.get_default("bar"))
 
         parser.add_argument("--bar", type=int, default=42)
-        self.assertEqual(None, parser.get_default("foo"))
+        self.assertIsNone(parser.get_default("foo"))
         self.assertEqual(42, parser.get_default("bar"))
 
         parser.set_defaults(foo="badger")
@@ -2869,18 +2885,16 @@ class TestNamespaceContainsSimple(TestCase):
 
     def test_empty(self):
         ns = argparse.Namespace()
-        self.assertEqual('' in ns, False)
-        self.assertEqual('' not in ns, True)
-        self.assertEqual('x' in ns, False)
+        self.assertNotIn('', ns)
+        self.assertNotIn('x', ns)
 
     def test_non_empty(self):
         ns = argparse.Namespace(x=1, y=2)
-        self.assertEqual('x' in ns, True)
-        self.assertEqual('x' not in ns, False)
-        self.assertEqual('y' in ns, True)
-        self.assertEqual('' in ns, False)
-        self.assertEqual('xx' in ns, False)
-        self.assertEqual('z' in ns, False)
+        self.assertNotIn('', ns)
+        self.assertIn('x', ns)
+        self.assertIn('y', ns)
+        self.assertNotIn('xx', ns)
+        self.assertNotIn('z', ns)
 
 # =====================
 # Help formatting tests
@@ -2936,13 +2950,6 @@ class TestHelpFormattingMetaclass(type):
             def _test(self, tester, parser_text):
                 expected_text = getattr(tester, self.func_suffix)
                 expected_text = textwrap.dedent(expected_text)
-                if expected_text != parser_text:
-                    print(repr(expected_text))
-                    print(repr(parser_text))
-                    for char1, char2 in zip(expected_text, parser_text):
-                        if char1 != char2:
-                            print('first diff: %r %r' % (char1, char2))
-                            break
                 tester.assertEqual(expected_text, parser_text)
 
             def test_format(self, tester):
@@ -4223,24 +4230,17 @@ class TestInvalidArgumentConstructors(TestCase):
         self.assertValueError('foo', action='baz')
         self.assertValueError('--foo', action=('store', 'append'))
         parser = argparse.ArgumentParser()
-        try:
+        with self.assertRaises(ValueError) as cm:
             parser.add_argument("--foo", action="store-true")
-        except ValueError:
-            e = sys.exc_info()[1]
-            expected = 'unknown action'
-            msg = 'expected %r, found %r' % (expected, e)
-            self.assertTrue(expected in str(e), msg)
+        self.assertIn('unknown action', str(cm.exception))
 
     def test_multiple_dest(self):
         parser = argparse.ArgumentParser()
         parser.add_argument(dest='foo')
-        try:
+        with self.assertRaises(ValueError) as cm:
             parser.add_argument('bar', dest='baz')
-        except ValueError:
-            e = sys.exc_info()[1]
-            expected = 'dest supplied twice for positional argument'
-            msg = 'expected %r, found %r' % (expected, e)
-            self.assertTrue(expected in str(e), msg)
+        self.assertIn('dest supplied twice for positional argument',
+                      str(cm.exception))
 
     def test_no_argument_actions(self):
         for action in ['store_const', 'store_true', 'store_false',
@@ -4397,18 +4397,10 @@ class TestConflictHandling(TestCase):
 class TestOptionalsHelpVersionActions(TestCase):
     """Test the help and version actions"""
 
-    def _get_error(self, func, *args, **kwargs):
-        try:
-            func(*args, **kwargs)
-        except ArgumentParserError:
-            return sys.exc_info()[1]
-        else:
-            self.assertRaises(ArgumentParserError, func, *args, **kwargs)
-
     def assertPrintHelpExit(self, parser, args_str):
-        self.assertEqual(
-            parser.format_help(),
-            self._get_error(parser.parse_args, args_str.split()).stdout)
+        with self.assertRaises(ArgumentParserError) as cm:
+            parser.parse_args(args_str.split())
+        self.assertEqual(parser.format_help(), cm.exception.stdout)
 
     def assertArgumentParserError(self, parser, *args):
         self.assertRaises(ArgumentParserError, parser.parse_args, args)
@@ -4423,8 +4415,9 @@ class TestOptionalsHelpVersionActions(TestCase):
     def test_version_format(self):
         parser = ErrorRaisingArgumentParser(prog='PPP')
         parser.add_argument('-v', '--version', action='version', version='%(prog)s 3.5')
-        msg = self._get_error(parser.parse_args, ['-v']).stdout
-        self.assertEqual('PPP 3.5\n', msg)
+        with self.assertRaises(ArgumentParserError) as cm:
+            parser.parse_args(['-v'])
+        self.assertEqual('PPP 3.5\n', cm.exception.stdout)
 
     def test_version_no_help(self):
         parser = ErrorRaisingArgumentParser(add_help=False)
@@ -4436,8 +4429,9 @@ class TestOptionalsHelpVersionActions(TestCase):
     def test_version_action(self):
         parser = ErrorRaisingArgumentParser(prog='XXX')
         parser.add_argument('-V', action='version', version='%(prog)s 3.7')
-        msg = self._get_error(parser.parse_args, ['-V']).stdout
-        self.assertEqual('XXX 3.7\n', msg)
+        with self.assertRaises(ArgumentParserError) as cm:
+            parser.parse_args(['-V'])
+        self.assertEqual('XXX 3.7\n', cm.exception.stdout)
 
     def test_no_help(self):
         parser = ErrorRaisingArgumentParser(add_help=False)
@@ -4607,14 +4601,10 @@ class TestArgumentTypeError(TestCase):
 
         parser = ErrorRaisingArgumentParser(prog='PROG', add_help=False)
         parser.add_argument('x', type=spam)
-        try:
+        with self.assertRaises(ArgumentParserError) as cm:
             parser.parse_args(['XXX'])
-        except ArgumentParserError:
-            expected = 'usage: PROG x\nPROG: error: argument x: spam!\n'
-            msg = sys.exc_info()[1].stderr
-            self.assertEqual(expected, msg)
-        else:
-            self.fail()
+        self.assertEqual('usage: PROG x\nPROG: error: argument x: spam!\n',
+                         cm.exception.stderr)
 
 # =========================
 # MessageContentError tests
diff --git a/Lib/test/test_array.py b/Lib/test/test_array.py
index 07c9bf999b..10d99462fd 100644
--- a/Lib/test/test_array.py
+++ b/Lib/test/test_array.py
@@ -394,7 +394,9 @@ class BaseTest:
         self.assertEqual(a, b)
 
     def test_tofromstring(self):
-        nb_warnings = 4
+        # Warnings not raised when arguments are incorrect as Argument Clinic
+        # handles that before the warning can be raised.
+        nb_warnings = 2
         with warnings.catch_warnings(record=True) as r:
             warnings.filterwarnings("always",
                                     message=r"(to|from)string\(\) is deprecated",
@@ -1039,6 +1041,11 @@ class BaseTest:
             a = array.array(self.typecode, "foo")
             a = array.array(self.typecode, array.array('u', 'foo'))
 
+    @support.cpython_only
+    def test_obsolete_write_lock(self):
+        from _testcapi import getbuffer_with_null_view
+        a = array.array('B', b"")
+        self.assertRaises(BufferError, getbuffer_with_null_view, a)
 
 class StringTest(BaseTest):
 
diff --git a/Lib/test/test_asdl_parser.py b/Lib/test/test_asdl_parser.py
new file mode 100644
index 0000000000..7a6426a4d3
--- /dev/null
+++ b/Lib/test/test_asdl_parser.py
@@ -0,0 +1,122 @@
+"""Tests for the asdl parser in Parser/asdl.py"""
+
+import importlib.machinery
+import os
+from os.path import dirname
+import sys
+import sysconfig
+import unittest
+
+
+# This test is only relevant for from-source builds of Python.
+if not sysconfig.is_python_build():
+    raise unittest.SkipTest('test irrelevant for an installed Python')
+
+src_base = dirname(dirname(dirname(__file__)))
+parser_dir = os.path.join(src_base, 'Parser')
+
+
+class TestAsdlParser(unittest.TestCase):
+    @classmethod
+    def setUpClass(cls):
+        # Loads the asdl module dynamically, since it's not in a real importable
+        # package.
+        # Parses Python.asdl into a ast.Module and run the check on it.
+        # There's no need to do this for each test method, hence setUpClass.
+        sys.path.insert(0, parser_dir)
+        loader = importlib.machinery.SourceFileLoader(
+                'asdl', os.path.join(parser_dir, 'asdl.py'))
+        cls.asdl = loader.load_module()
+        cls.mod = cls.asdl.parse(os.path.join(parser_dir, 'Python.asdl'))
+        cls.assertTrue(cls.asdl.check(cls.mod), 'Module validation failed')
+
+    @classmethod
+    def tearDownClass(cls):
+        del sys.path[0]
+
+    def setUp(self):
+        # alias stuff from the class, for convenience
+        self.asdl = TestAsdlParser.asdl
+        self.mod = TestAsdlParser.mod
+        self.types = self.mod.types
+
+    def test_module(self):
+        self.assertEqual(self.mod.name, 'Python')
+        self.assertIn('stmt', self.types)
+        self.assertIn('expr', self.types)
+        self.assertIn('mod', self.types)
+
+    def test_definitions(self):
+        defs = self.mod.dfns
+        self.assertIsInstance(defs[0], self.asdl.Type)
+        self.assertIsInstance(defs[0].value, self.asdl.Sum)
+
+        self.assertIsInstance(self.types['withitem'], self.asdl.Product)
+        self.assertIsInstance(self.types['alias'], self.asdl.Product)
+
+    def test_product(self):
+        alias = self.types['alias']
+        self.assertEqual(
+            str(alias),
+            'Product([Field(identifier, name), Field(identifier, asname, opt=True)])')
+
+    def test_attributes(self):
+        stmt = self.types['stmt']
+        self.assertEqual(len(stmt.attributes), 2)
+        self.assertEqual(str(stmt.attributes[0]), 'Field(int, lineno)')
+        self.assertEqual(str(stmt.attributes[1]), 'Field(int, col_offset)')
+
+    def test_constructor_fields(self):
+        ehandler = self.types['excepthandler']
+        self.assertEqual(len(ehandler.types), 1)
+        self.assertEqual(len(ehandler.attributes), 2)
+
+        cons = ehandler.types[0]
+        self.assertIsInstance(cons, self.asdl.Constructor)
+        self.assertEqual(len(cons.fields), 3)
+
+        f0 = cons.fields[0]
+        self.assertEqual(f0.type, 'expr')
+        self.assertEqual(f0.name, 'type')
+        self.assertTrue(f0.opt)
+
+        f1 = cons.fields[1]
+        self.assertEqual(f1.type, 'identifier')
+        self.assertEqual(f1.name, 'name')
+        self.assertTrue(f1.opt)
+
+        f2 = cons.fields[2]
+        self.assertEqual(f2.type, 'stmt')
+        self.assertEqual(f2.name, 'body')
+        self.assertFalse(f2.opt)
+        self.assertTrue(f2.seq)
+
+    def test_visitor(self):
+        class CustomVisitor(self.asdl.VisitorBase):
+            def __init__(self):
+                super().__init__()
+                self.names_with_seq = []
+
+            def visitModule(self, mod):
+                for dfn in mod.dfns:
+                    self.visit(dfn)
+
+            def visitType(self, type):
+                self.visit(type.value)
+
+            def visitSum(self, sum):
+                for t in sum.types:
+                    self.visit(t)
+
+            def visitConstructor(self, cons):
+                for f in cons.fields:
+                    if f.seq:
+                        self.names_with_seq.append(cons.name)
+
+        v = CustomVisitor()
+        v.visit(self.types['mod'])
+        self.assertEqual(v.names_with_seq, ['Module', 'Interactive', 'Suite'])
+
+
+if __name__ == '__main__':
+    unittest.main()
diff --git a/Lib/test/test_asynchat.py b/Lib/test/test_asynchat.py
index 2dc9d0c17a..3a33fc8b2d 100644
--- a/Lib/test/test_asynchat.py
+++ b/Lib/test/test_asynchat.py
@@ -12,6 +12,7 @@ import socket
 import sys
 import time
 import unittest
+import warnings
 import unittest.mock
 try:
     import threading
@@ -38,7 +39,7 @@ if threading:
             self.start_resend_event = None
 
         def run(self):
-            self.sock.listen(1)
+            self.sock.listen()
             self.event.set()
             conn, client = self.sock.accept()
             self.buffer = b""
@@ -298,7 +299,10 @@ class TestHelperFunctions(unittest.TestCase):
 
 class TestFifo(unittest.TestCase):
     def test_basic(self):
-        f = asynchat.fifo()
+        with self.assertWarns(DeprecationWarning) as cm:
+            f = asynchat.fifo()
+        self.assertEqual(str(cm.warning),
+                         "fifo class will be removed in Python 3.6")
         f.push(7)
         f.push(b'a')
         self.assertEqual(len(f), 2)
@@ -313,7 +317,10 @@ class TestFifo(unittest.TestCase):
         self.assertEqual(f.pop(), (0, None))
 
     def test_given_list(self):
-        f = asynchat.fifo([b'x', 17, 3])
+        with self.assertWarns(DeprecationWarning) as cm:
+            f = asynchat.fifo([b'x', 17, 3])
+        self.assertEqual(str(cm.warning),
+                         "fifo class will be removed in Python 3.6")
         self.assertEqual(len(f), 3)
         self.assertEqual(f.pop(), (1, b'x'))
         self.assertEqual(f.pop(), (1, 17))
diff --git a/Lib/test/test_asyncore.py b/Lib/test/test_asyncore.py
index d44726d11f..38579168cf 100644
--- a/Lib/test/test_asyncore.py
+++ b/Lib/test/test_asyncore.py
@@ -7,7 +7,6 @@ import sys
 import time
 import errno
 import struct
-import warnings
 
 from test import support
 from io import BytesIO
@@ -65,7 +64,7 @@ class crashingdummy:
 # used when testing senders; just collects what it gets until newline is sent
 def capture_server(evt, buf, serv):
     try:
-        serv.listen(5)
+        serv.listen()
         conn, addr = serv.accept()
     except socket.timeout:
         pass
@@ -298,23 +297,6 @@ class DispatcherTests(unittest.TestCase):
                     'warning: unhandled connect event']
         self.assertEqual(lines, expected)
 
-    def test_issue_8594(self):
-        # XXX - this test is supposed to be removed in next major Python
-        # version
-        d = asyncore.dispatcher(socket.socket())
-        # make sure the error message no longer refers to the socket
-        # object but the dispatcher instance instead
-        self.assertRaisesRegex(AttributeError, 'dispatcher instance',
-                               getattr, d, 'foo')
-        # cheap inheritance with the underlying socket is supposed
-        # to still work but a DeprecationWarning is expected
-        with warnings.catch_warnings(record=True) as w:
-            warnings.simplefilter("always")
-            family = d.family
-            self.assertEqual(family, socket.AF_INET)
-            self.assertEqual(len(w), 1)
-            self.assertTrue(issubclass(w[0].category, DeprecationWarning))
-
     def test_strerror(self):
         # refers to bug #8573
         err = asyncore._strerror(errno.EPERM)
@@ -331,9 +313,8 @@ class dispatcherwithsend_noread(asyncore.dispatcher_with_send):
     def handle_connect(self):
         pass
 
-class DispatcherWithSendTests(unittest.TestCase):
-    usepoll = False
 
+class DispatcherWithSendTests(unittest.TestCase):
     def setUp(self):
         pass
 
@@ -383,10 +364,6 @@ class DispatcherWithSendTests(unittest.TestCase):
                 self.fail("join() timed out")
 
 
-
-class DispatcherWithSendTests_UsePoll(DispatcherWithSendTests):
-    usepoll = True
-
 @unittest.skipUnless(hasattr(asyncore, 'file_wrapper'),
                      'asyncore.file_wrapper required')
 class FileWrapperTest(unittest.TestCase):
diff --git a/Lib/test/test_augassign.py b/Lib/test/test_augassign.py
index 9a59c58ec0..19b76874be 100644
--- a/Lib/test/test_augassign.py
+++ b/Lib/test/test_augassign.py
@@ -136,6 +136,14 @@ class AugAssignTest(unittest.TestCase):
                 output.append("__imul__ called")
                 return self
 
+            def __matmul__(self, val):
+                output.append("__matmul__ called")
+            def __rmatmul__(self, val):
+                output.append("__rmatmul__ called")
+            def __imatmul__(self, val):
+                output.append("__imatmul__ called")
+                return self
+
             def __div__(self, val):
                 output.append("__div__ called")
             def __rdiv__(self, val):
@@ -233,6 +241,10 @@ class AugAssignTest(unittest.TestCase):
         1 * x
         x *= 1
 
+        x @ 1
+        1 @ x
+        x @= 1
+
         x / 1
         1 / x
         x /= 1
@@ -279,6 +291,9 @@ __isub__ called
 __mul__ called
 __rmul__ called
 __imul__ called
+__matmul__ called
+__rmatmul__ called
+__imatmul__ called
 __truediv__ called
 __rtruediv__ called
 __itruediv__ called
diff --git a/Lib/test/test_buffer.py b/Lib/test/test_buffer.py
index 1667847a9d..0976fa9e34 100644
--- a/Lib/test/test_buffer.py
+++ b/Lib/test/test_buffer.py
@@ -216,7 +216,7 @@ def iter_format(nitems, testobj='ndarray'):
     for t in iter_mode(nitems, testobj):
         yield t
     if testobj != 'ndarray':
-        raise StopIteration
+        return
     yield struct_items(nitems, testobj)
 
 
@@ -1007,6 +1007,7 @@ class TestBufferProtocol(unittest.TestCase):
         # shape, strides, offset
         structure = (
             ([], [], 0),
+            ([1,3,1], [], 0),
             ([12], [], 0),
             ([12], [-1], 11),
             ([6], [2], 0),
@@ -1078,6 +1079,18 @@ class TestBufferProtocol(unittest.TestCase):
         self.assertRaises(BufferError, ndarray, ex, getbuf=PyBUF_ANY_CONTIGUOUS)
         nd = ndarray(ex, getbuf=PyBUF_SIMPLE)
 
+        # Issue #22445: New precise contiguity definition.
+        for shape in [1,12,1], [7,0,7]:
+            for order in 0, ND_FORTRAN:
+                ex = ndarray(items, shape=shape, flags=order|ND_WRITABLE)
+                self.assertTrue(is_contiguous(ex, 'F'))
+                self.assertTrue(is_contiguous(ex, 'C'))
+
+                for flags in requests:
+                    nd = ndarray(ex, getbuf=flags)
+                    self.assertTrue(is_contiguous(nd, 'F'))
+                    self.assertTrue(is_contiguous(nd, 'C'))
+
     def test_ndarray_exceptions(self):
         nd = ndarray([9], [1])
         ndm = ndarray([9], [1], flags=ND_VAREXPORT)
diff --git a/Lib/test/test_builtin.py b/Lib/test/test_builtin.py
index 14366c652d..6166da563e 100644
--- a/Lib/test/test_builtin.py
+++ b/Lib/test/test_builtin.py
@@ -312,11 +312,11 @@ class BuiltinTest(unittest.TestCase):
         self.assertRaises(TypeError, compile)
         self.assertRaises(ValueError, compile, 'print(42)\n', '<string>', 'badmode')
         self.assertRaises(ValueError, compile, 'print(42)\n', '<string>', 'single', 0xff)
-        self.assertRaises(TypeError, compile, chr(0), 'f', 'exec')
+        self.assertRaises(ValueError, compile, chr(0), 'f', 'exec')
         self.assertRaises(TypeError, compile, 'pass', '?', 'exec',
                           mode='eval', source='0', filename='tmp')
         compile('print("\xe5")\n', '', 'exec')
-        self.assertRaises(TypeError, compile, chr(0), 'f', 'exec')
+        self.assertRaises(ValueError, compile, chr(0), 'f', 'exec')
         self.assertRaises(ValueError, compile, str('a = 1'), 'f', 'bad')
 
         # test the optimize argument
@@ -1094,7 +1094,7 @@ class BuiltinTest(unittest.TestCase):
         self.assertAlmostEqual(pow(-1, 0.5), 1j)
         self.assertAlmostEqual(pow(-1, 1/3), 0.5 + 0.8660254037844386j)
 
-        self.assertRaises(TypeError, pow, -1, -2, 3)
+        self.assertRaises(ValueError, pow, -1, -2, 3)
         self.assertRaises(ValueError, pow, 1, 2, 0)
 
         self.assertRaises(TypeError, pow)
diff --git a/Lib/test/test_bytes.py b/Lib/test/test_bytes.py
index e15807e516..a9f64a0dcc 100644
--- a/Lib/test/test_bytes.py
+++ b/Lib/test/test_bytes.py
@@ -461,6 +461,28 @@ class BaseBytesTest:
         self.assertEqual(b.rindex(i, 3, 9), 7)
         self.assertRaises(ValueError, b.rindex, w, 1, 3)
 
+    def test_mod(self):
+        b = b'hello, %b!'
+        orig = b
+        b = b % b'world'
+        self.assertEqual(b, b'hello, world!')
+        self.assertEqual(orig, b'hello, %b!')
+        self.assertFalse(b is orig)
+        b = b'%s / 100 = %d%%'
+        a = b % (b'seventy-nine', 79)
+        self.assertEqual(a, b'seventy-nine / 100 = 79%')
+
+    def test_imod(self):
+        b = b'hello, %b!'
+        orig = b
+        b %= b'world'
+        self.assertEqual(b, b'hello, world!')
+        self.assertEqual(orig, b'hello, %b!')
+        self.assertFalse(b is orig)
+        b = b'%s / 100 = %d%%'
+        b %= (b'seventy-nine', 79)
+        self.assertEqual(b, b'seventy-nine / 100 = 79%')
+
     def test_replace(self):
         b = self.type2test(b'mississippi')
         self.assertEqual(b.replace(b'i', b'a'), b'massassappa')
@@ -722,6 +744,11 @@ class BaseBytesTest:
 class BytesTest(BaseBytesTest, unittest.TestCase):
     type2test = bytes
 
+    def test_getitem_error(self):
+        msg = "byte indices must be integers or slices"
+        with self.assertRaisesRegex(TypeError, msg):
+            b'python'['a']
+
     def test_buffer_is_readonly(self):
         fd = os.open(__file__, os.O_RDONLY)
         with open(fd, "rb", buffering=0) as f:
@@ -776,6 +803,17 @@ class BytesTest(BaseBytesTest, unittest.TestCase):
 class ByteArrayTest(BaseBytesTest, unittest.TestCase):
     type2test = bytearray
 
+    def test_getitem_error(self):
+        msg = "bytearray indices must be integers or slices"
+        with self.assertRaisesRegex(TypeError, msg):
+            bytearray(b'python')['a']
+
+    def test_setitem_error(self):
+        msg = "bytearray indices must be integers or slices"
+        with self.assertRaisesRegex(TypeError, msg):
+            b = bytearray(b'python')
+            b['a'] = "python"
+
     def test_nohash(self):
         self.assertRaises(TypeError, hash, bytearray())
 
@@ -974,6 +1012,28 @@ class ByteArrayTest(BaseBytesTest, unittest.TestCase):
         b[8:] = b
         self.assertEqual(b, bytearray(list(range(8)) + list(range(256))))
 
+    def test_mod(self):
+        b = bytearray(b'hello, %b!')
+        orig = b
+        b = b % b'world'
+        self.assertEqual(b, b'hello, world!')
+        self.assertEqual(orig, bytearray(b'hello, %b!'))
+        self.assertFalse(b is orig)
+        b = bytearray(b'%s / 100 = %d%%')
+        a = b % (b'seventy-nine', 79)
+        self.assertEqual(a, bytearray(b'seventy-nine / 100 = 79%'))
+
+    def test_imod(self):
+        b = bytearray(b'hello, %b!')
+        orig = b
+        b %= b'world'
+        self.assertEqual(b, b'hello, world!')
+        self.assertEqual(orig, bytearray(b'hello, %b!'))
+        self.assertFalse(b is orig)
+        b = bytearray(b'%s / 100 = %d%%')
+        b %= (b'seventy-nine', 79)
+        self.assertEqual(b, bytearray(b'seventy-nine / 100 = 79%'))
+
     def test_iconcat(self):
         b = bytearray(b"abc")
         b1 = b
@@ -1164,6 +1224,10 @@ class ByteArrayTest(BaseBytesTest, unittest.TestCase):
         self.assertRaises(BufferError, delslice)
         self.assertEqual(b, orig)
 
+    @test.support.cpython_only
+    def test_obsolete_write_lock(self):
+        from _testcapi import getbuffer_with_null_view
+        self.assertRaises(BufferError, getbuffer_with_null_view, bytearray())
 
 class AssortedBytesTest(unittest.TestCase):
     #
diff --git a/Lib/test/test_capi.py b/Lib/test/test_capi.py
index ba7c38db27..de8d65a963 100644
--- a/Lib/test/test_capi.py
+++ b/Lib/test/test_capi.py
@@ -150,6 +150,23 @@ class CAPITest(unittest.TestCase):
         self.assertEqual(_testcapi.docstring_with_signature_and_extra_newlines.__text_signature__,
             "($module, /, parameter)")
 
+    def test_c_type_with_matrix_multiplication(self):
+        M = _testcapi.matmulType
+        m1 = M()
+        m2 = M()
+        self.assertEqual(m1 @ m2, ("matmul", m1, m2))
+        self.assertEqual(m1 @ 42, ("matmul", m1, 42))
+        self.assertEqual(42 @ m1, ("matmul", 42, m1))
+        o = m1
+        o @= m2
+        self.assertEqual(o, ("imatmul", m1, m2))
+        o = m1
+        o @= 42
+        self.assertEqual(o, ("imatmul", m1, 42))
+        o = 42
+        o @= m1
+        self.assertEqual(o, ("matmul", 42, m1))
+
 
 @unittest.skipUnless(threading, 'Threading required for this test.')
 class TestPendingCalls(unittest.TestCase):
@@ -268,7 +285,7 @@ class EmbeddingTests(unittest.TestCase):
             exename += ext
             exepath = os.path.dirname(sys.executable)
         else:
-            exepath = os.path.join(basepath, "Modules")
+            exepath = os.path.join(basepath, "Programs")
         self.test_exe = exe = os.path.join(exepath, exename)
         if not os.path.exists(exe):
             self.skipTest("%r doesn't exist" % exe)
@@ -287,12 +304,13 @@ class EmbeddingTests(unittest.TestCase):
         cmd.extend(args)
         p = subprocess.Popen(cmd,
                              stdout=subprocess.PIPE,
-                             stderr=subprocess.PIPE)
+                             stderr=subprocess.PIPE,
+                             universal_newlines=True)
         (out, err) = p.communicate()
         self.assertEqual(p.returncode, 0,
                          "bad returncode %d, stderr is %r" %
                          (p.returncode, err))
-        return out.decode("latin1"), err.decode("latin1")
+        return out, err
 
     def test_subinterps(self):
         # This is just a "don't crash" test
@@ -319,34 +337,38 @@ class EmbeddingTests(unittest.TestCase):
             print()
             print(out)
             print(err)
+        expected_errors = sys.__stdout__.errors
         expected_stdin_encoding = sys.__stdin__.encoding
         expected_pipe_encoding = self._get_default_pipe_encoding()
-        expected_output = os.linesep.join([
+        expected_output = '\n'.join([
         "--- Use defaults ---",
         "Expected encoding: default",
         "Expected errors: default",
-        "stdin: {0}:strict",
-        "stdout: {1}:strict",
-        "stderr: {1}:backslashreplace",
+        "stdin: {in_encoding}:{errors}",
+        "stdout: {out_encoding}:{errors}",
+        "stderr: {out_encoding}:backslashreplace",
         "--- Set errors only ---",
         "Expected encoding: default",
-        "Expected errors: surrogateescape",
-        "stdin: {0}:surrogateescape",
-        "stdout: {1}:surrogateescape",
-        "stderr: {1}:backslashreplace",
+        "Expected errors: ignore",
+        "stdin: {in_encoding}:ignore",
+        "stdout: {out_encoding}:ignore",
+        "stderr: {out_encoding}:backslashreplace",
         "--- Set encoding only ---",
         "Expected encoding: latin-1",
         "Expected errors: default",
-        "stdin: latin-1:strict",
-        "stdout: latin-1:strict",
+        "stdin: latin-1:{errors}",
+        "stdout: latin-1:{errors}",
         "stderr: latin-1:backslashreplace",
         "--- Set encoding and errors ---",
         "Expected encoding: latin-1",
-        "Expected errors: surrogateescape",
-        "stdin: latin-1:surrogateescape",
-        "stdout: latin-1:surrogateescape",
-        "stderr: latin-1:backslashreplace"]).format(expected_stdin_encoding,
-                                                    expected_pipe_encoding)
+        "Expected errors: replace",
+        "stdin: latin-1:replace",
+        "stdout: latin-1:replace",
+        "stderr: latin-1:backslashreplace"])
+        expected_output = expected_output.format(
+                                in_encoding=expected_stdin_encoding,
+                                out_encoding=expected_pipe_encoding,
+                                errors=expected_errors)
         # This is useful if we ever trip over odd platform behaviour
         self.maxDiff = None
         self.assertEqual(out.strip(), expected_output)
diff --git a/Lib/test/test_cgi.py b/Lib/test/test_cgi.py
index 1127dd12e6..715bd73279 100644
--- a/Lib/test/test_cgi.py
+++ b/Lib/test/test_cgi.py
@@ -1,4 +1,4 @@
-from test.support import run_unittest, check_warnings
+from test.support import check_warnings
 import cgi
 import os
 import sys
@@ -307,6 +307,17 @@ Content-Type: text/plain
                 got = getattr(files[x], k)
                 self.assertEqual(got, exp)
 
+    def test_fieldstorage_as_context_manager(self):
+        fp = BytesIO(b'x' * 10)
+        env = {'REQUEST_METHOD': 'PUT'}
+        with cgi.FieldStorage(fp=fp, environ=env) as fs:
+            content = fs.file.read()
+            self.assertFalse(fs.file.closed)
+        self.assertTrue(fs.file.closed)
+        self.assertEqual(content, 'x' * 10)
+        with self.assertRaisesRegex(ValueError, 'I/O operation on closed file'):
+            fs.file.read()
+
     _qs_result = {
         'key1': 'value1',
         'key2': ['value2x', 'value2y'],
@@ -481,9 +492,5 @@ Content-Transfer-Encoding: binary
 --AaB03x--
 """
 
-
-def test_main():
-    run_unittest(CgiTests)
-
 if __name__ == '__main__':
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_cmd_line.py b/Lib/test/test_cmd_line.py
index 3683a48b7a..ebe557e73c 100644
--- a/Lib/test/test_cmd_line.py
+++ b/Lib/test/test_cmd_line.py
@@ -440,7 +440,7 @@ class CmdLineTest(unittest.TestCase):
         self.assertEqual(err.splitlines().count(b'Unknown option: -a'), 1)
         self.assertEqual(b'', out)
 
-    @unittest.skipIf(script_helper._interpreter_requires_environment(),
+    @unittest.skipIf(script_helper.interpreter_requires_environment(),
                      'Cannot run -I tests when PYTHON env vars are required.')
     def test_isolatedmode(self):
         self.verify_valid_flag('-I')
diff --git a/Lib/test/test_code_module.py b/Lib/test/test_code_module.py
index 7a80a808b1..9b177672b4 100644
--- a/Lib/test/test_code_module.py
+++ b/Lib/test/test_code_module.py
@@ -1,6 +1,7 @@
 "Test InteractiveConsole and InteractiveInterpreter from code module"
 import sys
 import unittest
+from textwrap import dedent
 from contextlib import ExitStack
 from unittest import mock
 from test import support
@@ -78,6 +79,40 @@ class TestInteractiveConsole(unittest.TestCase):
         self.console.interact(banner='')
         self.assertEqual(len(self.stderr.method_calls), 1)
 
+    def test_cause_tb(self):
+        self.infunc.side_effect = ["raise ValueError('') from AttributeError",
+                                    EOFError('Finished')]
+        self.console.interact()
+        output = ''.join(''.join(call[1]) for call in self.stderr.method_calls)
+        expected = dedent("""
+        AttributeError
+
+        The above exception was the direct cause of the following exception:
+
+        Traceback (most recent call last):
+          File "<console>", line 1, in <module>
+        ValueError
+        """)
+        self.assertIn(expected, output)
+
+    def test_context_tb(self):
+        self.infunc.side_effect = ["try: ham\nexcept: eggs\n",
+                                    EOFError('Finished')]
+        self.console.interact()
+        output = ''.join(''.join(call[1]) for call in self.stderr.method_calls)
+        expected = dedent("""
+        Traceback (most recent call last):
+          File "<console>", line 1, in <module>
+        NameError: name 'ham' is not defined
+
+        During handling of the above exception, another exception occurred:
+
+        Traceback (most recent call last):
+          File "<console>", line 2, in <module>
+        NameError: name 'eggs' is not defined
+        """)
+        self.assertIn(expected, output)
+
 
 def test_main():
     support.run_unittest(TestInteractiveConsole)
diff --git a/Lib/test/test_codeccallbacks.py b/Lib/test/test_codeccallbacks.py
index 84804bb0da..e29ac53039 100644
--- a/Lib/test/test_codeccallbacks.py
+++ b/Lib/test/test_codeccallbacks.py
@@ -158,6 +158,22 @@ class CodecCallbackTest(unittest.TestCase):
         sout = b"a\xac\\u1234\xa4\\u8000\\U0010ffff"
         self.assertEqual(sin.encode("iso-8859-15", "backslashreplace"), sout)
 
+    def test_nameescape(self):
+        # Does the same as backslashescape, but prefers ``\N{...}`` escape
+        # sequences.
+        sin = "a\xac\u1234\u20ac\u8000\U0010ffff"
+        sout = (b'a\\N{NOT SIGN}\\N{ETHIOPIC SYLLABLE SEE}\\N{EURO SIGN}'
+                b'\\N{CJK UNIFIED IDEOGRAPH-8000}\\U0010ffff')
+        self.assertEqual(sin.encode("ascii", "namereplace"), sout)
+
+        sout = (b'a\xac\\N{ETHIOPIC SYLLABLE SEE}\\N{EURO SIGN}'
+                b'\\N{CJK UNIFIED IDEOGRAPH-8000}\\U0010ffff')
+        self.assertEqual(sin.encode("latin-1", "namereplace"), sout)
+
+        sout = (b'a\xac\\N{ETHIOPIC SYLLABLE SEE}\xa4'
+                b'\\N{CJK UNIFIED IDEOGRAPH-8000}\\U0010ffff')
+        self.assertEqual(sin.encode("iso-8859-15", "namereplace"), sout)
+
     def test_decoding_callbacks(self):
         # This is a test for a decoding callback handler
         # that allows the decoding of the invalid sequence
@@ -230,6 +246,11 @@ class CodecCallbackTest(unittest.TestCase):
                     "\u0000\ufffd"
                 )
 
+                self.assertEqual(
+                    b"\x00\x00\x00\x00\x00".decode("unicode-internal", "backslashreplace"),
+                    "\u0000\\x00"
+                )
+
                 codecs.register_error("test.hui", handler_unicodeinternal)
 
                 self.assertEqual(
@@ -297,7 +318,7 @@ class CodecCallbackTest(unittest.TestCase):
     def test_longstrings(self):
         # test long strings to check for memory overflow problems
         errors = [ "strict", "ignore", "replace", "xmlcharrefreplace",
-                   "backslashreplace"]
+                   "backslashreplace", "namereplace"]
         # register the handlers under different names,
         # to prevent the codec from recognizing the name
         for err in errors:
@@ -549,17 +570,6 @@ class CodecCallbackTest(unittest.TestCase):
            codecs.backslashreplace_errors,
            UnicodeError("ouch")
         )
-        # "backslashreplace" can only be used for encoding
-        self.assertRaises(
-            TypeError,
-            codecs.backslashreplace_errors,
-            UnicodeDecodeError("ascii", bytearray(b"\xff"), 0, 1, "ouch")
-        )
-        self.assertRaises(
-            TypeError,
-            codecs.backslashreplace_errors,
-            UnicodeTranslateError("\u3042", 0, 1, "ouch")
-        )
         # Use the correct exception
         self.assertEqual(
             codecs.backslashreplace_errors(
@@ -611,6 +621,91 @@ class CodecCallbackTest(unittest.TestCase):
                 ("\\udfff", 1)
             )
 
+    def test_badandgoodnamereplaceexceptions(self):
+        # "namereplace" complains about a non-exception passed in
+        self.assertRaises(
+           TypeError,
+           codecs.namereplace_errors,
+           42
+        )
+        # "namereplace" complains about the wrong exception types
+        self.assertRaises(
+           TypeError,
+           codecs.namereplace_errors,
+           UnicodeError("ouch")
+        )
+        # "namereplace" can only be used for encoding
+        self.assertRaises(
+            TypeError,
+            codecs.namereplace_errors,
+            UnicodeDecodeError("ascii", bytearray(b"\xff"), 0, 1, "ouch")
+        )
+        self.assertRaises(
+            TypeError,
+            codecs.namereplace_errors,
+            UnicodeTranslateError("\u3042", 0, 1, "ouch")
+        )
+        # Use the correct exception
+        self.assertEqual(
+            codecs.namereplace_errors(
+                UnicodeEncodeError("ascii", "\u3042", 0, 1, "ouch")),
+            ("\\N{HIRAGANA LETTER A}", 1)
+        )
+        self.assertEqual(
+            codecs.namereplace_errors(
+                UnicodeEncodeError("ascii", "\x00", 0, 1, "ouch")),
+            ("\\x00", 1)
+        )
+        self.assertEqual(
+            codecs.namereplace_errors(
+                UnicodeEncodeError("ascii", "\xff", 0, 1, "ouch")),
+            ("\\N{LATIN SMALL LETTER Y WITH DIAERESIS}", 1)
+        )
+        self.assertEqual(
+            codecs.namereplace_errors(
+                UnicodeEncodeError("ascii", "\u0100", 0, 1, "ouch")),
+            ("\\N{LATIN CAPITAL LETTER A WITH MACRON}", 1)
+        )
+        self.assertEqual(
+            codecs.namereplace_errors(
+                UnicodeEncodeError("ascii", "\uffff", 0, 1, "ouch")),
+            ("\\uffff", 1)
+        )
+        if SIZEOF_WCHAR_T > 0:
+            self.assertEqual(
+                codecs.namereplace_errors(
+                    UnicodeEncodeError("ascii", "\U00010000",
+                                       0, 1, "ouch")),
+                ("\\N{LINEAR B SYLLABLE B008 A}", 1)
+            )
+            self.assertEqual(
+                codecs.namereplace_errors(
+                    UnicodeEncodeError("ascii", "\U0010ffff",
+                                       0, 1, "ouch")),
+                ("\\U0010ffff", 1)
+            )
+            # Lone surrogates (regardless of unicode width)
+            self.assertEqual(
+                codecs.namereplace_errors(
+                    UnicodeEncodeError("ascii", "\ud800", 0, 1, "ouch")),
+                ("\\ud800", 1)
+            )
+            self.assertEqual(
+                codecs.namereplace_errors(
+                    UnicodeEncodeError("ascii", "\udfff", 0, 1, "ouch")),
+                ("\\udfff", 1)
+            )
+        self.assertEqual(
+            codecs.backslashreplace_errors(
+                UnicodeDecodeError("ascii", bytearray(b"\xff"), 0, 1, "ouch")),
+            ("\\xff", 1)
+        )
+        self.assertEqual(
+            codecs.backslashreplace_errors(
+                UnicodeTranslateError("\u3042", 0, 1, "ouch")),
+            ("\\u3042", 1)
+        )
+
     def test_badhandlerresults(self):
         results = ( 42, "foo", (1,2,3), ("foo", 1, 3), ("foo", None), ("foo",), ("foo", 1, 3), ("foo", None), ("foo",) )
         encs = ("ascii", "latin-1", "iso-8859-1", "iso-8859-15")
@@ -651,6 +746,10 @@ class CodecCallbackTest(unittest.TestCase):
             codecs.backslashreplace_errors,
             codecs.lookup_error("backslashreplace")
         )
+        self.assertEqual(
+            codecs.namereplace_errors,
+            codecs.lookup_error("namereplace")
+        )
 
     def test_unencodablereplacement(self):
         def unencrepl(exc):
@@ -804,7 +903,8 @@ class CodecCallbackTest(unittest.TestCase):
         class D(dict):
             def __getitem__(self, key):
                 raise ValueError
-        for err in ("strict", "replace", "xmlcharrefreplace", "backslashreplace", "test.posreturn"):
+        for err in ("strict", "replace", "xmlcharrefreplace",
+                    "backslashreplace", "namereplace", "test.posreturn"):
             self.assertRaises(UnicodeError, codecs.charmap_encode, "\xff", err, {0xff: None})
             self.assertRaises(ValueError, codecs.charmap_encode, "\xff", err, D())
             self.assertRaises(TypeError, codecs.charmap_encode, "\xff", err, {0xff: 300})
@@ -819,7 +919,7 @@ class CodecCallbackTest(unittest.TestCase):
             def __getitem__(self, key):
                 raise ValueError
         #self.assertRaises(ValueError, "\xff".translate, D())
-        self.assertRaises(TypeError, "\xff".translate, {0xff: sys.maxunicode+1})
+        self.assertRaises(ValueError, "\xff".translate, {0xff: sys.maxunicode+1})
         self.assertRaises(TypeError, "\xff".translate, {0xff: ()})
 
     def test_bug828737(self):
diff --git a/Lib/test/test_codecs.py b/Lib/test/test_codecs.py
index 6629ccd4e2..4d5d7bbba8 100644
--- a/Lib/test/test_codecs.py
+++ b/Lib/test/test_codecs.py
@@ -349,6 +349,8 @@ class ReadTest(MixInCheckStateHandling):
         self.assertRaises(UnicodeEncodeError, "\ud800".encode, self.encoding)
         self.assertEqual("[\uDC80]".encode(self.encoding, "backslashreplace"),
                          "[\\udc80]".encode(self.encoding))
+        self.assertEqual("[\uDC80]".encode(self.encoding, "namereplace"),
+                         "[\\udc80]".encode(self.encoding))
         self.assertEqual("[\uDC80]".encode(self.encoding, "xmlcharrefreplace"),
                          "[&#56448;]".encode(self.encoding))
         self.assertEqual("[\uDC80]".encode(self.encoding, "ignore"),
@@ -376,6 +378,10 @@ class ReadTest(MixInCheckStateHandling):
                              before + after)
             self.assertEqual(test_sequence.decode(self.encoding, "replace"),
                              before + self.ill_formed_sequence_replace + after)
+            backslashreplace = ''.join('\\x%02x' % b
+                                       for b in self.ill_formed_sequence)
+            self.assertEqual(test_sequence.decode(self.encoding, "backslashreplace"),
+                             before + backslashreplace + after)
 
 class UTF32Test(ReadTest, unittest.TestCase):
     encoding = "utf-32"
@@ -808,6 +814,7 @@ class CP65001Test(ReadTest, unittest.TestCase):
                 ('\udc80', 'ignore', b''),
                 ('\udc80', 'replace', b'?'),
                 ('\udc80', 'backslashreplace', b'\\udc80'),
+                ('\udc80', 'namereplace', b'\\udc80'),
                 ('\udc80', 'surrogatepass', b'\xed\xb2\x80'),
             ))
         else:
@@ -869,6 +876,8 @@ class CP65001Test(ReadTest, unittest.TestCase):
         self.assertRaises(UnicodeDecodeError, b"\xed\xa0\x80".decode, "cp65001")
         self.assertEqual("[\uDC80]".encode("cp65001", "backslashreplace"),
                          b'[\\udc80]')
+        self.assertEqual("[\uDC80]".encode("cp65001", "namereplace"),
+                         b'[\\udc80]')
         self.assertEqual("[\uDC80]".encode("cp65001", "xmlcharrefreplace"),
                          b'[&#56448;]')
         self.assertEqual("[\uDC80]".encode("cp65001", "surrogateescape"),
@@ -890,10 +899,6 @@ class CP65001Test(ReadTest, unittest.TestCase):
                          "\U00010fff\uD800")
         self.assertTrue(codecs.lookup_error("surrogatepass"))
 
-    def test_readline(self):
-        self.skipTest("issue #20571: code page 65001 codec does not "
-                      "support partial decoder yet")
-
 
 class UTF7Test(ReadTest, unittest.TestCase):
     encoding = "utf-7"
@@ -1299,14 +1304,19 @@ class UnicodeInternalTest(unittest.TestCase):
                                   "unicode_internal")
         if sys.byteorder == "little":
             invalid = b"\x00\x00\x11\x00"
+            invalid_backslashreplace = r"\x00\x00\x11\x00"
         else:
             invalid = b"\x00\x11\x00\x00"
+            invalid_backslashreplace = r"\x00\x11\x00\x00"
         with support.check_warnings():
             self.assertRaises(UnicodeDecodeError,
                               invalid.decode, "unicode_internal")
         with support.check_warnings():
             self.assertEqual(invalid.decode("unicode_internal", "replace"),
                              '\ufffd')
+        with support.check_warnings():
+            self.assertEqual(invalid.decode("unicode_internal", "backslashreplace"),
+                             invalid_backslashreplace)
 
     @unittest.skipUnless(SIZEOF_WCHAR_T == 4, 'specific to 32-bit wchar_t')
     def test_decode_error_attributes(self):
@@ -1612,6 +1622,12 @@ class CodecsModuleTest(unittest.TestCase):
         self.assertEqual(codecs.decode(b'abc'), 'abc')
         self.assertRaises(UnicodeDecodeError, codecs.decode, b'\xff', 'ascii')
 
+        # test keywords
+        self.assertEqual(codecs.decode(obj=b'\xe4\xf6\xfc', encoding='latin-1'),
+                         '\xe4\xf6\xfc')
+        self.assertEqual(codecs.decode(b'[\xff]', 'ascii', errors='ignore'),
+                         '[]')
+
     def test_encode(self):
         self.assertEqual(codecs.encode('\xe4\xf6\xfc', 'latin-1'),
                          b'\xe4\xf6\xfc')
@@ -1620,6 +1636,12 @@ class CodecsModuleTest(unittest.TestCase):
         self.assertEqual(codecs.encode('abc'), b'abc')
         self.assertRaises(UnicodeEncodeError, codecs.encode, '\xffff', 'ascii')
 
+        # test keywords
+        self.assertEqual(codecs.encode(obj='\xe4\xf6\xfc', encoding='latin-1'),
+                         b'\xe4\xf6\xfc')
+        self.assertEqual(codecs.encode('[\xff]', 'ascii', errors='ignore'),
+                         b'[]')
+
     def test_register(self):
         self.assertRaises(TypeError, codecs.register)
         self.assertRaises(TypeError, codecs.register, 42)
@@ -1668,6 +1690,7 @@ class CodecsModuleTest(unittest.TestCase):
             "register_error", "lookup_error",
             "strict_errors", "replace_errors", "ignore_errors",
             "xmlcharrefreplace_errors", "backslashreplace_errors",
+            "namereplace_errors",
             "open", "EncodedFile",
             "iterencode", "iterdecode",
             "BOM", "BOM_BE", "BOM_LE",
@@ -2029,6 +2052,16 @@ class CharmapTest(unittest.TestCase):
         )
 
         self.assertEqual(
+            codecs.charmap_decode(b"\x00\x01\x02", "backslashreplace", "ab"),
+            ("ab\\x02", 3)
+        )
+
+        self.assertEqual(
+            codecs.charmap_decode(b"\x00\x01\x02", "backslashreplace", "ab\ufffe"),
+            ("ab\\x02", 3)
+        )
+
+        self.assertEqual(
             codecs.charmap_decode(b"\x00\x01\x02", "ignore", "ab"),
             ("ab", 3)
         )
@@ -2105,6 +2138,25 @@ class CharmapTest(unittest.TestCase):
         )
 
         self.assertEqual(
+            codecs.charmap_decode(b"\x00\x01\x02", "backslashreplace",
+                                  {0: 'a', 1: 'b'}),
+            ("ab\\x02", 3)
+        )
+
+        self.assertEqual(
+            codecs.charmap_decode(b"\x00\x01\x02", "backslashreplace",
+                                  {0: 'a', 1: 'b', 2: None}),
+            ("ab\\x02", 3)
+        )
+
+        # Issue #14850
+        self.assertEqual(
+            codecs.charmap_decode(b"\x00\x01\x02", "backslashreplace",
+                                  {0: 'a', 1: 'b', 2: '\ufffe'}),
+            ("ab\\x02", 3)
+        )
+
+        self.assertEqual(
             codecs.charmap_decode(b"\x00\x01\x02", "ignore",
                                   {0: 'a', 1: 'b'}),
             ("ab", 3)
@@ -2181,6 +2233,18 @@ class CharmapTest(unittest.TestCase):
         )
 
         self.assertEqual(
+            codecs.charmap_decode(b"\x00\x01\x02", "backslashreplace",
+                                  {0: a, 1: b}),
+            ("ab\\x02", 3)
+        )
+
+        self.assertEqual(
+            codecs.charmap_decode(b"\x00\x01\x02", "backslashreplace",
+                                  {0: a, 1: b, 2: 0xFFFE}),
+            ("ab\\x02", 3)
+        )
+
+        self.assertEqual(
             codecs.charmap_decode(b"\x00\x01\x02", "ignore",
                                   {0: a, 1: b}),
             ("ab", 3)
@@ -2239,9 +2303,13 @@ class TypesTest(unittest.TestCase):
 
         self.assertRaises(UnicodeDecodeError, codecs.unicode_escape_decode, br"\U00110000")
         self.assertEqual(codecs.unicode_escape_decode(r"\U00110000", "replace"), ("\ufffd", 10))
+        self.assertEqual(codecs.unicode_escape_decode(r"\U00110000", "backslashreplace"),
+                         (r"\x5c\x55\x30\x30\x31\x31\x30\x30\x30\x30", 10))
 
         self.assertRaises(UnicodeDecodeError, codecs.raw_unicode_escape_decode, br"\U00110000")
         self.assertEqual(codecs.raw_unicode_escape_decode(r"\U00110000", "replace"), ("\ufffd", 10))
+        self.assertEqual(codecs.raw_unicode_escape_decode(r"\U00110000", "backslashreplace"),
+                         (r"\x5c\x55\x30\x30\x31\x31\x30\x30\x30\x30", 10))
 
 
 class UnicodeEscapeTest(unittest.TestCase):
@@ -2818,15 +2886,15 @@ class CodePageTest(unittest.TestCase):
         self.assertRaisesRegex(UnicodeEncodeError, 'cp932',
             codecs.code_page_encode, 932, '\xff')
         self.assertRaisesRegex(UnicodeDecodeError, 'cp932',
-            codecs.code_page_decode, 932, b'\x81\x00')
+            codecs.code_page_decode, 932, b'\x81\x00', 'strict', True)
         self.assertRaisesRegex(UnicodeDecodeError, 'CP_UTF8',
-            codecs.code_page_decode, self.CP_UTF8, b'\xff')
+            codecs.code_page_decode, self.CP_UTF8, b'\xff', 'strict', True)
 
     def check_decode(self, cp, tests):
         for raw, errors, expected in tests:
             if expected is not None:
                 try:
-                    decoded = codecs.code_page_decode(cp, raw, errors)
+                    decoded = codecs.code_page_decode(cp, raw, errors, True)
                 except UnicodeDecodeError as err:
                     self.fail('Unable to decode %a from "cp%s" with '
                               'errors=%r: %s' % (raw, cp, errors, err))
@@ -2838,7 +2906,7 @@ class CodePageTest(unittest.TestCase):
                 self.assertLessEqual(decoded[1], len(raw))
             else:
                 self.assertRaises(UnicodeDecodeError,
-                    codecs.code_page_decode, cp, raw, errors)
+                    codecs.code_page_decode, cp, raw, errors, True)
 
     def check_encode(self, cp, tests):
         for text, errors, expected in tests:
@@ -2866,7 +2934,12 @@ class CodePageTest(unittest.TestCase):
             ('[\xff]', 'replace', b'[y]'),
             ('[\u20ac]', 'replace', b'[?]'),
             ('[\xff]', 'backslashreplace', b'[\\xff]'),
+            ('[\xff]', 'namereplace',
+             b'[\\N{LATIN SMALL LETTER Y WITH DIAERESIS}]'),
             ('[\xff]', 'xmlcharrefreplace', b'[&#255;]'),
+            ('\udcff', 'strict', None),
+            ('[\udcff]', 'surrogateescape', b'[\xff]'),
+            ('[\udcff]', 'surrogatepass', None),
         ))
         self.check_decode(932, (
             (b'abc', 'strict', 'abc'),
@@ -2875,10 +2948,13 @@ class CodePageTest(unittest.TestCase):
             (b'[\xff]', 'strict', None),
             (b'[\xff]', 'ignore', '[]'),
             (b'[\xff]', 'replace', '[\ufffd]'),
+            (b'[\xff]', 'backslashreplace', '[\\xff]'),
             (b'[\xff]', 'surrogateescape', '[\udcff]'),
+            (b'[\xff]', 'surrogatepass', None),
             (b'\x81\x00abc', 'strict', None),
             (b'\x81\x00abc', 'ignore', '\x00abc'),
             (b'\x81\x00abc', 'replace', '\ufffd\x00abc'),
+            (b'\x81\x00abc', 'backslashreplace', '\\x81\x00abc'),
         ))
 
     def test_cp1252(self):
@@ -2886,9 +2962,12 @@ class CodePageTest(unittest.TestCase):
             ('abc', 'strict', b'abc'),
             ('\xe9\u20ac', 'strict',  b'\xe9\x80'),
             ('\xff', 'strict', b'\xff'),
+            # test error handlers
             ('\u0141', 'strict', None),
             ('\u0141', 'ignore', b''),
             ('\u0141', 'replace', b'L'),
+            ('\udc98', 'surrogateescape', b'\x98'),
+            ('\udc98', 'surrogatepass', None),
         ))
         self.check_decode(1252, (
             (b'abc', 'strict', 'abc'),
diff --git a/Lib/test/test_collections.py b/Lib/test/test_collections.py
index df1c63c833..a94b5da860 100644
--- a/Lib/test/test_collections.py
+++ b/Lib/test/test_collections.py
@@ -518,7 +518,7 @@ class TestOneTrickPonyABCs(ABCTestCase):
         class NextOnly:
             def __next__(self):
                 yield 1
-                raise StopIteration
+                return
         self.assertNotIsInstance(NextOnly(), Iterator)
 
     def test_Sized(self):
@@ -647,6 +647,59 @@ class TestCollectionABCs(ABCTestCase):
         a, b = OneTwoThreeSet(), OneTwoThreeSet()
         self.assertTrue(hash(a) == hash(b))
 
+    def test_isdisjoint_Set(self):
+        class MySet(Set):
+            def __init__(self, itr):
+                self.contents = itr
+            def __contains__(self, x):
+                return x in self.contents
+            def __iter__(self):
+                return iter(self.contents)
+            def __len__(self):
+                return len([x for x in self.contents])
+        s1 = MySet((1, 2, 3))
+        s2 = MySet((4, 5, 6))
+        s3 = MySet((1, 5, 6))
+        self.assertTrue(s1.isdisjoint(s2))
+        self.assertFalse(s1.isdisjoint(s3))
+
+    def test_equality_Set(self):
+        class MySet(Set):
+            def __init__(self, itr):
+                self.contents = itr
+            def __contains__(self, x):
+                return x in self.contents
+            def __iter__(self):
+                return iter(self.contents)
+            def __len__(self):
+                return len([x for x in self.contents])
+        s1 = MySet((1,))
+        s2 = MySet((1, 2))
+        s3 = MySet((3, 4))
+        s4 = MySet((3, 4))
+        self.assertTrue(s2 > s1)
+        self.assertTrue(s1 < s2)
+        self.assertFalse(s2 <= s1)
+        self.assertFalse(s2 <= s3)
+        self.assertFalse(s1 >= s2)
+        self.assertEqual(s3, s4)
+        self.assertNotEqual(s2, s3)
+
+    def test_arithmetic_Set(self):
+        class MySet(Set):
+            def __init__(self, itr):
+                self.contents = itr
+            def __contains__(self, x):
+                return x in self.contents
+            def __iter__(self):
+                return iter(self.contents)
+            def __len__(self):
+                return len([x for x in self.contents])
+        s1 = MySet((1, 2, 3))
+        s2 = MySet((3, 4, 5))
+        s3 = s1 & s2
+        self.assertEqual(s3, MySet((3,)))
+
     def test_MutableSet(self):
         self.assertIsInstance(set(), MutableSet)
         self.assertTrue(issubclass(set, MutableSet))
@@ -1378,6 +1431,21 @@ class TestOrderedDict(unittest.TestCase):
         self.assertEqual(list(od.items()), pairs)
         self.assertEqual(list(reversed(od)),
                          [t[0] for t in reversed(pairs)])
+        self.assertEqual(list(reversed(od.keys())),
+                         [t[0] for t in reversed(pairs)])
+        self.assertEqual(list(reversed(od.values())),
+                         [t[1] for t in reversed(pairs)])
+        self.assertEqual(list(reversed(od.items())), list(reversed(pairs)))
+
+    def test_detect_deletion_during_iteration(self):
+        od = OrderedDict.fromkeys('abc')
+        it = iter(od)
+        key = next(it)
+        del od[key]
+        with self.assertRaises(Exception):
+            # Note, the exact exception raised is not guaranteed
+            # The only guarantee that the next() will not succeed
+            next(it)
 
     def test_popitem(self):
         pairs = [('c', 1), ('b', 2), ('a', 3), ('d', 4), ('e', 5), ('f', 6)]
diff --git a/Lib/test/test_compileall.py b/Lib/test/test_compileall.py
index 2a42238755..7506c7018b 100644
--- a/Lib/test/test_compileall.py
+++ b/Lib/test/test_compileall.py
@@ -10,6 +10,13 @@ import time
 import unittest
 import io
 
+from unittest import mock, skipUnless
+try:
+    from concurrent.futures import ProcessPoolExecutor
+    _have_multiprocessing = True
+except ImportError:
+    _have_multiprocessing = False
+
 from test import support, script_helper
 
 class CompileallTests(unittest.TestCase):
@@ -106,6 +113,33 @@ class CompileallTests(unittest.TestCase):
                                                    debug_override=not optimize)
         self.assertTrue(os.path.isfile(cached3))
 
+    @mock.patch('compileall.ProcessPoolExecutor')
+    def test_compile_pool_called(self, pool_mock):
+        compileall.compile_dir(self.directory, quiet=True, workers=5)
+        self.assertTrue(pool_mock.called)
+
+    def test_compile_workers_non_positive(self):
+        with self.assertRaisesRegex(ValueError,
+                                    "workers must be greater or equal to 0"):
+            compileall.compile_dir(self.directory, workers=-1)
+
+    @mock.patch('compileall.ProcessPoolExecutor')
+    def test_compile_workers_cpu_count(self, pool_mock):
+        compileall.compile_dir(self.directory, quiet=True, workers=0)
+        self.assertEqual(pool_mock.call_args[1]['max_workers'], None)
+
+    @mock.patch('compileall.ProcessPoolExecutor')
+    @mock.patch('compileall.compile_file')
+    def test_compile_one_worker(self, compile_file_mock, pool_mock):
+        compileall.compile_dir(self.directory, quiet=True)
+        self.assertFalse(pool_mock.called)
+        self.assertTrue(compile_file_mock.called)
+
+    @mock.patch('compileall.ProcessPoolExecutor', new=None)
+    def test_compile_missing_multiprocessing(self):
+        with self.assertRaisesRegex(NotImplementedError,
+                                    "multiprocessing support not available"):
+            compileall.compile_dir(self.directory, quiet=True, workers=5)
 
 class EncodingTest(unittest.TestCase):
     """Issue 6716: compileall should escape source code when printing errors
@@ -273,12 +307,53 @@ class CommandLineTests(unittest.TestCase):
         self.assertCompiled(subinitfn)
         self.assertCompiled(hamfn)
 
+    def test_recursion_limit(self):
+        subpackage = os.path.join(self.pkgdir, 'spam')
+        subpackage2 = os.path.join(subpackage, 'ham')
+        subpackage3 = os.path.join(subpackage2, 'eggs')
+        for pkg in (subpackage, subpackage2, subpackage3):
+            script_helper.make_pkg(pkg)
+
+        subinitfn = os.path.join(subpackage, '__init__.py')
+        hamfn = script_helper.make_script(subpackage, 'ham', '')
+        spamfn = script_helper.make_script(subpackage2, 'spam', '')
+        eggfn = script_helper.make_script(subpackage3, 'egg', '')
+
+        self.assertRunOK('-q', '-r 0', self.pkgdir)
+        self.assertNotCompiled(subinitfn)
+        self.assertFalse(
+            os.path.exists(os.path.join(subpackage, '__pycache__')))
+
+        self.assertRunOK('-q', '-r 1', self.pkgdir)
+        self.assertCompiled(subinitfn)
+        self.assertCompiled(hamfn)
+        self.assertNotCompiled(spamfn)
+
+        self.assertRunOK('-q', '-r 2', self.pkgdir)
+        self.assertCompiled(subinitfn)
+        self.assertCompiled(hamfn)
+        self.assertCompiled(spamfn)
+        self.assertNotCompiled(eggfn)
+
+        self.assertRunOK('-q', '-r 5', self.pkgdir)
+        self.assertCompiled(subinitfn)
+        self.assertCompiled(hamfn)
+        self.assertCompiled(spamfn)
+        self.assertCompiled(eggfn)
+
     def test_quiet(self):
         noisy = self.assertRunOK(self.pkgdir)
         quiet = self.assertRunOK('-q', self.pkgdir)
         self.assertNotEqual(b'', noisy)
         self.assertEqual(b'', quiet)
 
+    def test_silent(self):
+        script_helper.make_script(self.pkgdir, 'crunchyfrog', 'bad(syntax')
+        _, quiet, _ = self.assertRunNotOK('-q', self.pkgdir)
+        _, silent, _ = self.assertRunNotOK('-qq', self.pkgdir)
+        self.assertNotEqual(b'', quiet)
+        self.assertEqual(b'', silent)
+
     def test_regexp(self):
         self.assertRunOK('-q', '-x', r'ba[^\\/]*$', self.pkgdir)
         self.assertNotCompiled(self.barfn)
@@ -379,6 +454,29 @@ class CommandLineTests(unittest.TestCase):
         out = self.assertRunOK('badfilename')
         self.assertRegex(out, b"Can't list 'badfilename'")
 
+    @skipUnless(_have_multiprocessing, "requires multiprocessing")
+    def test_workers(self):
+        bar2fn = script_helper.make_script(self.directory, 'bar2', '')
+        files = []
+        for suffix in range(5):
+            pkgdir = os.path.join(self.directory, 'foo{}'.format(suffix))
+            os.mkdir(pkgdir)
+            fn = script_helper.make_script(pkgdir, '__init__', '')
+            files.append(script_helper.make_script(pkgdir, 'bar2', ''))
+
+        self.assertRunOK(self.directory, '-j', '0')
+        self.assertCompiled(bar2fn)
+        for file in files:
+            self.assertCompiled(file)
+
+    @mock.patch('compileall.compile_dir')
+    def test_workers_available_cores(self, compile_dir):
+        with mock.patch("sys.argv",
+                        new=[sys.executable, self.directory, "-j0"]):
+            compileall.main()
+            self.assertTrue(compile_dir.called)
+            self.assertEqual(compile_dir.call_args[-1]['workers'], None)
+
 
 if __name__ == "__main__":
     unittest.main()
diff --git a/Lib/test/test_concurrent_futures.py b/Lib/test/test_concurrent_futures.py
index c74b2ca6ed..86802c2d56 100644
--- a/Lib/test/test_concurrent_futures.py
+++ b/Lib/test/test_concurrent_futures.py
@@ -11,6 +11,7 @@ test.support.import_module('threading')
 
 from test.script_helper import assert_python_ok
 
+import os
 import sys
 import threading
 import time
@@ -425,6 +426,13 @@ class ExecutorTest:
         self.assertTrue(collected,
                         "Stale reference not collected within timeout.")
 
+    def test_max_workers_negative(self):
+        for number in (0, -1):
+            with self.assertRaisesRegex(ValueError,
+                                        "max_workers must be greater "
+                                        "than 0"):
+                self.executor_type(max_workers=number)
+
 
 class ThreadPoolExecutorTest(ThreadPoolMixin, ExecutorTest, unittest.TestCase):
     def test_map_submits_without_iteration(self):
@@ -437,6 +445,11 @@ class ThreadPoolExecutorTest(ThreadPoolMixin, ExecutorTest, unittest.TestCase):
         self.executor.shutdown(wait=True)
         self.assertCountEqual(finished, range(10))
 
+    def test_default_workers(self):
+        executor = self.executor_type()
+        self.assertEqual(executor._max_workers,
+                         (os.cpu_count() or 1) * 5)
+
 
 class ProcessPoolExecutorTest(ProcessPoolMixin, ExecutorTest, unittest.TestCase):
     def test_killed_child(self):
@@ -451,6 +464,48 @@ class ProcessPoolExecutorTest(ProcessPoolMixin, ExecutorTest, unittest.TestCase)
         # Submitting other jobs fails as well.
         self.assertRaises(BrokenProcessPool, self.executor.submit, pow, 2, 8)
 
+    def test_map_chunksize(self):
+        def bad_map():
+            list(self.executor.map(pow, range(40), range(40), chunksize=-1))
+
+        ref = list(map(pow, range(40), range(40)))
+        self.assertEqual(
+            list(self.executor.map(pow, range(40), range(40), chunksize=6)),
+            ref)
+        self.assertEqual(
+            list(self.executor.map(pow, range(40), range(40), chunksize=50)),
+            ref)
+        self.assertEqual(
+            list(self.executor.map(pow, range(40), range(40), chunksize=40)),
+            ref)
+        self.assertRaises(ValueError, bad_map)
+
+    @classmethod
+    def _test_traceback(cls):
+        raise RuntimeError(123) # some comment
+
+    def test_traceback(self):
+        # We want ensure that the traceback from the child process is
+        # contained in the traceback raised in the main process.
+        future = self.executor.submit(self._test_traceback)
+        with self.assertRaises(Exception) as cm:
+            future.result()
+
+        exc = cm.exception
+        self.assertIs(type(exc), RuntimeError)
+        self.assertEqual(exc.args, (123,))
+        cause = exc.__cause__
+        self.assertIs(type(cause), futures.process._RemoteTraceback)
+        self.assertIn('raise RuntimeError(123) # some comment', cause.tb)
+
+        with test.support.captured_stderr() as f1:
+            try:
+                raise exc
+            except RuntimeError:
+                sys.excepthook(*sys.exc_info())
+        self.assertIn('raise RuntimeError(123) # some comment',
+                      f1.getvalue())
+
 
 class FutureTests(unittest.TestCase):
     def test_done_callback_with_result(self):
diff --git a/Lib/test/test_configparser.py b/Lib/test/test_configparser.py
index 09c229a612..470d2cd1f3 100644
--- a/Lib/test/test_configparser.py
+++ b/Lib/test/test_configparser.py
@@ -579,7 +579,7 @@ boolean {0[0]} NO
             return e
         else:
             self.fail("expected exception type %s.%s"
-                      % (exc.__module__, exc.__name__))
+                      % (exc.__module__, exc.__qualname__))
 
     def test_boolean(self):
         cf = self.fromstring(
@@ -1584,6 +1584,34 @@ class CoverageOneHundredTestCase(unittest.TestCase):
         """)
         self.assertEqual(repr(parser['section']), '<Section: section>')
 
+    def test_inconsistent_converters_state(self):
+        parser = configparser.ConfigParser()
+        import decimal
+        parser.converters['decimal'] = decimal.Decimal
+        parser.read_string("""
+            [s1]
+            one = 1
+            [s2]
+            two = 2
+        """)
+        self.assertIn('decimal', parser.converters)
+        self.assertEqual(parser.getdecimal('s1', 'one'), 1)
+        self.assertEqual(parser.getdecimal('s2', 'two'), 2)
+        self.assertEqual(parser['s1'].getdecimal('one'), 1)
+        self.assertEqual(parser['s2'].getdecimal('two'), 2)
+        del parser.getdecimal
+        with self.assertRaises(AttributeError):
+            parser.getdecimal('s1', 'one')
+        self.assertIn('decimal', parser.converters)
+        del parser.converters['decimal']
+        self.assertNotIn('decimal', parser.converters)
+        with self.assertRaises(AttributeError):
+            parser.getdecimal('s1', 'one')
+        with self.assertRaises(AttributeError):
+            parser['s1'].getdecimal('one')
+        with self.assertRaises(AttributeError):
+            parser['s2'].getdecimal('two')
+
 
 class ExceptionPicklingTestCase(unittest.TestCase):
     """Tests for issue #13760: ConfigParser exceptions are not picklable."""
@@ -1776,5 +1804,252 @@ class InlineCommentStrippingTestCase(unittest.TestCase):
         self.assertEqual(s['k3'], 'v3;#//still v3# and still v3')
 
 
+class ExceptionContextTestCase(unittest.TestCase):
+    """ Test that implementation details doesn't leak
+    through raising exceptions. """
+
+    def test_get_basic_interpolation(self):
+        parser = configparser.ConfigParser()
+        parser.read_string("""
+        [Paths]
+        home_dir: /Users
+        my_dir: %(home_dir1)s/lumberjack
+        my_pictures: %(my_dir)s/Pictures
+        """)
+        cm = self.assertRaises(configparser.InterpolationMissingOptionError)
+        with cm:
+            parser.get('Paths', 'my_dir')
+        self.assertIs(cm.exception.__suppress_context__, True)
+
+    def test_get_extended_interpolation(self):
+        parser = configparser.ConfigParser(
+          interpolation=configparser.ExtendedInterpolation())
+        parser.read_string("""
+        [Paths]
+        home_dir: /Users
+        my_dir: ${home_dir1}/lumberjack
+        my_pictures: ${my_dir}/Pictures
+        """)
+        cm = self.assertRaises(configparser.InterpolationMissingOptionError)
+        with cm:
+            parser.get('Paths', 'my_dir')
+        self.assertIs(cm.exception.__suppress_context__, True)
+
+    def test_missing_options(self):
+        parser = configparser.ConfigParser()
+        parser.read_string("""
+        [Paths]
+        home_dir: /Users
+        """)
+        with self.assertRaises(configparser.NoSectionError) as cm:
+            parser.options('test')
+        self.assertIs(cm.exception.__suppress_context__, True)
+
+    def test_missing_section(self):
+        config = configparser.ConfigParser()
+        with self.assertRaises(configparser.NoSectionError) as cm:
+            config.set('Section1', 'an_int', '15')
+        self.assertIs(cm.exception.__suppress_context__, True)
+
+    def test_remove_option(self):
+        config = configparser.ConfigParser()
+        with self.assertRaises(configparser.NoSectionError) as cm:
+            config.remove_option('Section1', 'an_int')
+        self.assertIs(cm.exception.__suppress_context__, True)
+
+
+class ConvertersTestCase(BasicTestCase, unittest.TestCase):
+    """Introduced in 3.5, issue #18159."""
+
+    config_class = configparser.ConfigParser
+
+    def newconfig(self, defaults=None):
+        instance = super().newconfig(defaults=defaults)
+        instance.converters['list'] = lambda v: [e.strip() for e in v.split()
+                                                 if e.strip()]
+        return instance
+
+    def test_converters(self):
+        cfg = self.newconfig()
+        self.assertIn('boolean', cfg.converters)
+        self.assertIn('list', cfg.converters)
+        self.assertIsNone(cfg.converters['int'])
+        self.assertIsNone(cfg.converters['float'])
+        self.assertIsNone(cfg.converters['boolean'])
+        self.assertIsNotNone(cfg.converters['list'])
+        self.assertEqual(len(cfg.converters), 4)
+        with self.assertRaises(ValueError):
+            cfg.converters[''] = lambda v: v
+        with self.assertRaises(ValueError):
+            cfg.converters[None] = lambda v: v
+        cfg.read_string("""
+        [s]
+        str = string
+        int = 1
+        float = 0.5
+        list = a b c d e f g
+        bool = yes
+        """)
+        s = cfg['s']
+        self.assertEqual(s['str'], 'string')
+        self.assertEqual(s['int'], '1')
+        self.assertEqual(s['float'], '0.5')
+        self.assertEqual(s['list'], 'a b c d e f g')
+        self.assertEqual(s['bool'], 'yes')
+        self.assertEqual(cfg.get('s', 'str'), 'string')
+        self.assertEqual(cfg.get('s', 'int'), '1')
+        self.assertEqual(cfg.get('s', 'float'), '0.5')
+        self.assertEqual(cfg.get('s', 'list'), 'a b c d e f g')
+        self.assertEqual(cfg.get('s', 'bool'), 'yes')
+        self.assertEqual(cfg.get('s', 'str'), 'string')
+        self.assertEqual(cfg.getint('s', 'int'), 1)
+        self.assertEqual(cfg.getfloat('s', 'float'), 0.5)
+        self.assertEqual(cfg.getlist('s', 'list'), ['a', 'b', 'c', 'd',
+                                                    'e', 'f', 'g'])
+        self.assertEqual(cfg.getboolean('s', 'bool'), True)
+        self.assertEqual(s.get('str'), 'string')
+        self.assertEqual(s.getint('int'), 1)
+        self.assertEqual(s.getfloat('float'), 0.5)
+        self.assertEqual(s.getlist('list'), ['a', 'b', 'c', 'd',
+                                             'e', 'f', 'g'])
+        self.assertEqual(s.getboolean('bool'), True)
+        with self.assertRaises(AttributeError):
+            cfg.getdecimal('s', 'float')
+        with self.assertRaises(AttributeError):
+            s.getdecimal('float')
+        import decimal
+        cfg.converters['decimal'] = decimal.Decimal
+        self.assertIn('decimal', cfg.converters)
+        self.assertIsNotNone(cfg.converters['decimal'])
+        self.assertEqual(len(cfg.converters), 5)
+        dec0_5 = decimal.Decimal('0.5')
+        self.assertEqual(cfg.getdecimal('s', 'float'), dec0_5)
+        self.assertEqual(s.getdecimal('float'), dec0_5)
+        del cfg.converters['decimal']
+        self.assertNotIn('decimal', cfg.converters)
+        self.assertEqual(len(cfg.converters), 4)
+        with self.assertRaises(AttributeError):
+            cfg.getdecimal('s', 'float')
+        with self.assertRaises(AttributeError):
+            s.getdecimal('float')
+        with self.assertRaises(KeyError):
+            del cfg.converters['decimal']
+        with self.assertRaises(KeyError):
+            del cfg.converters['']
+        with self.assertRaises(KeyError):
+            del cfg.converters[None]
+
+
+class BlatantOverrideConvertersTestCase(unittest.TestCase):
+    """What if somebody overrode a getboolean()? We want to make sure that in
+    this case the automatic converters do not kick in."""
+
+    config = """
+        [one]
+        one = false
+        two = false
+        three = long story short
+
+        [two]
+        one = false
+        two = false
+        three = four
+    """
+
+    def test_converters_at_init(self):
+        cfg = configparser.ConfigParser(converters={'len': len})
+        cfg.read_string(self.config)
+        self._test_len(cfg)
+        self.assertIsNotNone(cfg.converters['len'])
+
+    def test_inheritance(self):
+        class StrangeConfigParser(configparser.ConfigParser):
+            gettysburg = 'a historic borough in south central Pennsylvania'
+
+            def getboolean(self, section, option, *, raw=False, vars=None,
+                        fallback=configparser._UNSET):
+                if section == option:
+                    return True
+                return super().getboolean(section, option, raw=raw, vars=vars,
+                                          fallback=fallback)
+            def getlen(self, section, option, *, raw=False, vars=None,
+                       fallback=configparser._UNSET):
+                return self._get_conv(section, option, len, raw=raw, vars=vars,
+                                      fallback=fallback)
+
+        cfg = StrangeConfigParser()
+        cfg.read_string(self.config)
+        self._test_len(cfg)
+        self.assertIsNone(cfg.converters['len'])
+        self.assertTrue(cfg.getboolean('one', 'one'))
+        self.assertTrue(cfg.getboolean('two', 'two'))
+        self.assertFalse(cfg.getboolean('one', 'two'))
+        self.assertFalse(cfg.getboolean('two', 'one'))
+        cfg.converters['boolean'] = cfg._convert_to_boolean
+        self.assertFalse(cfg.getboolean('one', 'one'))
+        self.assertFalse(cfg.getboolean('two', 'two'))
+        self.assertFalse(cfg.getboolean('one', 'two'))
+        self.assertFalse(cfg.getboolean('two', 'one'))
+
+    def _test_len(self, cfg):
+        self.assertEqual(len(cfg.converters), 4)
+        self.assertIn('boolean', cfg.converters)
+        self.assertIn('len', cfg.converters)
+        self.assertNotIn('tysburg', cfg.converters)
+        self.assertIsNone(cfg.converters['int'])
+        self.assertIsNone(cfg.converters['float'])
+        self.assertIsNone(cfg.converters['boolean'])
+        self.assertEqual(cfg.getlen('one', 'one'), 5)
+        self.assertEqual(cfg.getlen('one', 'two'), 5)
+        self.assertEqual(cfg.getlen('one', 'three'), 16)
+        self.assertEqual(cfg.getlen('two', 'one'), 5)
+        self.assertEqual(cfg.getlen('two', 'two'), 5)
+        self.assertEqual(cfg.getlen('two', 'three'), 4)
+        self.assertEqual(cfg.getlen('two', 'four', fallback=0), 0)
+        with self.assertRaises(configparser.NoOptionError):
+            cfg.getlen('two', 'four')
+        self.assertEqual(cfg['one'].getlen('one'), 5)
+        self.assertEqual(cfg['one'].getlen('two'), 5)
+        self.assertEqual(cfg['one'].getlen('three'), 16)
+        self.assertEqual(cfg['two'].getlen('one'), 5)
+        self.assertEqual(cfg['two'].getlen('two'), 5)
+        self.assertEqual(cfg['two'].getlen('three'), 4)
+        self.assertEqual(cfg['two'].getlen('four', 0), 0)
+        self.assertEqual(cfg['two'].getlen('four'), None)
+
+    def test_instance_assignment(self):
+        cfg = configparser.ConfigParser()
+        cfg.getboolean = lambda section, option: True
+        cfg.getlen = lambda section, option: len(cfg[section][option])
+        cfg.read_string(self.config)
+        self.assertEqual(len(cfg.converters), 3)
+        self.assertIn('boolean', cfg.converters)
+        self.assertNotIn('len', cfg.converters)
+        self.assertIsNone(cfg.converters['int'])
+        self.assertIsNone(cfg.converters['float'])
+        self.assertIsNone(cfg.converters['boolean'])
+        self.assertTrue(cfg.getboolean('one', 'one'))
+        self.assertTrue(cfg.getboolean('two', 'two'))
+        self.assertTrue(cfg.getboolean('one', 'two'))
+        self.assertTrue(cfg.getboolean('two', 'one'))
+        cfg.converters['boolean'] = cfg._convert_to_boolean
+        self.assertFalse(cfg.getboolean('one', 'one'))
+        self.assertFalse(cfg.getboolean('two', 'two'))
+        self.assertFalse(cfg.getboolean('one', 'two'))
+        self.assertFalse(cfg.getboolean('two', 'one'))
+        self.assertEqual(cfg.getlen('one', 'one'), 5)
+        self.assertEqual(cfg.getlen('one', 'two'), 5)
+        self.assertEqual(cfg.getlen('one', 'three'), 16)
+        self.assertEqual(cfg.getlen('two', 'one'), 5)
+        self.assertEqual(cfg.getlen('two', 'two'), 5)
+        self.assertEqual(cfg.getlen('two', 'three'), 4)
+        # If a getter impl is assigned straight to the instance, it won't
+        # be available on the section proxies.
+        with self.assertRaises(AttributeError):
+            self.assertEqual(cfg['one'].getlen('one'), 5)
+        with self.assertRaises(AttributeError):
+            self.assertEqual(cfg['two'].getlen('one'), 5)
+
+
 if __name__ == '__main__':
     unittest.main()
diff --git a/Lib/test/test_contextlib.py b/Lib/test/test_contextlib.py
index 39cc776dbc..c52066be3c 100644
--- a/Lib/test/test_contextlib.py
+++ b/Lib/test/test_contextlib.py
@@ -718,60 +718,76 @@ class TestExitStack(unittest.TestCase):
         stack.push(cm)
         self.assertIs(stack._exit_callbacks[-1], cm)
 
-class TestRedirectStdout(unittest.TestCase):
+
+class TestRedirectStream:
+
+    redirect_stream = None
+    orig_stream = None
 
     @support.requires_docstrings
     def test_instance_docs(self):
         # Issue 19330: ensure context manager instances have good docstrings
-        cm_docstring = redirect_stdout.__doc__
-        obj = redirect_stdout(None)
+        cm_docstring = self.redirect_stream.__doc__
+        obj = self.redirect_stream(None)
         self.assertEqual(obj.__doc__, cm_docstring)
 
     def test_no_redirect_in_init(self):
-        orig_stdout = sys.stdout
-        redirect_stdout(None)
-        self.assertIs(sys.stdout, orig_stdout)
+        orig_stdout = getattr(sys, self.orig_stream)
+        self.redirect_stream(None)
+        self.assertIs(getattr(sys, self.orig_stream), orig_stdout)
 
     def test_redirect_to_string_io(self):
         f = io.StringIO()
         msg = "Consider an API like help(), which prints directly to stdout"
-        orig_stdout = sys.stdout
-        with redirect_stdout(f):
-            print(msg)
-        self.assertIs(sys.stdout, orig_stdout)
+        orig_stdout = getattr(sys, self.orig_stream)
+        with self.redirect_stream(f):
+            print(msg, file=getattr(sys, self.orig_stream))
+        self.assertIs(getattr(sys, self.orig_stream), orig_stdout)
         s = f.getvalue().strip()
         self.assertEqual(s, msg)
 
     def test_enter_result_is_target(self):
         f = io.StringIO()
-        with redirect_stdout(f) as enter_result:
+        with self.redirect_stream(f) as enter_result:
             self.assertIs(enter_result, f)
 
     def test_cm_is_reusable(self):
         f = io.StringIO()
-        write_to_f = redirect_stdout(f)
-        orig_stdout = sys.stdout
+        write_to_f = self.redirect_stream(f)
+        orig_stdout = getattr(sys, self.orig_stream)
         with write_to_f:
-            print("Hello", end=" ")
+            print("Hello", end=" ", file=getattr(sys, self.orig_stream))
         with write_to_f:
-            print("World!")
-        self.assertIs(sys.stdout, orig_stdout)
+            print("World!", file=getattr(sys, self.orig_stream))
+        self.assertIs(getattr(sys, self.orig_stream), orig_stdout)
         s = f.getvalue()
         self.assertEqual(s, "Hello World!\n")
 
     def test_cm_is_reentrant(self):
         f = io.StringIO()
-        write_to_f = redirect_stdout(f)
-        orig_stdout = sys.stdout
+        write_to_f = self.redirect_stream(f)
+        orig_stdout = getattr(sys, self.orig_stream)
         with write_to_f:
-            print("Hello", end=" ")
+            print("Hello", end=" ", file=getattr(sys, self.orig_stream))
             with write_to_f:
-                print("World!")
-        self.assertIs(sys.stdout, orig_stdout)
+                print("World!", file=getattr(sys, self.orig_stream))
+        self.assertIs(getattr(sys, self.orig_stream), orig_stdout)
         s = f.getvalue()
         self.assertEqual(s, "Hello World!\n")
 
 
+class TestRedirectStdout(TestRedirectStream, unittest.TestCase):
+
+    redirect_stream = redirect_stdout
+    orig_stream = "stdout"
+
+
+class TestRedirectStderr(TestRedirectStream, unittest.TestCase):
+
+    redirect_stream = redirect_stderr
+    orig_stream = "stderr"
+
+
 class TestSuppress(unittest.TestCase):
 
     @support.requires_docstrings
diff --git a/Lib/test/test_cprofile.py b/Lib/test/test_cprofile.py
index ce5d27edd6..f18983fbb2 100644
--- a/Lib/test/test_cprofile.py
+++ b/Lib/test/test_cprofile.py
@@ -11,7 +11,7 @@ from test.profilee import testfunc
 class CProfileTest(ProfileTest):
     profilerclass = cProfile.Profile
     profilermodule = cProfile
-    expected_max_output = "{built-in method max}"
+    expected_max_output = "{built-in method builtins.max}"
 
     def get_expected_output(self):
         return _ProfileOutput
@@ -72,9 +72,9 @@ profilee.py:84(helper2_indirect)                  <-       2    0.000    0.140
 profilee.py:88(helper2)                           <-       6    0.234    0.300  profilee.py:55(helper)
                                                            2    0.078    0.100  profilee.py:84(helper2_indirect)
 profilee.py:98(subhelper)                         <-       8    0.064    0.080  profilee.py:88(helper2)
-{built-in method exc_info}                        <-       4    0.000    0.000  profilee.py:73(helper1)
-{built-in method hasattr}                         <-       4    0.000    0.004  profilee.py:73(helper1)
+{built-in method builtins.hasattr}                <-       4    0.000    0.004  profilee.py:73(helper1)
                                                            8    0.000    0.008  profilee.py:88(helper2)
+{built-in method sys.exc_info}                    <-       4    0.000    0.000  profilee.py:73(helper1)
 {method 'append' of 'list' objects}               <-       4    0.000    0.000  profilee.py:73(helper1)"""
 _ProfileOutput['print_callees'] = """\
 <string>:1(<module>)                              ->       1    0.270    1.000  profilee.py:25(testfunc)
@@ -87,12 +87,12 @@ profilee.py:48(mul)                               ->
 profilee.py:55(helper)                            ->       4    0.116    0.120  profilee.py:73(helper1)
                                                            2    0.000    0.140  profilee.py:84(helper2_indirect)
                                                            6    0.234    0.300  profilee.py:88(helper2)
-profilee.py:73(helper1)                           ->       4    0.000    0.000  {built-in method exc_info}
+profilee.py:73(helper1)                           ->       4    0.000    0.004  {built-in method builtins.hasattr}
 profilee.py:84(helper2_indirect)                  ->       2    0.006    0.040  profilee.py:35(factorial)
                                                            2    0.078    0.100  profilee.py:88(helper2)
 profilee.py:88(helper2)                           ->       8    0.064    0.080  profilee.py:98(subhelper)
 profilee.py:98(subhelper)                         ->      16    0.016    0.016  profilee.py:110(__getattr__)
-{built-in method hasattr}                         ->      12    0.012    0.012  profilee.py:110(__getattr__)"""
+{built-in method builtins.hasattr}                ->      12    0.012    0.012  profilee.py:110(__getattr__)"""
 
 if __name__ == "__main__":
     main()
diff --git a/Lib/test/test_csv.py b/Lib/test/test_csv.py
index 7e2485f954..3f3f328849 100644
--- a/Lib/test/test_csv.py
+++ b/Lib/test/test_csv.py
@@ -575,6 +575,16 @@ class TestDictFields(unittest.TestCase):
             fileobj.readline() # header
             self.assertEqual(fileobj.read(), "10,,abc\r\n")
 
+    def test_write_multiple_dict_rows(self):
+        fileobj = StringIO()
+        writer = csv.DictWriter(fileobj, fieldnames=["f1", "f2", "f3"])
+        writer.writeheader()
+        self.assertEqual(fileobj.getvalue(), "f1,f2,f3\r\n")
+        writer.writerows([{"f1": 1, "f2": "abc", "f3": "f"},
+                          {"f1": 2, "f2": 5, "f3": "xyz"}])
+        self.assertEqual(fileobj.getvalue(),
+                         "f1,f2,f3\r\n1,abc,f\r\n2,5,xyz\r\n")
+
     def test_write_no_fields(self):
         fileobj = StringIO()
         self.assertRaises(TypeError, csv.DictWriter, fileobj)
@@ -773,7 +783,7 @@ class TestDialectValidity(unittest.TestCase):
         with self.assertRaises(csv.Error) as cm:
             mydialect()
         self.assertEqual(str(cm.exception),
-                         '"quotechar" must be an 1-character string')
+                         '"quotechar" must be a 1-character string')
 
         mydialect.quotechar = 4
         with self.assertRaises(csv.Error) as cm:
@@ -796,13 +806,13 @@ class TestDialectValidity(unittest.TestCase):
         with self.assertRaises(csv.Error) as cm:
             mydialect()
         self.assertEqual(str(cm.exception),
-                         '"delimiter" must be an 1-character string')
+                         '"delimiter" must be a 1-character string')
 
         mydialect.delimiter = ""
         with self.assertRaises(csv.Error) as cm:
             mydialect()
         self.assertEqual(str(cm.exception),
-                         '"delimiter" must be an 1-character string')
+                         '"delimiter" must be a 1-character string')
 
         mydialect.delimiter = b","
         with self.assertRaises(csv.Error) as cm:
diff --git a/Lib/test/test_datetime.py b/Lib/test/test_datetime.py
index d9ddb32363..2d4eb52c62 100644
--- a/Lib/test/test_datetime.py
+++ b/Lib/test/test_datetime.py
@@ -1,20 +1,20 @@
 import unittest
 import sys
+
 from test.support import import_fresh_module, run_unittest
 
 TESTS = 'test.datetimetester'
 
-# XXX: import_fresh_module() is supposed to leave sys.module cache untouched,
-# XXX: but it does not, so we have to save and restore it ourselves.
-save_sys_modules = sys.modules.copy()
 try:
     pure_tests = import_fresh_module(TESTS, fresh=['datetime', '_strptime'],
                                      blocked=['_datetime'])
     fast_tests = import_fresh_module(TESTS, fresh=['datetime',
                                                    '_datetime', '_strptime'])
 finally:
-    sys.modules.clear()
-    sys.modules.update(save_sys_modules)
+    # XXX: import_fresh_module() is supposed to leave sys.module cache untouched,
+    # XXX: but it does not, so we have to cleanup ourselves.
+    for modname in ['datetime', '_datetime', '_strptime']:
+        sys.modules.pop(modname, None)
 test_modules = [pure_tests, fast_tests]
 test_suffixes = ["_Pure", "_Fast"]
 # XXX(gb) First run all the _Pure tests, then all the _Fast tests.  You might
diff --git a/Lib/test/test_dbm_dumb.py b/Lib/test/test_dbm_dumb.py
index dc88ca64dc..ff63c88c0b 100644
--- a/Lib/test/test_dbm_dumb.py
+++ b/Lib/test/test_dbm_dumb.py
@@ -217,6 +217,14 @@ class DumbDBMTestCase(unittest.TestCase):
             self.assertEqual(str(cm.exception),
                              "DBM object has already been closed")
 
+    def test_create_new(self):
+        with dumbdbm.open(_fname, 'n') as f:
+            for k in self._dict:
+                f[k] = self._dict[k]
+
+        with dumbdbm.open(_fname, 'n') as f:
+            self.assertEqual(f.keys(), [])
+
     def test_eval(self):
         with open(_fname + '.dir', 'w') as stream:
             stream.write("str(print('Hacked!')), 0\n")
diff --git a/Lib/test/test_decimal.py b/Lib/test/test_decimal.py
index a178f6f3cc..137aaa537e 100644
--- a/Lib/test/test_decimal.py
+++ b/Lib/test/test_decimal.py
@@ -33,12 +33,13 @@ import unittest
 import numbers
 import locale
 from test.support import (run_unittest, run_doctest, is_resource_enabled,
-                          requires_IEEE_754)
+                          requires_IEEE_754, requires_docstrings)
 from test.support import (check_warnings, import_fresh_module, TestFailed,
                           run_with_locale, cpython_only)
 import random
 import time
 import warnings
+import inspect
 try:
     import threading
 except ImportError:
@@ -4174,9 +4175,7 @@ class CheckAttributes(unittest.TestCase):
         self.assertEqual(C.__version__, P.__version__)
         self.assertEqual(C.__libmpdec_version__, P.__libmpdec_version__)
 
-        x = dir(C)
-        y = [s for s in dir(P) if '__' in s or not s.startswith('_')]
-        self.assertEqual(set(x) - set(y), set())
+        self.assertEqual(dir(C), dir(P))
 
     def test_context_attributes(self):
 
@@ -4455,18 +4454,6 @@ class PyCoverage(Coverage):
 class PyFunctionality(unittest.TestCase):
     """Extra functionality in decimal.py"""
 
-    def test_py_quantize_watchexp(self):
-        # watchexp functionality
-        Decimal = P.Decimal
-        localcontext = P.localcontext
-
-        with localcontext() as c:
-            c.prec = 1
-            c.Emax = 1
-            c.Emin = -1
-            x = Decimal(99999).quantize(Decimal("1e3"), watchexp=False)
-            self.assertEqual(x, Decimal('1.00E+5'))
-
     def test_py_alternate_formatting(self):
         # triples giving a format, a Decimal, and the expected result
         Decimal = P.Decimal
@@ -5409,6 +5396,143 @@ class CWhitebox(unittest.TestCase):
             y = Decimal(10**(9*25)).__sizeof__()
             self.assertEqual(y, x+4)
 
+@requires_docstrings
+@unittest.skipUnless(C, "test requires C version")
+class SignatureTest(unittest.TestCase):
+    """Function signatures"""
+
+    def test_inspect_module(self):
+        for attr in dir(P):
+            if attr.startswith('_'):
+                continue
+            p_func = getattr(P, attr)
+            c_func = getattr(C, attr)
+            if (attr == 'Decimal' or attr == 'Context' or
+                inspect.isfunction(p_func)):
+                p_sig = inspect.signature(p_func)
+                c_sig = inspect.signature(c_func)
+
+                # parameter names:
+                c_names = list(c_sig.parameters.keys())
+                p_names = [x for x in p_sig.parameters.keys() if not
+                           x.startswith('_')]
+
+                self.assertEqual(c_names, p_names,
+                                 msg="parameter name mismatch in %s" % p_func)
+
+                c_kind = [x.kind for x in c_sig.parameters.values()]
+                p_kind = [x[1].kind for x in p_sig.parameters.items() if not
+                          x[0].startswith('_')]
+
+                # parameters:
+                if attr != 'setcontext':
+                    self.assertEqual(c_kind, p_kind,
+                                     msg="parameter kind mismatch in %s" % p_func)
+
+    def test_inspect_types(self):
+
+        POS = inspect._ParameterKind.POSITIONAL_ONLY
+        POS_KWD = inspect._ParameterKind.POSITIONAL_OR_KEYWORD
+
+        # Type heuristic (type annotations would help!):
+        pdict = {C: {'other': C.Decimal(1),
+                     'third': C.Decimal(1),
+                     'x': C.Decimal(1),
+                     'y': C.Decimal(1),
+                     'z': C.Decimal(1),
+                     'a': C.Decimal(1),
+                     'b': C.Decimal(1),
+                     'c': C.Decimal(1),
+                     'exp': C.Decimal(1),
+                     'modulo': C.Decimal(1),
+                     'num': "1",
+                     'f': 1.0,
+                     'rounding': C.ROUND_HALF_UP,
+                     'context': C.getcontext()},
+                 P: {'other': P.Decimal(1),
+                     'third': P.Decimal(1),
+                     'a': P.Decimal(1),
+                     'b': P.Decimal(1),
+                     'c': P.Decimal(1),
+                     'exp': P.Decimal(1),
+                     'modulo': P.Decimal(1),
+                     'num': "1",
+                     'f': 1.0,
+                     'rounding': P.ROUND_HALF_UP,
+                     'context': P.getcontext()}}
+
+        def mkargs(module, sig):
+            args = []
+            kwargs = {}
+            for name, param in sig.parameters.items():
+                if name == 'self': continue
+                if param.kind == POS:
+                    args.append(pdict[module][name])
+                elif param.kind == POS_KWD:
+                    kwargs[name] = pdict[module][name]
+                else:
+                    raise TestFailed("unexpected parameter kind")
+            return args, kwargs
+
+        def tr(s):
+            """The C Context docstrings use 'x' in order to prevent confusion
+               with the article 'a' in the descriptions."""
+            if s == 'x': return 'a'
+            if s == 'y': return 'b'
+            if s == 'z': return 'c'
+            return s
+
+        def doit(ty):
+            p_type = getattr(P, ty)
+            c_type = getattr(C, ty)
+            for attr in dir(p_type):
+                if attr.startswith('_'):
+                    continue
+                p_func = getattr(p_type, attr)
+                c_func = getattr(c_type, attr)
+                if inspect.isfunction(p_func):
+                    p_sig = inspect.signature(p_func)
+                    c_sig = inspect.signature(c_func)
+
+                    # parameter names:
+                    p_names = list(p_sig.parameters.keys())
+                    c_names = [tr(x) for x in c_sig.parameters.keys()]
+
+                    self.assertEqual(c_names, p_names,
+                                     msg="parameter name mismatch in %s" % p_func)
+
+                    p_kind = [x.kind for x in p_sig.parameters.values()]
+                    c_kind = [x.kind for x in c_sig.parameters.values()]
+
+                    # 'self' parameter:
+                    self.assertIs(p_kind[0], POS_KWD)
+                    self.assertIs(c_kind[0], POS)
+
+                    # remaining parameters:
+                    if ty == 'Decimal':
+                        self.assertEqual(c_kind[1:], p_kind[1:],
+                                         msg="parameter kind mismatch in %s" % p_func)
+                    else: # Context methods are positional only in the C version.
+                        self.assertEqual(len(c_kind), len(p_kind),
+                                         msg="parameter kind mismatch in %s" % p_func)
+
+                    # Run the function:
+                    args, kwds = mkargs(C, c_sig)
+                    try:
+                        getattr(c_type(9), attr)(*args, **kwds)
+                    except Exception as err:
+                        raise TestFailed("invalid signature for %s: %s %s" % (c_func, args, kwds))
+
+                    args, kwds = mkargs(P, p_sig)
+                    try:
+                        getattr(p_type(9), attr)(*args, **kwds)
+                    except Exception as err:
+                        raise TestFailed("invalid signature for %s: %s %s" % (p_func, args, kwds))
+
+        doit('Decimal')
+        doit('Context')
+
+
 all_tests = [
   CExplicitConstructionTest, PyExplicitConstructionTest,
   CImplicitConstructionTest, PyImplicitConstructionTest,
@@ -5434,6 +5558,7 @@ if not C:
     all_tests = all_tests[1::2]
 else:
     all_tests.insert(0, CheckAttributes)
+    all_tests.insert(1, SignatureTest)
 
 
 def test_main(arith=None, verbose=None, todo_tests=None, debug=None):
diff --git a/Lib/test/test_defaultdict.py b/Lib/test/test_defaultdict.py
index 532d535981..48d1cb537b 100644
--- a/Lib/test/test_defaultdict.py
+++ b/Lib/test/test_defaultdict.py
@@ -157,8 +157,9 @@ class TestDefaultDict(unittest.TestCase):
             def _factory(self):
                 return []
         d = sub()
-        self.assertTrue(repr(d).startswith(
-            "defaultdict(<bound method sub._factory of defaultdict(..."))
+        self.assertRegex(repr(d),
+            r"defaultdict\(<bound method .*sub\._factory "
+            r"of defaultdict\(\.\.\., \{\}\)>, \{\}\)")
 
         # NOTE: printing a subclass of a builtin type does not call its
         # tp_print slot. So this part is essentially the same test as above.
diff --git a/Lib/test/test_deque.py b/Lib/test/test_deque.py
index 5ecbc73c99..e336e5a384 100644
--- a/Lib/test/test_deque.py
+++ b/Lib/test/test_deque.py
@@ -508,6 +508,11 @@ class TestBasic(unittest.TestCase):
         for s in ('abcd', range(2000)):
             self.assertEqual(list(reversed(deque(s))), list(reversed(s)))
 
+    def test_reversed_new(self):
+        klass = type(reversed(deque()))
+        for s in ('abcd', range(2000)):
+            self.assertEqual(list(klass(deque(s))), list(reversed(s)))
+
     def test_gc_doesnt_blowup(self):
         import gc
         # This used to assert-fail in deque_traverse() under a debug
diff --git a/Lib/test/test_descr.py b/Lib/test/test_descr.py
index 1de2a992e6..8d6205afbf 100644
--- a/Lib/test/test_descr.py
+++ b/Lib/test/test_descr.py
@@ -1026,6 +1026,22 @@ order (MRO) for bases """
         self.assertEqual(x.foo, 1)
         self.assertEqual(x.__dict__, {'foo': 1})
 
+    def test_object_class_assignment_between_heaptypes_and_nonheaptypes(self):
+        class SubType(types.ModuleType):
+            a = 1
+
+        m = types.ModuleType("m")
+        self.assertTrue(m.__class__ is types.ModuleType)
+        self.assertFalse(hasattr(m, "a"))
+
+        m.__class__ = SubType
+        self.assertTrue(m.__class__ is SubType)
+        self.assertTrue(hasattr(m, "a"))
+
+        m.__class__ = types.ModuleType
+        self.assertTrue(m.__class__ is types.ModuleType)
+        self.assertFalse(hasattr(m, "a"))
+
     def test_slots(self):
         # Testing __slots__...
         class C0(object):
@@ -4160,6 +4176,7 @@ order (MRO) for bases """
                 ('__add__',      'x + y',                   'x += y'),
                 ('__sub__',      'x - y',                   'x -= y'),
                 ('__mul__',      'x * y',                   'x *= y'),
+                ('__matmul__',   'x @ y',                   'x @= y'),
                 ('__truediv__',  'operator.truediv(x, y)',  None),
                 ('__floordiv__', 'operator.floordiv(x, y)', None),
                 ('__div__',      'x / y',                   'x /= y'),
@@ -4422,6 +4439,61 @@ order (MRO) for bases """
         self.assertIn("__dict__", Base.__dict__)
         self.assertNotIn("__dict__", Sub.__dict__)
 
+    def test_bound_method_repr(self):
+        class Foo:
+            def method(self):
+                pass
+        self.assertRegex(repr(Foo().method),
+            r"<bound method .*Foo\.method of <.*Foo object at .*>>")
+
+
+        class Base:
+            def method(self):
+                pass
+        class Derived1(Base):
+            pass
+        class Derived2(Base):
+            def method(self):
+                pass
+        base = Base()
+        derived1 = Derived1()
+        derived2 = Derived2()
+        super_d2 = super(Derived2, derived2)
+        self.assertRegex(repr(base.method),
+            r"<bound method .*Base\.method of <.*Base object at .*>>")
+        self.assertRegex(repr(derived1.method),
+            r"<bound method .*Base\.method of <.*Derived1 object at .*>>")
+        self.assertRegex(repr(derived2.method),
+            r"<bound method .*Derived2\.method of <.*Derived2 object at .*>>")
+        self.assertRegex(repr(super_d2.method),
+            r"<bound method .*Base\.method of <.*Derived2 object at .*>>")
+
+        class Foo:
+            @classmethod
+            def method(cls):
+                pass
+        foo = Foo()
+        self.assertRegex(repr(foo.method), # access via instance
+            r"<bound method .*Foo\.method of <class '.*Foo'>>")
+        self.assertRegex(repr(Foo.method), # access via the class
+            r"<bound method .*Foo\.method of <class '.*Foo'>>")
+
+
+        class MyCallable:
+            def __call__(self, arg):
+                pass
+        func = MyCallable() # func has no __name__ or __qualname__ attributes
+        instance = object()
+        method = types.MethodType(func, instance)
+        self.assertRegex(repr(method),
+            r"<bound method \? of <object object at .*>>")
+        func.__name__ = "name"
+        self.assertRegex(repr(method),
+            r"<bound method name of <object object at .*>>")
+        func.__qualname__ = "qualname"
+        self.assertRegex(repr(method),
+            r"<bound method qualname of <object object at .*>>")
+
 
 class DictProxyTests(unittest.TestCase):
     def setUp(self):
@@ -4536,26 +4608,15 @@ class PicklingTests(unittest.TestCase):
 
     def _check_reduce(self, proto, obj, args=(), kwargs={}, state=None,
                       listitems=None, dictitems=None):
-        if proto >= 4:
+        if proto >= 2:
             reduce_value = obj.__reduce_ex__(proto)
-            self.assertEqual(reduce_value[:3],
-                             (copyreg.__newobj_ex__,
-                              (type(obj), args, kwargs),
-                              state))
-            if listitems is not None:
-                self.assertListEqual(list(reduce_value[3]), listitems)
+            if kwargs:
+                self.assertEqual(reduce_value[0], copyreg.__newobj_ex__)
+                self.assertEqual(reduce_value[1], (type(obj), args, kwargs))
             else:
-                self.assertIsNone(reduce_value[3])
-            if dictitems is not None:
-                self.assertDictEqual(dict(reduce_value[4]), dictitems)
-            else:
-                self.assertIsNone(reduce_value[4])
-        elif proto >= 2:
-            reduce_value = obj.__reduce_ex__(proto)
-            self.assertEqual(reduce_value[:3],
-                             (copyreg.__newobj__,
-                              (type(obj),) + args,
-                              state))
+                self.assertEqual(reduce_value[0], copyreg.__newobj__)
+                self.assertEqual(reduce_value[1], (type(obj),) + args)
+            self.assertEqual(reduce_value[2], state)
             if listitems is not None:
                 self.assertListEqual(list(reduce_value[3]), listitems)
             else:
diff --git a/Lib/test/test_dis.py b/Lib/test/test_dis.py
index b8daff725c..4f30183ac0 100644
--- a/Lib/test/test_dis.py
+++ b/Lib/test/test_dis.py
@@ -230,6 +230,9 @@ dis_traceback = """\
        TRACEBACK_CODE.co_firstlineno + 4,
        TRACEBACK_CODE.co_firstlineno + 5)
 
+def _g(x):
+    yield x
+
 class DisTests(unittest.TestCase):
 
     def get_disassembly(self, func, lasti=-1, wrapper=True):
@@ -315,6 +318,11 @@ class DisTests(unittest.TestCase):
         method_bytecode = _C(1).__init__.__code__.co_code
         self.do_disassembly_test(method_bytecode, dis_c_instance_method_bytes)
 
+    def test_disassemble_generator(self):
+        gen_func_disas = self.get_disassembly(_g)  # Disassemble generator function
+        gen_disas = self.get_disassembly(_g(1))  # Disassemble generator itself
+        self.assertEqual(gen_disas, gen_func_disas)
+
     def test_dis_none(self):
         try:
             del sys.last_traceback
@@ -561,10 +569,10 @@ expected_jumpy_line = 1
 #_instructions = dis.get_instructions(outer, first_line=expected_outer_line)
 #print('expected_opinfo_outer = [\n  ',
       #',\n  '.join(map(str, _instructions)), ',\n]', sep='')
-#_instructions = dis.get_instructions(outer(), first_line=expected_outer_line)
+#_instructions = dis.get_instructions(outer(), first_line=expected_f_line)
 #print('expected_opinfo_f = [\n  ',
       #',\n  '.join(map(str, _instructions)), ',\n]', sep='')
-#_instructions = dis.get_instructions(outer()(), first_line=expected_outer_line)
+#_instructions = dis.get_instructions(outer()(), first_line=expected_inner_line)
 #print('expected_opinfo_inner = [\n  ',
       #',\n  '.join(map(str, _instructions)), ',\n]', sep='')
 #_instructions = dis.get_instructions(jumpy, first_line=expected_jumpy_line)
@@ -635,12 +643,12 @@ expected_opinfo_inner = [
 ]
 
 expected_opinfo_jumpy = [
-  Instruction(opname='SETUP_LOOP', opcode=120, arg=74, argval=77, argrepr='to 77', offset=0, starts_line=3, is_jump_target=False),
+  Instruction(opname='SETUP_LOOP', opcode=120, arg=68, argval=71, argrepr='to 71', offset=0, starts_line=3, is_jump_target=False),
   Instruction(opname='LOAD_GLOBAL', opcode=116, arg=0, argval='range', argrepr='range', offset=3, starts_line=None, is_jump_target=False),
   Instruction(opname='LOAD_CONST', opcode=100, arg=1, argval=10, argrepr='10', offset=6, starts_line=None, is_jump_target=False),
   Instruction(opname='CALL_FUNCTION', opcode=131, arg=1, argval=1, argrepr='1 positional, 0 keyword pair', offset=9, starts_line=None, is_jump_target=False),
   Instruction(opname='GET_ITER', opcode=68, arg=None, argval=None, argrepr='', offset=12, starts_line=None, is_jump_target=False),
-  Instruction(opname='FOR_ITER', opcode=93, arg=50, argval=66, argrepr='to 66', offset=13, starts_line=None, is_jump_target=True),
+  Instruction(opname='FOR_ITER', opcode=93, arg=44, argval=60, argrepr='to 60', offset=13, starts_line=None, is_jump_target=True),
   Instruction(opname='STORE_FAST', opcode=125, arg=0, argval='i', argrepr='i', offset=16, starts_line=None, is_jump_target=False),
   Instruction(opname='LOAD_GLOBAL', opcode=116, arg=1, argval='print', argrepr='print', offset=19, starts_line=4, is_jump_target=False),
   Instruction(opname='LOAD_FAST', opcode=124, arg=0, argval='i', argrepr='i', offset=22, starts_line=None, is_jump_target=False),
@@ -649,92 +657,88 @@ expected_opinfo_jumpy = [
   Instruction(opname='LOAD_FAST', opcode=124, arg=0, argval='i', argrepr='i', offset=29, starts_line=5, is_jump_target=False),
   Instruction(opname='LOAD_CONST', opcode=100, arg=2, argval=4, argrepr='4', offset=32, starts_line=None, is_jump_target=False),
   Instruction(opname='COMPARE_OP', opcode=107, arg=0, argval='<', argrepr='<', offset=35, starts_line=None, is_jump_target=False),
-  Instruction(opname='POP_JUMP_IF_FALSE', opcode=114, arg=47, argval=47, argrepr='', offset=38, starts_line=None, is_jump_target=False),
+  Instruction(opname='POP_JUMP_IF_FALSE', opcode=114, arg=44, argval=44, argrepr='', offset=38, starts_line=None, is_jump_target=False),
   Instruction(opname='JUMP_ABSOLUTE', opcode=113, arg=13, argval=13, argrepr='', offset=41, starts_line=6, is_jump_target=False),
-  Instruction(opname='JUMP_FORWARD', opcode=110, arg=0, argval=47, argrepr='to 47', offset=44, starts_line=None, is_jump_target=False),
-  Instruction(opname='LOAD_FAST', opcode=124, arg=0, argval='i', argrepr='i', offset=47, starts_line=7, is_jump_target=True),
-  Instruction(opname='LOAD_CONST', opcode=100, arg=3, argval=6, argrepr='6', offset=50, starts_line=None, is_jump_target=False),
-  Instruction(opname='COMPARE_OP', opcode=107, arg=4, argval='>', argrepr='>', offset=53, starts_line=None, is_jump_target=False),
-  Instruction(opname='POP_JUMP_IF_FALSE', opcode=114, arg=13, argval=13, argrepr='', offset=56, starts_line=None, is_jump_target=False),
-  Instruction(opname='BREAK_LOOP', opcode=80, arg=None, argval=None, argrepr='', offset=59, starts_line=8, is_jump_target=False),
-  Instruction(opname='JUMP_ABSOLUTE', opcode=113, arg=13, argval=13, argrepr='', offset=60, starts_line=None, is_jump_target=False),
-  Instruction(opname='JUMP_ABSOLUTE', opcode=113, arg=13, argval=13, argrepr='', offset=63, starts_line=None, is_jump_target=False),
-  Instruction(opname='POP_BLOCK', opcode=87, arg=None, argval=None, argrepr='', offset=66, starts_line=None, is_jump_target=True),
-  Instruction(opname='LOAD_GLOBAL', opcode=116, arg=1, argval='print', argrepr='print', offset=67, starts_line=10, is_jump_target=False),
-  Instruction(opname='LOAD_CONST', opcode=100, arg=4, argval='I can haz else clause?', argrepr="'I can haz else clause?'", offset=70, starts_line=None, is_jump_target=False),
-  Instruction(opname='CALL_FUNCTION', opcode=131, arg=1, argval=1, argrepr='1 positional, 0 keyword pair', offset=73, starts_line=None, is_jump_target=False),
-  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=76, starts_line=None, is_jump_target=False),
-  Instruction(opname='SETUP_LOOP', opcode=120, arg=74, argval=154, argrepr='to 154', offset=77, starts_line=11, is_jump_target=True),
-  Instruction(opname='LOAD_FAST', opcode=124, arg=0, argval='i', argrepr='i', offset=80, starts_line=None, is_jump_target=True),
-  Instruction(opname='POP_JUMP_IF_FALSE', opcode=114, arg=143, argval=143, argrepr='', offset=83, starts_line=None, is_jump_target=False),
-  Instruction(opname='LOAD_GLOBAL', opcode=116, arg=1, argval='print', argrepr='print', offset=86, starts_line=12, is_jump_target=False),
-  Instruction(opname='LOAD_FAST', opcode=124, arg=0, argval='i', argrepr='i', offset=89, starts_line=None, is_jump_target=False),
-  Instruction(opname='CALL_FUNCTION', opcode=131, arg=1, argval=1, argrepr='1 positional, 0 keyword pair', offset=92, starts_line=None, is_jump_target=False),
-  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=95, starts_line=None, is_jump_target=False),
-  Instruction(opname='LOAD_FAST', opcode=124, arg=0, argval='i', argrepr='i', offset=96, starts_line=13, is_jump_target=False),
-  Instruction(opname='LOAD_CONST', opcode=100, arg=5, argval=1, argrepr='1', offset=99, starts_line=None, is_jump_target=False),
-  Instruction(opname='INPLACE_SUBTRACT', opcode=56, arg=None, argval=None, argrepr='', offset=102, starts_line=None, is_jump_target=False),
-  Instruction(opname='STORE_FAST', opcode=125, arg=0, argval='i', argrepr='i', offset=103, starts_line=None, is_jump_target=False),
-  Instruction(opname='LOAD_FAST', opcode=124, arg=0, argval='i', argrepr='i', offset=106, starts_line=14, is_jump_target=False),
-  Instruction(opname='LOAD_CONST', opcode=100, arg=3, argval=6, argrepr='6', offset=109, starts_line=None, is_jump_target=False),
-  Instruction(opname='COMPARE_OP', opcode=107, arg=4, argval='>', argrepr='>', offset=112, starts_line=None, is_jump_target=False),
-  Instruction(opname='POP_JUMP_IF_FALSE', opcode=114, arg=124, argval=124, argrepr='', offset=115, starts_line=None, is_jump_target=False),
-  Instruction(opname='JUMP_ABSOLUTE', opcode=113, arg=80, argval=80, argrepr='', offset=118, starts_line=15, is_jump_target=False),
-  Instruction(opname='JUMP_FORWARD', opcode=110, arg=0, argval=124, argrepr='to 124', offset=121, starts_line=None, is_jump_target=False),
-  Instruction(opname='LOAD_FAST', opcode=124, arg=0, argval='i', argrepr='i', offset=124, starts_line=16, is_jump_target=True),
-  Instruction(opname='LOAD_CONST', opcode=100, arg=2, argval=4, argrepr='4', offset=127, starts_line=None, is_jump_target=False),
-  Instruction(opname='COMPARE_OP', opcode=107, arg=0, argval='<', argrepr='<', offset=130, starts_line=None, is_jump_target=False),
-  Instruction(opname='POP_JUMP_IF_FALSE', opcode=114, arg=80, argval=80, argrepr='', offset=133, starts_line=None, is_jump_target=False),
-  Instruction(opname='BREAK_LOOP', opcode=80, arg=None, argval=None, argrepr='', offset=136, starts_line=17, is_jump_target=False),
-  Instruction(opname='JUMP_ABSOLUTE', opcode=113, arg=80, argval=80, argrepr='', offset=137, starts_line=None, is_jump_target=False),
-  Instruction(opname='JUMP_ABSOLUTE', opcode=113, arg=80, argval=80, argrepr='', offset=140, starts_line=None, is_jump_target=False),
-  Instruction(opname='POP_BLOCK', opcode=87, arg=None, argval=None, argrepr='', offset=143, starts_line=None, is_jump_target=True),
-  Instruction(opname='LOAD_GLOBAL', opcode=116, arg=1, argval='print', argrepr='print', offset=144, starts_line=19, is_jump_target=False),
-  Instruction(opname='LOAD_CONST', opcode=100, arg=6, argval='Who let lolcatz into this test suite?', argrepr="'Who let lolcatz into this test suite?'", offset=147, starts_line=None, is_jump_target=False),
-  Instruction(opname='CALL_FUNCTION', opcode=131, arg=1, argval=1, argrepr='1 positional, 0 keyword pair', offset=150, starts_line=None, is_jump_target=False),
-  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=153, starts_line=None, is_jump_target=False),
-  Instruction(opname='SETUP_FINALLY', opcode=122, arg=72, argval=229, argrepr='to 229', offset=154, starts_line=20, is_jump_target=True),
-  Instruction(opname='SETUP_EXCEPT', opcode=121, arg=12, argval=172, argrepr='to 172', offset=157, starts_line=None, is_jump_target=False),
-  Instruction(opname='LOAD_CONST', opcode=100, arg=5, argval=1, argrepr='1', offset=160, starts_line=21, is_jump_target=False),
-  Instruction(opname='LOAD_CONST', opcode=100, arg=7, argval=0, argrepr='0', offset=163, starts_line=None, is_jump_target=False),
-  Instruction(opname='BINARY_TRUE_DIVIDE', opcode=27, arg=None, argval=None, argrepr='', offset=166, starts_line=None, is_jump_target=False),
-  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=167, starts_line=None, is_jump_target=False),
-  Instruction(opname='POP_BLOCK', opcode=87, arg=None, argval=None, argrepr='', offset=168, starts_line=None, is_jump_target=False),
-  Instruction(opname='JUMP_FORWARD', opcode=110, arg=28, argval=200, argrepr='to 200', offset=169, starts_line=None, is_jump_target=False),
-  Instruction(opname='DUP_TOP', opcode=4, arg=None, argval=None, argrepr='', offset=172, starts_line=22, is_jump_target=True),
-  Instruction(opname='LOAD_GLOBAL', opcode=116, arg=2, argval='ZeroDivisionError', argrepr='ZeroDivisionError', offset=173, starts_line=None, is_jump_target=False),
-  Instruction(opname='COMPARE_OP', opcode=107, arg=10, argval='exception match', argrepr='exception match', offset=176, starts_line=None, is_jump_target=False),
-  Instruction(opname='POP_JUMP_IF_FALSE', opcode=114, arg=199, argval=199, argrepr='', offset=179, starts_line=None, is_jump_target=False),
+  Instruction(opname='LOAD_FAST', opcode=124, arg=0, argval='i', argrepr='i', offset=44, starts_line=7, is_jump_target=True),
+  Instruction(opname='LOAD_CONST', opcode=100, arg=3, argval=6, argrepr='6', offset=47, starts_line=None, is_jump_target=False),
+  Instruction(opname='COMPARE_OP', opcode=107, arg=4, argval='>', argrepr='>', offset=50, starts_line=None, is_jump_target=False),
+  Instruction(opname='POP_JUMP_IF_FALSE', opcode=114, arg=13, argval=13, argrepr='', offset=53, starts_line=None, is_jump_target=False),
+  Instruction(opname='BREAK_LOOP', opcode=80, arg=None, argval=None, argrepr='', offset=56, starts_line=8, is_jump_target=False),
+  Instruction(opname='JUMP_ABSOLUTE', opcode=113, arg=13, argval=13, argrepr='', offset=57, starts_line=None, is_jump_target=False),
+  Instruction(opname='POP_BLOCK', opcode=87, arg=None, argval=None, argrepr='', offset=60, starts_line=None, is_jump_target=True),
+  Instruction(opname='LOAD_GLOBAL', opcode=116, arg=1, argval='print', argrepr='print', offset=61, starts_line=10, is_jump_target=False),
+  Instruction(opname='LOAD_CONST', opcode=100, arg=4, argval='I can haz else clause?', argrepr="'I can haz else clause?'", offset=64, starts_line=None, is_jump_target=False),
+  Instruction(opname='CALL_FUNCTION', opcode=131, arg=1, argval=1, argrepr='1 positional, 0 keyword pair', offset=67, starts_line=None, is_jump_target=False),
+  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=70, starts_line=None, is_jump_target=False),
+  Instruction(opname='SETUP_LOOP', opcode=120, arg=68, argval=142, argrepr='to 142', offset=71, starts_line=11, is_jump_target=True),
+  Instruction(opname='LOAD_FAST', opcode=124, arg=0, argval='i', argrepr='i', offset=74, starts_line=None, is_jump_target=True),
+  Instruction(opname='POP_JUMP_IF_FALSE', opcode=114, arg=131, argval=131, argrepr='', offset=77, starts_line=None, is_jump_target=False),
+  Instruction(opname='LOAD_GLOBAL', opcode=116, arg=1, argval='print', argrepr='print', offset=80, starts_line=12, is_jump_target=False),
+  Instruction(opname='LOAD_FAST', opcode=124, arg=0, argval='i', argrepr='i', offset=83, starts_line=None, is_jump_target=False),
+  Instruction(opname='CALL_FUNCTION', opcode=131, arg=1, argval=1, argrepr='1 positional, 0 keyword pair', offset=86, starts_line=None, is_jump_target=False),
+  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=89, starts_line=None, is_jump_target=False),
+  Instruction(opname='LOAD_FAST', opcode=124, arg=0, argval='i', argrepr='i', offset=90, starts_line=13, is_jump_target=False),
+  Instruction(opname='LOAD_CONST', opcode=100, arg=5, argval=1, argrepr='1', offset=93, starts_line=None, is_jump_target=False),
+  Instruction(opname='INPLACE_SUBTRACT', opcode=56, arg=None, argval=None, argrepr='', offset=96, starts_line=None, is_jump_target=False),
+  Instruction(opname='STORE_FAST', opcode=125, arg=0, argval='i', argrepr='i', offset=97, starts_line=None, is_jump_target=False),
+  Instruction(opname='LOAD_FAST', opcode=124, arg=0, argval='i', argrepr='i', offset=100, starts_line=14, is_jump_target=False),
+  Instruction(opname='LOAD_CONST', opcode=100, arg=3, argval=6, argrepr='6', offset=103, starts_line=None, is_jump_target=False),
+  Instruction(opname='COMPARE_OP', opcode=107, arg=4, argval='>', argrepr='>', offset=106, starts_line=None, is_jump_target=False),
+  Instruction(opname='POP_JUMP_IF_FALSE', opcode=114, arg=115, argval=115, argrepr='', offset=109, starts_line=None, is_jump_target=False),
+  Instruction(opname='JUMP_ABSOLUTE', opcode=113, arg=74, argval=74, argrepr='', offset=112, starts_line=15, is_jump_target=False),
+  Instruction(opname='LOAD_FAST', opcode=124, arg=0, argval='i', argrepr='i', offset=115, starts_line=16, is_jump_target=True),
+  Instruction(opname='LOAD_CONST', opcode=100, arg=2, argval=4, argrepr='4', offset=118, starts_line=None, is_jump_target=False),
+  Instruction(opname='COMPARE_OP', opcode=107, arg=0, argval='<', argrepr='<', offset=121, starts_line=None, is_jump_target=False),
+  Instruction(opname='POP_JUMP_IF_FALSE', opcode=114, arg=74, argval=74, argrepr='', offset=124, starts_line=None, is_jump_target=False),
+  Instruction(opname='BREAK_LOOP', opcode=80, arg=None, argval=None, argrepr='', offset=127, starts_line=17, is_jump_target=False),
+  Instruction(opname='JUMP_ABSOLUTE', opcode=113, arg=74, argval=74, argrepr='', offset=128, starts_line=None, is_jump_target=False),
+  Instruction(opname='POP_BLOCK', opcode=87, arg=None, argval=None, argrepr='', offset=131, starts_line=None, is_jump_target=True),
+  Instruction(opname='LOAD_GLOBAL', opcode=116, arg=1, argval='print', argrepr='print', offset=132, starts_line=19, is_jump_target=False),
+  Instruction(opname='LOAD_CONST', opcode=100, arg=6, argval='Who let lolcatz into this test suite?', argrepr="'Who let lolcatz into this test suite?'", offset=135, starts_line=None, is_jump_target=False),
+  Instruction(opname='CALL_FUNCTION', opcode=131, arg=1, argval=1, argrepr='1 positional, 0 keyword pair', offset=138, starts_line=None, is_jump_target=False),
+  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=141, starts_line=None, is_jump_target=False),
+  Instruction(opname='SETUP_FINALLY', opcode=122, arg=72, argval=217, argrepr='to 217', offset=142, starts_line=20, is_jump_target=True),
+  Instruction(opname='SETUP_EXCEPT', opcode=121, arg=12, argval=160, argrepr='to 160', offset=145, starts_line=None, is_jump_target=False),
+  Instruction(opname='LOAD_CONST', opcode=100, arg=5, argval=1, argrepr='1', offset=148, starts_line=21, is_jump_target=False),
+  Instruction(opname='LOAD_CONST', opcode=100, arg=7, argval=0, argrepr='0', offset=151, starts_line=None, is_jump_target=False),
+  Instruction(opname='BINARY_TRUE_DIVIDE', opcode=27, arg=None, argval=None, argrepr='', offset=154, starts_line=None, is_jump_target=False),
+  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=155, starts_line=None, is_jump_target=False),
+  Instruction(opname='POP_BLOCK', opcode=87, arg=None, argval=None, argrepr='', offset=156, starts_line=None, is_jump_target=False),
+  Instruction(opname='JUMP_FORWARD', opcode=110, arg=28, argval=188, argrepr='to 188', offset=157, starts_line=None, is_jump_target=False),
+  Instruction(opname='DUP_TOP', opcode=4, arg=None, argval=None, argrepr='', offset=160, starts_line=22, is_jump_target=True),
+  Instruction(opname='LOAD_GLOBAL', opcode=116, arg=2, argval='ZeroDivisionError', argrepr='ZeroDivisionError', offset=161, starts_line=None, is_jump_target=False),
+  Instruction(opname='COMPARE_OP', opcode=107, arg=10, argval='exception match', argrepr='exception match', offset=164, starts_line=None, is_jump_target=False),
+  Instruction(opname='POP_JUMP_IF_FALSE', opcode=114, arg=187, argval=187, argrepr='', offset=167, starts_line=None, is_jump_target=False),
+  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=170, starts_line=None, is_jump_target=False),
+  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=171, starts_line=None, is_jump_target=False),
+  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=172, starts_line=None, is_jump_target=False),
+  Instruction(opname='LOAD_GLOBAL', opcode=116, arg=1, argval='print', argrepr='print', offset=173, starts_line=23, is_jump_target=False),
+  Instruction(opname='LOAD_CONST', opcode=100, arg=8, argval='Here we go, here we go, here we go...', argrepr="'Here we go, here we go, here we go...'", offset=176, starts_line=None, is_jump_target=False),
+  Instruction(opname='CALL_FUNCTION', opcode=131, arg=1, argval=1, argrepr='1 positional, 0 keyword pair', offset=179, starts_line=None, is_jump_target=False),
   Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=182, starts_line=None, is_jump_target=False),
-  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=183, starts_line=None, is_jump_target=False),
-  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=184, starts_line=None, is_jump_target=False),
-  Instruction(opname='LOAD_GLOBAL', opcode=116, arg=1, argval='print', argrepr='print', offset=185, starts_line=23, is_jump_target=False),
-  Instruction(opname='LOAD_CONST', opcode=100, arg=8, argval='Here we go, here we go, here we go...', argrepr="'Here we go, here we go, here we go...'", offset=188, starts_line=None, is_jump_target=False),
-  Instruction(opname='CALL_FUNCTION', opcode=131, arg=1, argval=1, argrepr='1 positional, 0 keyword pair', offset=191, starts_line=None, is_jump_target=False),
-  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=194, starts_line=None, is_jump_target=False),
-  Instruction(opname='POP_EXCEPT', opcode=89, arg=None, argval=None, argrepr='', offset=195, starts_line=None, is_jump_target=False),
-  Instruction(opname='JUMP_FORWARD', opcode=110, arg=26, argval=225, argrepr='to 225', offset=196, starts_line=None, is_jump_target=False),
-  Instruction(opname='END_FINALLY', opcode=88, arg=None, argval=None, argrepr='', offset=199, starts_line=None, is_jump_target=True),
-  Instruction(opname='LOAD_FAST', opcode=124, arg=0, argval='i', argrepr='i', offset=200, starts_line=25, is_jump_target=True),
-  Instruction(opname='SETUP_WITH', opcode=143, arg=17, argval=223, argrepr='to 223', offset=203, starts_line=None, is_jump_target=False),
-  Instruction(opname='STORE_FAST', opcode=125, arg=1, argval='dodgy', argrepr='dodgy', offset=206, starts_line=None, is_jump_target=False),
-  Instruction(opname='LOAD_GLOBAL', opcode=116, arg=1, argval='print', argrepr='print', offset=209, starts_line=26, is_jump_target=False),
-  Instruction(opname='LOAD_CONST', opcode=100, arg=9, argval='Never reach this', argrepr="'Never reach this'", offset=212, starts_line=None, is_jump_target=False),
-  Instruction(opname='CALL_FUNCTION', opcode=131, arg=1, argval=1, argrepr='1 positional, 0 keyword pair', offset=215, starts_line=None, is_jump_target=False),
-  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=218, starts_line=None, is_jump_target=False),
-  Instruction(opname='POP_BLOCK', opcode=87, arg=None, argval=None, argrepr='', offset=219, starts_line=None, is_jump_target=False),
-  Instruction(opname='LOAD_CONST', opcode=100, arg=0, argval=None, argrepr='None', offset=220, starts_line=None, is_jump_target=False),
-  Instruction(opname='WITH_CLEANUP', opcode=81, arg=None, argval=None, argrepr='', offset=223, starts_line=None, is_jump_target=True),
-  Instruction(opname='END_FINALLY', opcode=88, arg=None, argval=None, argrepr='', offset=224, starts_line=None, is_jump_target=False),
-  Instruction(opname='POP_BLOCK', opcode=87, arg=None, argval=None, argrepr='', offset=225, starts_line=None, is_jump_target=True),
-  Instruction(opname='LOAD_CONST', opcode=100, arg=0, argval=None, argrepr='None', offset=226, starts_line=None, is_jump_target=False),
-  Instruction(opname='LOAD_GLOBAL', opcode=116, arg=1, argval='print', argrepr='print', offset=229, starts_line=28, is_jump_target=True),
-  Instruction(opname='LOAD_CONST', opcode=100, arg=10, argval="OK, now we're done", argrepr='"OK, now we\'re done"', offset=232, starts_line=None, is_jump_target=False),
-  Instruction(opname='CALL_FUNCTION', opcode=131, arg=1, argval=1, argrepr='1 positional, 0 keyword pair', offset=235, starts_line=None, is_jump_target=False),
-  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=238, starts_line=None, is_jump_target=False),
-  Instruction(opname='END_FINALLY', opcode=88, arg=None, argval=None, argrepr='', offset=239, starts_line=None, is_jump_target=False),
-  Instruction(opname='LOAD_CONST', opcode=100, arg=0, argval=None, argrepr='None', offset=240, starts_line=None, is_jump_target=False),
-  Instruction(opname='RETURN_VALUE', opcode=83, arg=None, argval=None, argrepr='', offset=243, starts_line=None, is_jump_target=False),
+  Instruction(opname='POP_EXCEPT', opcode=89, arg=None, argval=None, argrepr='', offset=183, starts_line=None, is_jump_target=False),
+  Instruction(opname='JUMP_FORWARD', opcode=110, arg=26, argval=213, argrepr='to 213', offset=184, starts_line=None, is_jump_target=False),
+  Instruction(opname='END_FINALLY', opcode=88, arg=None, argval=None, argrepr='', offset=187, starts_line=None, is_jump_target=True),
+  Instruction(opname='LOAD_FAST', opcode=124, arg=0, argval='i', argrepr='i', offset=188, starts_line=25, is_jump_target=True),
+  Instruction(opname='SETUP_WITH', opcode=143, arg=17, argval=211, argrepr='to 211', offset=191, starts_line=None, is_jump_target=False),
+  Instruction(opname='STORE_FAST', opcode=125, arg=1, argval='dodgy', argrepr='dodgy', offset=194, starts_line=None, is_jump_target=False),
+  Instruction(opname='LOAD_GLOBAL', opcode=116, arg=1, argval='print', argrepr='print', offset=197, starts_line=26, is_jump_target=False),
+  Instruction(opname='LOAD_CONST', opcode=100, arg=9, argval='Never reach this', argrepr="'Never reach this'", offset=200, starts_line=None, is_jump_target=False),
+  Instruction(opname='CALL_FUNCTION', opcode=131, arg=1, argval=1, argrepr='1 positional, 0 keyword pair', offset=203, starts_line=None, is_jump_target=False),
+  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=206, starts_line=None, is_jump_target=False),
+  Instruction(opname='POP_BLOCK', opcode=87, arg=None, argval=None, argrepr='', offset=207, starts_line=None, is_jump_target=False),
+  Instruction(opname='LOAD_CONST', opcode=100, arg=0, argval=None, argrepr='None', offset=208, starts_line=None, is_jump_target=False),
+  Instruction(opname='WITH_CLEANUP', opcode=81, arg=None, argval=None, argrepr='', offset=211, starts_line=None, is_jump_target=True),
+  Instruction(opname='END_FINALLY', opcode=88, arg=None, argval=None, argrepr='', offset=212, starts_line=None, is_jump_target=False),
+  Instruction(opname='POP_BLOCK', opcode=87, arg=None, argval=None, argrepr='', offset=213, starts_line=None, is_jump_target=True),
+  Instruction(opname='LOAD_CONST', opcode=100, arg=0, argval=None, argrepr='None', offset=214, starts_line=None, is_jump_target=False),
+  Instruction(opname='LOAD_GLOBAL', opcode=116, arg=1, argval='print', argrepr='print', offset=217, starts_line=28, is_jump_target=True),
+  Instruction(opname='LOAD_CONST', opcode=100, arg=10, argval="OK, now we're done", argrepr='"OK, now we\'re done"', offset=220, starts_line=None, is_jump_target=False),
+  Instruction(opname='CALL_FUNCTION', opcode=131, arg=1, argval=1, argrepr='1 positional, 0 keyword pair', offset=223, starts_line=None, is_jump_target=False),
+  Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=226, starts_line=None, is_jump_target=False),
+  Instruction(opname='END_FINALLY', opcode=88, arg=None, argval=None, argrepr='', offset=227, starts_line=None, is_jump_target=False),
+  Instruction(opname='LOAD_CONST', opcode=100, arg=0, argval=None, argrepr='None', offset=228, starts_line=None, is_jump_target=False),
+  Instruction(opname='RETURN_VALUE', opcode=83, arg=None, argval=None, argrepr='', offset=231, starts_line=None, is_jump_target=False),
 ]
 
 # One last piece of inspect fodder to check the default line number handling
diff --git a/Lib/test/test_doctest.py b/Lib/test/test_doctest.py
index 4137d5aa0b..95700a3d3f 100644
--- a/Lib/test/test_doctest.py
+++ b/Lib/test/test_doctest.py
@@ -4,6 +4,7 @@ Test script for doctest.
 
 from test import support
 import doctest
+import functools
 import os
 import sys
 
@@ -434,7 +435,7 @@ We'll simulate a __file__ attr that ends in pyc:
     >>> tests = finder.find(sample_func)
 
     >>> print(tests)  # doctest: +ELLIPSIS
-    [<DocTest sample_func from ...:18 (1 example)>]
+    [<DocTest sample_func from ...:19 (1 example)>]
 
 The exact name depends on how test_doctest was invoked, so allow for
 leading path components.
@@ -2096,22 +2097,9 @@ def test_DocTestSuite():
          >>> suite.run(unittest.TestResult())
          <unittest.result.TestResult run=0 errors=0 failures=0>
 
-       However, if DocTestSuite finds no docstrings, it raises an error:
+       The module need not contain any docstrings either:
 
-         >>> try:
-         ...     doctest.DocTestSuite('test.sample_doctest_no_docstrings')
-         ... except ValueError as e:
-         ...     error = e
-
-         >>> print(error.args[1])
-         has no docstrings
-
-       You can prevent this error by passing a DocTestFinder instance with
-       the `exclude_empty` keyword argument set to False:
-
-         >>> finder = doctest.DocTestFinder(exclude_empty=False)
-         >>> suite = doctest.DocTestSuite('test.sample_doctest_no_docstrings',
-         ...                              test_finder=finder)
+         >>> suite = doctest.DocTestSuite('test.sample_doctest_no_docstrings')
          >>> suite.run(unittest.TestResult())
          <unittest.result.TestResult run=0 errors=0 failures=0>
 
@@ -2121,6 +2109,22 @@ def test_DocTestSuite():
          >>> suite.run(unittest.TestResult())
          <unittest.result.TestResult run=9 errors=0 failures=4>
 
+       We can also provide a DocTestFinder:
+
+         >>> finder = doctest.DocTestFinder()
+         >>> suite = doctest.DocTestSuite('test.sample_doctest',
+         ...                          test_finder=finder)
+         >>> suite.run(unittest.TestResult())
+         <unittest.result.TestResult run=9 errors=0 failures=4>
+
+       The DocTestFinder need not return any tests:
+
+         >>> finder = doctest.DocTestFinder()
+         >>> suite = doctest.DocTestSuite('test.sample_doctest_no_docstrings',
+         ...                          test_finder=finder)
+         >>> suite.run(unittest.TestResult())
+         <unittest.result.TestResult run=0 errors=0 failures=0>
+
        We can supply global variables.  If we pass globs, they will be
        used instead of the module globals.  Here we'll pass an empty
        globals, triggering an extra error:
@@ -2168,7 +2172,7 @@ def test_DocTestSuite():
          >>> test.test_doctest.sillySetup
          Traceback (most recent call last):
          ...
-         AttributeError: 'module' object has no attribute 'sillySetup'
+         AttributeError: module 'test.test_doctest' has no attribute 'sillySetup'
 
        The setUp and tearDown funtions are passed test objects. Here
        we'll use the setUp function to supply the missing variable y:
@@ -2314,7 +2318,7 @@ def test_DocFileSuite():
          >>> test.test_doctest.sillySetup
          Traceback (most recent call last):
          ...
-         AttributeError: 'module' object has no attribute 'sillySetup'
+         AttributeError: module 'test.test_doctest' has no attribute 'sillySetup'
 
        The setUp and tearDown funtions are passed test objects.
        Here, we'll use a setUp function to set the favorite color in
@@ -2361,6 +2365,22 @@ def test_trailing_space_in_test():
       foo \n
     """
 
+class Wrapper:
+    def __init__(self, func):
+        self.func = func
+        functools.update_wrapper(self, func)
+
+    def __call__(self, *args, **kwargs):
+        self.func(*args, **kwargs)
+
+@Wrapper
+def test_look_in_unwrapped():
+    """
+    Docstrings in wrapped functions must be detected as well.
+
+    >>> 'one other test'
+    'one other test'
+    """
 
 def test_unittest_reportflags():
     """Default unittest reporting flags can be set to control reporting
@@ -2927,7 +2947,7 @@ Invalid doctest option:
 
 def test_main():
     # Check the doctest cases in doctest itself:
-    support.run_doctest(doctest, verbosity=True)
+    ret = support.run_doctest(doctest, verbosity=True)
     # Check the doctest cases defined here:
     from test import test_doctest
     support.run_doctest(test_doctest, verbosity=True)
diff --git a/Lib/test/test_docxmlrpc.py b/Lib/test/test_docxmlrpc.py
index 06161f23dd..d9fd9170bb 100644
--- a/Lib/test/test_docxmlrpc.py
+++ b/Lib/test/test_docxmlrpc.py
@@ -87,10 +87,11 @@ class DocXMLRPCHTTPGETServer(unittest.TestCase):
         threading.Thread(target=server, args=(self.evt, 1)).start()
 
         # wait for port to be assigned
-        n = 1000
-        while n > 0 and PORT is None:
-            time.sleep(0.001)
-            n -= 1
+        deadline = time.monotonic() + 10.0
+        while PORT is None:
+            time.sleep(0.010)
+            if time.monotonic() > deadline:
+                break
 
         self.client = http.client.HTTPConnection("localhost:%d" % PORT)
 
diff --git a/Lib/test/test_eintr.py b/Lib/test/test_eintr.py
new file mode 100644
index 0000000000..8b5f5070e6
--- /dev/null
+++ b/Lib/test/test_eintr.py
@@ -0,0 +1,20 @@
+import os
+import signal
+import unittest
+
+from test import script_helper, support
+
+
+@unittest.skipUnless(os.name == "posix", "only supported on Unix")
+class EINTRTests(unittest.TestCase):
+
+    @unittest.skipUnless(hasattr(signal, "setitimer"), "requires setitimer()")
+    def test_all(self):
+        # Run the tester in a sub-process, to make sure there is only one
+        # thread (for reliable signal delivery).
+        tester = support.findfile("eintr_tester.py", subdir="eintrdata")
+        script_helper.assert_python_ok(tester)
+
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/Lib/test/test_email/test_email.py b/Lib/test/test_email/test_email.py
index 227110ffb1..218ce0ce81 100644
--- a/Lib/test/test_email/test_email.py
+++ b/Lib/test/test_email/test_email.py
@@ -1636,6 +1636,10 @@ class TestMIMEText(unittest.TestCase):
         msg = MIMEText('hello there', _charset='us-ascii')
         eq(msg.get_charset().input_charset, 'us-ascii')
         eq(msg['content-type'], 'text/plain; charset="us-ascii"')
+        # Also accept a Charset instance
+        msg = MIMEText('hello there', _charset=Charset('utf-8'))
+        eq(msg.get_charset().input_charset, 'utf-8')
+        eq(msg['content-type'], 'text/plain; charset="utf-8"')
 
     def test_7bit_input(self):
         eq = self.assertEqual
diff --git a/Lib/test/test_email/test_message.py b/Lib/test/test_email/test_message.py
index 50e1a632c2..d78049e315 100644
--- a/Lib/test/test_email/test_message.py
+++ b/Lib/test/test_email/test_message.py
@@ -723,24 +723,14 @@ class TestEmailMessageBase:
     def test_is_attachment(self):
         m = self._make_message()
         self.assertFalse(m.is_attachment())
-        with self.assertWarns(DeprecationWarning):
-            self.assertFalse(m.is_attachment)
         m['Content-Disposition'] = 'inline'
         self.assertFalse(m.is_attachment())
-        with self.assertWarns(DeprecationWarning):
-            self.assertFalse(m.is_attachment)
         m.replace_header('Content-Disposition', 'attachment')
         self.assertTrue(m.is_attachment())
-        with self.assertWarns(DeprecationWarning):
-            self.assertTrue(m.is_attachment)
         m.replace_header('Content-Disposition', 'AtTachMent')
         self.assertTrue(m.is_attachment())
-        with self.assertWarns(DeprecationWarning):
-            self.assertTrue(m.is_attachment)
         m.set_param('filename', 'abc.png', 'Content-Disposition')
         self.assertTrue(m.is_attachment())
-        with self.assertWarns(DeprecationWarning):
-            self.assertTrue(m.is_attachment)
 
 
 class TestEmailMessage(TestEmailMessageBase, TestEmailBase):
diff --git a/Lib/test/test_enum.py b/Lib/test/test_enum.py
index dccaa4ffaa..7d172c86e4 100644
--- a/Lib/test/test_enum.py
+++ b/Lib/test/test_enum.py
@@ -646,6 +646,23 @@ class TestEnum(unittest.TestCase):
             self.assertIn(e, SummerMonth)
             self.assertIs(type(e), SummerMonth)
 
+    def test_programatic_function_string_with_start(self):
+        SummerMonth = Enum('SummerMonth', 'june july august', start=10)
+        lst = list(SummerMonth)
+        self.assertEqual(len(lst), len(SummerMonth))
+        self.assertEqual(len(SummerMonth), 3, SummerMonth)
+        self.assertEqual(
+                [SummerMonth.june, SummerMonth.july, SummerMonth.august],
+                lst,
+                )
+        for i, month in enumerate('june july august'.split(), 10):
+            e = SummerMonth(i)
+            self.assertEqual(int(e.value), i)
+            self.assertNotEqual(e, i)
+            self.assertEqual(e.name, month)
+            self.assertIn(e, SummerMonth)
+            self.assertIs(type(e), SummerMonth)
+
     def test_programatic_function_string_list(self):
         SummerMonth = Enum('SummerMonth', ['june', 'july', 'august'])
         lst = list(SummerMonth)
@@ -663,6 +680,23 @@ class TestEnum(unittest.TestCase):
             self.assertIn(e, SummerMonth)
             self.assertIs(type(e), SummerMonth)
 
+    def test_programatic_function_string_list_with_start(self):
+        SummerMonth = Enum('SummerMonth', ['june', 'july', 'august'], start=20)
+        lst = list(SummerMonth)
+        self.assertEqual(len(lst), len(SummerMonth))
+        self.assertEqual(len(SummerMonth), 3, SummerMonth)
+        self.assertEqual(
+                [SummerMonth.june, SummerMonth.july, SummerMonth.august],
+                lst,
+                )
+        for i, month in enumerate('june july august'.split(), 20):
+            e = SummerMonth(i)
+            self.assertEqual(int(e.value), i)
+            self.assertNotEqual(e, i)
+            self.assertEqual(e.name, month)
+            self.assertIn(e, SummerMonth)
+            self.assertIs(type(e), SummerMonth)
+
     def test_programatic_function_iterable(self):
         SummerMonth = Enum(
                 'SummerMonth',
@@ -719,6 +753,22 @@ class TestEnum(unittest.TestCase):
             self.assertIn(e, SummerMonth)
             self.assertIs(type(e), SummerMonth)
 
+    def test_programatic_function_type_with_start(self):
+        SummerMonth = Enum('SummerMonth', 'june july august', type=int, start=30)
+        lst = list(SummerMonth)
+        self.assertEqual(len(lst), len(SummerMonth))
+        self.assertEqual(len(SummerMonth), 3, SummerMonth)
+        self.assertEqual(
+                [SummerMonth.june, SummerMonth.july, SummerMonth.august],
+                lst,
+                )
+        for i, month in enumerate('june july august'.split(), 30):
+            e = SummerMonth(i)
+            self.assertEqual(e, i)
+            self.assertEqual(e.name, month)
+            self.assertIn(e, SummerMonth)
+            self.assertIs(type(e), SummerMonth)
+
     def test_programatic_function_type_from_subclass(self):
         SummerMonth = IntEnum('SummerMonth', 'june july august')
         lst = list(SummerMonth)
@@ -735,6 +785,22 @@ class TestEnum(unittest.TestCase):
             self.assertIn(e, SummerMonth)
             self.assertIs(type(e), SummerMonth)
 
+    def test_programatic_function_type_from_subclass_with_start(self):
+        SummerMonth = IntEnum('SummerMonth', 'june july august', start=40)
+        lst = list(SummerMonth)
+        self.assertEqual(len(lst), len(SummerMonth))
+        self.assertEqual(len(SummerMonth), 3, SummerMonth)
+        self.assertEqual(
+                [SummerMonth.june, SummerMonth.july, SummerMonth.august],
+                lst,
+                )
+        for i, month in enumerate('june july august'.split(), 40):
+            e = SummerMonth(i)
+            self.assertEqual(e, i)
+            self.assertEqual(e.name, month)
+            self.assertIn(e, SummerMonth)
+            self.assertIs(type(e), SummerMonth)
+
     def test_subclassing(self):
         if isinstance(Name, Exception):
             raise Name
diff --git a/Lib/test/test_epoll.py b/Lib/test/test_epoll.py
index b37f033bf8..d72740376f 100644
--- a/Lib/test/test_epoll.py
+++ b/Lib/test/test_epoll.py
@@ -44,7 +44,7 @@ class TestEPoll(unittest.TestCase):
     def setUp(self):
         self.serverSocket = socket.socket()
         self.serverSocket.bind(('127.0.0.1', 0))
-        self.serverSocket.listen(1)
+        self.serverSocket.listen()
         self.connections = [self.serverSocket]
 
     def tearDown(self):
diff --git a/Lib/test/test_faulthandler.py b/Lib/test/test_faulthandler.py
index e68a09e181..35129b6a71 100644
--- a/Lib/test/test_faulthandler.py
+++ b/Lib/test/test_faulthandler.py
@@ -17,6 +17,10 @@ try:
     HAVE_THREADS = True
 except ImportError:
     HAVE_THREADS = False
+try:
+    import _testcapi
+except ImportError:
+    _testcapi = None
 
 TIMEOUT = 0.5
 
@@ -135,26 +139,32 @@ class FaultHandlerTests(unittest.TestCase):
             3,
             'Floating point exception')
 
-    @unittest.skipIf(not hasattr(faulthandler, '_sigbus'),
-                     "need faulthandler._sigbus()")
+    @unittest.skipIf(_testcapi is None, 'need _testcapi')
+    @unittest.skipUnless(hasattr(signal, 'SIGBUS'), 'need signal.SIGBUS')
     def test_sigbus(self):
         self.check_fatal_error("""
+            import _testcapi
             import faulthandler
+            import signal
+
             faulthandler.enable()
-            faulthandler._sigbus()
+            _testcapi.raise_signal(signal.SIGBUS)
             """,
-            3,
+            6,
             'Bus error')
 
-    @unittest.skipIf(not hasattr(faulthandler, '_sigill'),
-                     "need faulthandler._sigill()")
+    @unittest.skipIf(_testcapi is None, 'need _testcapi')
+    @unittest.skipUnless(hasattr(signal, 'SIGILL'), 'need signal.SIGILL')
     def test_sigill(self):
         self.check_fatal_error("""
+            import _testcapi
             import faulthandler
+            import signal
+
             faulthandler.enable()
-            faulthandler._sigill()
+            _testcapi.raise_signal(signal.SIGILL)
             """,
-            3,
+            6,
             'Illegal instruction')
 
     def test_fatal_error(self):
diff --git a/Lib/test/test_fileio.py b/Lib/test/test_fileio.py
index c37482ed70..743ca5c73c 100644
--- a/Lib/test/test_fileio.py
+++ b/Lib/test/test_fileio.py
@@ -60,6 +60,15 @@ class AutoFileTests(unittest.TestCase):
             self.assertRaises((AttributeError, TypeError),
                               setattr, f, attr, 'oops')
 
+    def testBlksize(self):
+        # test private _blksize attribute
+        blksize = io.DEFAULT_BUFFER_SIZE
+        # try to get preferred blksize from stat.st_blksize, if available
+        if hasattr(os, 'fstat'):
+            fst = os.fstat(self.f.fileno())
+            blksize = getattr(fst, 'st_blksize', blksize)
+        self.assertEqual(self.f._blksize, blksize)
+
     def testReadinto(self):
         # verify readinto
         self.f.write(bytes([1, 2]))
@@ -103,14 +112,26 @@ class AutoFileTests(unittest.TestCase):
         self.assertRaises(TypeError, self.f.write, "Hello!")
 
     def testRepr(self):
-        self.assertEqual(repr(self.f), "<_io.FileIO name=%r mode=%r>"
-                                        % (self.f.name, self.f.mode))
+        self.assertEqual(
+            repr(self.f), "<_io.FileIO name=%r mode=%r closefd=True>"
+                          % (self.f.name, self.f.mode))
         del self.f.name
-        self.assertEqual(repr(self.f), "<_io.FileIO fd=%r mode=%r>"
-                                        % (self.f.fileno(), self.f.mode))
+        self.assertEqual(
+            repr(self.f), "<_io.FileIO fd=%r mode=%r closefd=True>"
+                          % (self.f.fileno(), self.f.mode))
         self.f.close()
         self.assertEqual(repr(self.f), "<_io.FileIO [closed]>")
 
+    def testReprNoCloseFD(self):
+        fd = os.open(TESTFN, os.O_RDONLY)
+        try:
+            with _FileIO(fd, 'r', closefd=False) as f:
+                self.assertEqual(repr(f),
+                                 "<_io.FileIO name=%r mode=%r closefd=False>"
+                                 % (f.name, f.mode))
+        finally:
+            os.close(fd)
+
     def testErrors(self):
         f = self.f
         self.assertTrue(not f.isatty())
@@ -141,7 +162,7 @@ class AutoFileTests(unittest.TestCase):
     def testOpendir(self):
         # Issue 3703: opening a directory should fill the errno
         # Windows always returns "[Errno 13]: Permission denied
-        # Unix calls dircheck() and returns "[Errno 21]: Is a directory"
+        # Unix uses fstat and returns "[Errno 21]: Is a directory"
         try:
             _FileIO('.', 'r')
         except OSError as e:
@@ -352,8 +373,8 @@ class OtherFileTests(unittest.TestCase):
 
     def testConstructorHandlesNULChars(self):
         fn_with_NUL = 'foo\0bar'
-        self.assertRaises(TypeError, _FileIO, fn_with_NUL, 'w')
-        self.assertRaises(TypeError, _FileIO, bytes(fn_with_NUL, 'ascii'), 'w')
+        self.assertRaises(ValueError, _FileIO, fn_with_NUL, 'w')
+        self.assertRaises(ValueError, _FileIO, bytes(fn_with_NUL, 'ascii'), 'w')
 
     def testInvalidFd(self):
         self.assertRaises(ValueError, _FileIO, -10)
diff --git a/Lib/test/test_fork1.py b/Lib/test/test_fork1.py
index e0626dffdc..8bcbd465cc 100644
--- a/Lib/test/test_fork1.py
+++ b/Lib/test/test_fork1.py
@@ -18,13 +18,14 @@ get_attribute(os, 'fork')
 
 class ForkTest(ForkWait):
     def wait_impl(self, cpid):
-        for i in range(10):
+        deadline = time.monotonic() + 10.0
+        while time.monotonic() <= deadline:
             # waitpid() shouldn't hang, but some of the buildbots seem to hang
             # in the forking tests.  This is an attempt to fix the problem.
             spid, status = os.waitpid(cpid, os.WNOHANG)
             if spid == cpid:
                 break
-            time.sleep(1.0)
+            time.sleep(0.1)
 
         self.assertEqual(spid, cpid)
         self.assertEqual(status, 0, "cause = %d, exit = %d" % (status&0xff, status>>8))
diff --git a/Lib/test/test_format.py b/Lib/test/test_format.py
index fc71e4818e..9d1f5d3302 100644
--- a/Lib/test/test_format.py
+++ b/Lib/test/test_format.py
@@ -9,7 +9,7 @@ maxsize = support.MAX_Py_ssize_t
 # test string formatting operator (I am not sure if this is being tested
 # elsewhere but, surely, some of the given cases are *not* tested because
 # they crash python)
-# test on unicode strings as well
+# test on bytes object as well
 
 def testformat(formatstr, args, output=None, limit=None, overflowok=False):
     if verbose:
@@ -46,191 +46,209 @@ def testformat(formatstr, args, output=None, limit=None, overflowok=False):
             if verbose:
                 print('yes')
 
+def testcommon(formatstr, args, output=None, limit=None, overflowok=False):
+    # if formatstr is a str, test str, bytes, and bytearray;
+    # otherwise, test bytes and bytearry
+    if isinstance(formatstr, str):
+        testformat(formatstr, args, output, limit, overflowok)
+        b_format = formatstr.encode('ascii')
+    else:
+        b_format = formatstr
+    ba_format = bytearray(b_format)
+    b_args = []
+    if not isinstance(args, tuple):
+        args = (args, )
+    b_args = tuple(args)
+    if output is None:
+        b_output = ba_output = None
+    else:
+        if isinstance(output, str):
+            b_output = output.encode('ascii')
+        else:
+            b_output = output
+        ba_output = bytearray(b_output)
+    testformat(b_format, b_args, b_output, limit, overflowok)
+    testformat(ba_format, b_args, ba_output, limit, overflowok)
+
 
 class FormatTest(unittest.TestCase):
-    def test_format(self):
-        testformat("%.1d", (1,), "1")
-        testformat("%.*d", (sys.maxsize,1), overflowok=True)  # expect overflow
-        testformat("%.100d", (1,), '00000000000000000000000000000000000000'
+
+    def test_common_format(self):
+        # test the format identifiers that work the same across
+        # str, bytes, and bytearrays (integer, float, oct, hex)
+        testcommon("%.1d", (1,), "1")
+        testcommon("%.*d", (sys.maxsize,1), overflowok=True)  # expect overflow
+        testcommon("%.100d", (1,), '00000000000000000000000000000000000000'
                  '000000000000000000000000000000000000000000000000000000'
                  '00000001', overflowok=True)
-        testformat("%#.117x", (1,), '0x00000000000000000000000000000000000'
+        testcommon("%#.117x", (1,), '0x00000000000000000000000000000000000'
                  '000000000000000000000000000000000000000000000000000000'
                  '0000000000000000000000000001',
                  overflowok=True)
-        testformat("%#.118x", (1,), '0x00000000000000000000000000000000000'
+        testcommon("%#.118x", (1,), '0x00000000000000000000000000000000000'
                  '000000000000000000000000000000000000000000000000000000'
                  '00000000000000000000000000001',
                  overflowok=True)
 
-        testformat("%f", (1.0,), "1.000000")
+        testcommon("%f", (1.0,), "1.000000")
         # these are trying to test the limits of the internal magic-number-length
         # formatting buffer, if that number changes then these tests are less
         # effective
-        testformat("%#.*g", (109, -1.e+49/3.))
-        testformat("%#.*g", (110, -1.e+49/3.))
-        testformat("%#.*g", (110, -1.e+100/3.))
+        testcommon("%#.*g", (109, -1.e+49/3.))
+        testcommon("%#.*g", (110, -1.e+49/3.))
+        testcommon("%#.*g", (110, -1.e+100/3.))
         # test some ridiculously large precision, expect overflow
-        testformat('%12.*f', (123456, 1.0))
+        testcommon('%12.*f', (123456, 1.0))
 
         # check for internal overflow validation on length of precision
         # these tests should no longer cause overflow in Python
         # 2.7/3.1 and later.
-        testformat("%#.*g", (110, -1.e+100/3.))
-        testformat("%#.*G", (110, -1.e+100/3.))
-        testformat("%#.*f", (110, -1.e+100/3.))
-        testformat("%#.*F", (110, -1.e+100/3.))
+        testcommon("%#.*g", (110, -1.e+100/3.))
+        testcommon("%#.*G", (110, -1.e+100/3.))
+        testcommon("%#.*f", (110, -1.e+100/3.))
+        testcommon("%#.*F", (110, -1.e+100/3.))
         # Formatting of integers. Overflow is not ok
-        testformat("%x", 10, "a")
-        testformat("%x", 100000000000, "174876e800")
-        testformat("%o", 10, "12")
-        testformat("%o", 100000000000, "1351035564000")
-        testformat("%d", 10, "10")
-        testformat("%d", 100000000000, "100000000000")
+        testcommon("%x", 10, "a")
+        testcommon("%x", 100000000000, "174876e800")
+        testcommon("%o", 10, "12")
+        testcommon("%o", 100000000000, "1351035564000")
+        testcommon("%d", 10, "10")
+        testcommon("%d", 100000000000, "100000000000")
         big = 123456789012345678901234567890
-        testformat("%d", big, "123456789012345678901234567890")
-        testformat("%d", -big, "-123456789012345678901234567890")
-        testformat("%5d", -big, "-123456789012345678901234567890")
-        testformat("%31d", -big, "-123456789012345678901234567890")
-        testformat("%32d", -big, " -123456789012345678901234567890")
-        testformat("%-32d", -big, "-123456789012345678901234567890 ")
-        testformat("%032d", -big, "-0123456789012345678901234567890")
-        testformat("%-032d", -big, "-123456789012345678901234567890 ")
-        testformat("%034d", -big, "-000123456789012345678901234567890")
-        testformat("%034d", big, "0000123456789012345678901234567890")
-        testformat("%0+34d", big, "+000123456789012345678901234567890")
-        testformat("%+34d", big, "   +123456789012345678901234567890")
-        testformat("%34d", big, "    123456789012345678901234567890")
-        testformat("%.2d", big, "123456789012345678901234567890")
-        testformat("%.30d", big, "123456789012345678901234567890")
-        testformat("%.31d", big, "0123456789012345678901234567890")
-        testformat("%32.31d", big, " 0123456789012345678901234567890")
-        testformat("%d", float(big), "123456________________________", 6)
+        testcommon("%d", big, "123456789012345678901234567890")
+        testcommon("%d", -big, "-123456789012345678901234567890")
+        testcommon("%5d", -big, "-123456789012345678901234567890")
+        testcommon("%31d", -big, "-123456789012345678901234567890")
+        testcommon("%32d", -big, " -123456789012345678901234567890")
+        testcommon("%-32d", -big, "-123456789012345678901234567890 ")
+        testcommon("%032d", -big, "-0123456789012345678901234567890")
+        testcommon("%-032d", -big, "-123456789012345678901234567890 ")
+        testcommon("%034d", -big, "-000123456789012345678901234567890")
+        testcommon("%034d", big, "0000123456789012345678901234567890")
+        testcommon("%0+34d", big, "+000123456789012345678901234567890")
+        testcommon("%+34d", big, "   +123456789012345678901234567890")
+        testcommon("%34d", big, "    123456789012345678901234567890")
+        testcommon("%.2d", big, "123456789012345678901234567890")
+        testcommon("%.30d", big, "123456789012345678901234567890")
+        testcommon("%.31d", big, "0123456789012345678901234567890")
+        testcommon("%32.31d", big, " 0123456789012345678901234567890")
+        testcommon("%d", float(big), "123456________________________", 6)
         big = 0x1234567890abcdef12345  # 21 hex digits
-        testformat("%x", big, "1234567890abcdef12345")
-        testformat("%x", -big, "-1234567890abcdef12345")
-        testformat("%5x", -big, "-1234567890abcdef12345")
-        testformat("%22x", -big, "-1234567890abcdef12345")
-        testformat("%23x", -big, " -1234567890abcdef12345")
-        testformat("%-23x", -big, "-1234567890abcdef12345 ")
-        testformat("%023x", -big, "-01234567890abcdef12345")
-        testformat("%-023x", -big, "-1234567890abcdef12345 ")
-        testformat("%025x", -big, "-0001234567890abcdef12345")
-        testformat("%025x", big, "00001234567890abcdef12345")
-        testformat("%0+25x", big, "+0001234567890abcdef12345")
-        testformat("%+25x", big, "   +1234567890abcdef12345")
-        testformat("%25x", big, "    1234567890abcdef12345")
-        testformat("%.2x", big, "1234567890abcdef12345")
-        testformat("%.21x", big, "1234567890abcdef12345")
-        testformat("%.22x", big, "01234567890abcdef12345")
-        testformat("%23.22x", big, " 01234567890abcdef12345")
-        testformat("%-23.22x", big, "01234567890abcdef12345 ")
-        testformat("%X", big, "1234567890ABCDEF12345")
-        testformat("%#X", big, "0X1234567890ABCDEF12345")
-        testformat("%#x", big, "0x1234567890abcdef12345")
-        testformat("%#x", -big, "-0x1234567890abcdef12345")
-        testformat("%#.23x", -big, "-0x001234567890abcdef12345")
-        testformat("%#+.23x", big, "+0x001234567890abcdef12345")
-        testformat("%# .23x", big, " 0x001234567890abcdef12345")
-        testformat("%#+.23X", big, "+0X001234567890ABCDEF12345")
-        testformat("%#-+.23X", big, "+0X001234567890ABCDEF12345")
-        testformat("%#-+26.23X", big, "+0X001234567890ABCDEF12345")
-        testformat("%#-+27.23X", big, "+0X001234567890ABCDEF12345 ")
-        testformat("%#+27.23X", big, " +0X001234567890ABCDEF12345")
+        testcommon("%x", big, "1234567890abcdef12345")
+        testcommon("%x", -big, "-1234567890abcdef12345")
+        testcommon("%5x", -big, "-1234567890abcdef12345")
+        testcommon("%22x", -big, "-1234567890abcdef12345")
+        testcommon("%23x", -big, " -1234567890abcdef12345")
+        testcommon("%-23x", -big, "-1234567890abcdef12345 ")
+        testcommon("%023x", -big, "-01234567890abcdef12345")
+        testcommon("%-023x", -big, "-1234567890abcdef12345 ")
+        testcommon("%025x", -big, "-0001234567890abcdef12345")
+        testcommon("%025x", big, "00001234567890abcdef12345")
+        testcommon("%0+25x", big, "+0001234567890abcdef12345")
+        testcommon("%+25x", big, "   +1234567890abcdef12345")
+        testcommon("%25x", big, "    1234567890abcdef12345")
+        testcommon("%.2x", big, "1234567890abcdef12345")
+        testcommon("%.21x", big, "1234567890abcdef12345")
+        testcommon("%.22x", big, "01234567890abcdef12345")
+        testcommon("%23.22x", big, " 01234567890abcdef12345")
+        testcommon("%-23.22x", big, "01234567890abcdef12345 ")
+        testcommon("%X", big, "1234567890ABCDEF12345")
+        testcommon("%#X", big, "0X1234567890ABCDEF12345")
+        testcommon("%#x", big, "0x1234567890abcdef12345")
+        testcommon("%#x", -big, "-0x1234567890abcdef12345")
+        testcommon("%#.23x", -big, "-0x001234567890abcdef12345")
+        testcommon("%#+.23x", big, "+0x001234567890abcdef12345")
+        testcommon("%# .23x", big, " 0x001234567890abcdef12345")
+        testcommon("%#+.23X", big, "+0X001234567890ABCDEF12345")
+        testcommon("%#-+.23X", big, "+0X001234567890ABCDEF12345")
+        testcommon("%#-+26.23X", big, "+0X001234567890ABCDEF12345")
+        testcommon("%#-+27.23X", big, "+0X001234567890ABCDEF12345 ")
+        testcommon("%#+27.23X", big, " +0X001234567890ABCDEF12345")
         # next one gets two leading zeroes from precision, and another from the
         # 0 flag and the width
-        testformat("%#+027.23X", big, "+0X0001234567890ABCDEF12345")
+        testcommon("%#+027.23X", big, "+0X0001234567890ABCDEF12345")
         # same, except no 0 flag
-        testformat("%#+27.23X", big, " +0X001234567890ABCDEF12345")
-        with self.assertWarns(DeprecationWarning):
-            testformat("%x", float(big), "123456_______________", 6)
+        testcommon("%#+27.23X", big, " +0X001234567890ABCDEF12345")
         big = 0o12345670123456701234567012345670  # 32 octal digits
-        testformat("%o", big, "12345670123456701234567012345670")
-        testformat("%o", -big, "-12345670123456701234567012345670")
-        testformat("%5o", -big, "-12345670123456701234567012345670")
-        testformat("%33o", -big, "-12345670123456701234567012345670")
-        testformat("%34o", -big, " -12345670123456701234567012345670")
-        testformat("%-34o", -big, "-12345670123456701234567012345670 ")
-        testformat("%034o", -big, "-012345670123456701234567012345670")
-        testformat("%-034o", -big, "-12345670123456701234567012345670 ")
-        testformat("%036o", -big, "-00012345670123456701234567012345670")
-        testformat("%036o", big, "000012345670123456701234567012345670")
-        testformat("%0+36o", big, "+00012345670123456701234567012345670")
-        testformat("%+36o", big, "   +12345670123456701234567012345670")
-        testformat("%36o", big, "    12345670123456701234567012345670")
-        testformat("%.2o", big, "12345670123456701234567012345670")
-        testformat("%.32o", big, "12345670123456701234567012345670")
-        testformat("%.33o", big, "012345670123456701234567012345670")
-        testformat("%34.33o", big, " 012345670123456701234567012345670")
-        testformat("%-34.33o", big, "012345670123456701234567012345670 ")
-        testformat("%o", big, "12345670123456701234567012345670")
-        testformat("%#o", big, "0o12345670123456701234567012345670")
-        testformat("%#o", -big, "-0o12345670123456701234567012345670")
-        testformat("%#.34o", -big, "-0o0012345670123456701234567012345670")
-        testformat("%#+.34o", big, "+0o0012345670123456701234567012345670")
-        testformat("%# .34o", big, " 0o0012345670123456701234567012345670")
-        testformat("%#+.34o", big, "+0o0012345670123456701234567012345670")
-        testformat("%#-+.34o", big, "+0o0012345670123456701234567012345670")
-        testformat("%#-+37.34o", big, "+0o0012345670123456701234567012345670")
-        testformat("%#+37.34o", big, "+0o0012345670123456701234567012345670")
+        testcommon("%o", big, "12345670123456701234567012345670")
+        testcommon("%o", -big, "-12345670123456701234567012345670")
+        testcommon("%5o", -big, "-12345670123456701234567012345670")
+        testcommon("%33o", -big, "-12345670123456701234567012345670")
+        testcommon("%34o", -big, " -12345670123456701234567012345670")
+        testcommon("%-34o", -big, "-12345670123456701234567012345670 ")
+        testcommon("%034o", -big, "-012345670123456701234567012345670")
+        testcommon("%-034o", -big, "-12345670123456701234567012345670 ")
+        testcommon("%036o", -big, "-00012345670123456701234567012345670")
+        testcommon("%036o", big, "000012345670123456701234567012345670")
+        testcommon("%0+36o", big, "+00012345670123456701234567012345670")
+        testcommon("%+36o", big, "   +12345670123456701234567012345670")
+        testcommon("%36o", big, "    12345670123456701234567012345670")
+        testcommon("%.2o", big, "12345670123456701234567012345670")
+        testcommon("%.32o", big, "12345670123456701234567012345670")
+        testcommon("%.33o", big, "012345670123456701234567012345670")
+        testcommon("%34.33o", big, " 012345670123456701234567012345670")
+        testcommon("%-34.33o", big, "012345670123456701234567012345670 ")
+        testcommon("%o", big, "12345670123456701234567012345670")
+        testcommon("%#o", big, "0o12345670123456701234567012345670")
+        testcommon("%#o", -big, "-0o12345670123456701234567012345670")
+        testcommon("%#.34o", -big, "-0o0012345670123456701234567012345670")
+        testcommon("%#+.34o", big, "+0o0012345670123456701234567012345670")
+        testcommon("%# .34o", big, " 0o0012345670123456701234567012345670")
+        testcommon("%#+.34o", big, "+0o0012345670123456701234567012345670")
+        testcommon("%#-+.34o", big, "+0o0012345670123456701234567012345670")
+        testcommon("%#-+37.34o", big, "+0o0012345670123456701234567012345670")
+        testcommon("%#+37.34o", big, "+0o0012345670123456701234567012345670")
         # next one gets one leading zero from precision
-        testformat("%.33o", big, "012345670123456701234567012345670")
+        testcommon("%.33o", big, "012345670123456701234567012345670")
         # base marker shouldn't change that, since "0" is redundant
-        testformat("%#.33o", big, "0o012345670123456701234567012345670")
+        testcommon("%#.33o", big, "0o012345670123456701234567012345670")
         # but reduce precision, and base marker should add a zero
-        testformat("%#.32o", big, "0o12345670123456701234567012345670")
+        testcommon("%#.32o", big, "0o12345670123456701234567012345670")
         # one leading zero from precision, and another from "0" flag & width
-        testformat("%034.33o", big, "0012345670123456701234567012345670")
+        testcommon("%034.33o", big, "0012345670123456701234567012345670")
         # base marker shouldn't change that
-        testformat("%0#34.33o", big, "0o012345670123456701234567012345670")
-        with self.assertWarns(DeprecationWarning):
-            testformat("%o", float(big), "123456__________________________", 6)
+        testcommon("%0#34.33o", big, "0o012345670123456701234567012345670")
         # Some small ints, in both Python int and flavors).
-        testformat("%d", 42, "42")
-        testformat("%d", -42, "-42")
-        testformat("%d", 42, "42")
-        testformat("%d", -42, "-42")
-        testformat("%d", 42.0, "42")
-        testformat("%#x", 1, "0x1")
-        testformat("%#x", 1, "0x1")
-        testformat("%#X", 1, "0X1")
-        testformat("%#X", 1, "0X1")
-        with self.assertWarns(DeprecationWarning):
-            testformat("%#x", 1.0, "0x1")
-        testformat("%#o", 1, "0o1")
-        testformat("%#o", 1, "0o1")
-        testformat("%#o", 0, "0o0")
-        testformat("%#o", 0, "0o0")
-        testformat("%o", 0, "0")
-        testformat("%o", 0, "0")
-        testformat("%d", 0, "0")
-        testformat("%d", 0, "0")
-        testformat("%#x", 0, "0x0")
-        testformat("%#x", 0, "0x0")
-        testformat("%#X", 0, "0X0")
-        testformat("%#X", 0, "0X0")
-        testformat("%x", 0x42, "42")
-        testformat("%x", -0x42, "-42")
-        testformat("%x", 0x42, "42")
-        testformat("%x", -0x42, "-42")
-        with self.assertWarns(DeprecationWarning):
-            testformat("%x", float(0x42), "42")
-        testformat("%o", 0o42, "42")
-        testformat("%o", -0o42, "-42")
-        testformat("%o", 0o42, "42")
-        testformat("%o", -0o42, "-42")
-        with self.assertWarns(DeprecationWarning):
-            testformat("%o", float(0o42), "42")
+        testcommon("%d", 42, "42")
+        testcommon("%d", -42, "-42")
+        testcommon("%d", 42, "42")
+        testcommon("%d", -42, "-42")
+        testcommon("%d", 42.0, "42")
+        testcommon("%#x", 1, "0x1")
+        testcommon("%#x", 1, "0x1")
+        testcommon("%#X", 1, "0X1")
+        testcommon("%#X", 1, "0X1")
+        testcommon("%#o", 1, "0o1")
+        testcommon("%#o", 1, "0o1")
+        testcommon("%#o", 0, "0o0")
+        testcommon("%#o", 0, "0o0")
+        testcommon("%o", 0, "0")
+        testcommon("%o", 0, "0")
+        testcommon("%d", 0, "0")
+        testcommon("%d", 0, "0")
+        testcommon("%#x", 0, "0x0")
+        testcommon("%#x", 0, "0x0")
+        testcommon("%#X", 0, "0X0")
+        testcommon("%#X", 0, "0X0")
+        testcommon("%x", 0x42, "42")
+        testcommon("%x", -0x42, "-42")
+        testcommon("%x", 0x42, "42")
+        testcommon("%x", -0x42, "-42")
+        testcommon("%o", 0o42, "42")
+        testcommon("%o", -0o42, "-42")
+        testcommon("%o", 0o42, "42")
+        testcommon("%o", -0o42, "-42")
+        # alternate float formatting
+        testcommon('%g', 1.1, '1.1')
+        testcommon('%#g', 1.1, '1.10000')
+
+    def test_str_format(self):
         testformat("%r", "\u0378", "'\\u0378'")  # non printable
         testformat("%a", "\u0378", "'\\u0378'")  # non printable
         testformat("%r", "\u0374", "'\u0374'")   # printable
         testformat("%a", "\u0374", "'\\u0374'")  # printable
 
-        # alternate float formatting
-        testformat('%g', 1.1, '1.1')
-        testformat('%#g', 1.1, '1.10000')
-
-        # Test exception for unknown format characters
+        # Test exception for unknown format characters, etc.
         if verbose:
             print('Testing exceptions')
         def test_exc(formatstr, args, exception, excmsg):
@@ -257,8 +275,83 @@ class FormatTest(unittest.TestCase):
         test_exc('%g', '1', TypeError, "a float is required")
         test_exc('no format', '1', TypeError,
                  "not all arguments converted during string formatting")
-        test_exc('no format', '1', TypeError,
-                 "not all arguments converted during string formatting")
+
+        if maxsize == 2**31-1:
+            # crashes 2.2.1 and earlier:
+            try:
+                "%*d"%(maxsize, -127)
+            except MemoryError:
+                pass
+            else:
+                raise TestFailed('"%*d"%(maxsize, -127) should fail')
+
+    def test_bytes_and_bytearray_format(self):
+        # %c will insert a single byte, either from an int in range(256), or
+        # from a bytes argument of length 1, not from a str.
+        testcommon(b"%c", 7, b"\x07")
+        testcommon(b"%c", b"Z", b"Z")
+        testcommon(b"%c", bytearray(b"Z"), b"Z")
+        # %b will insert a series of bytes, either from a type that supports
+        # the Py_buffer protocol, or something that has a __bytes__ method
+        class FakeBytes(object):
+            def __bytes__(self):
+                return b'123'
+        fb = FakeBytes()
+        testcommon(b"%b", b"abc", b"abc")
+        testcommon(b"%b", bytearray(b"def"), b"def")
+        testcommon(b"%b", fb, b"123")
+        # # %s is an alias for %b -- should only be used for Py2/3 code
+        testcommon(b"%s", b"abc", b"abc")
+        testcommon(b"%s", bytearray(b"def"), b"def")
+        testcommon(b"%s", fb, b"123")
+        # %a will give the equivalent of
+        # repr(some_obj).encode('ascii', 'backslashreplace')
+        testcommon(b"%a", 3.14, b"3.14")
+        testcommon(b"%a", b"ghi", b"b'ghi'")
+        testcommon(b"%a", "jkl", b"'jkl'")
+        testcommon(b"%a", "\u0544", b"'\\u0544'")
+
+        # Test exception for unknown format characters, etc.
+        if verbose:
+            print('Testing exceptions')
+        def test_exc(formatstr, args, exception, excmsg):
+            try:
+                testformat(formatstr, args)
+            except exception as exc:
+                if str(exc) == excmsg:
+                    if verbose:
+                        print("yes")
+                else:
+                    if verbose: print('no')
+                    print('Unexpected ', exception, ':', repr(str(exc)))
+            except:
+                if verbose: print('no')
+                print('Unexpected exception')
+                raise
+            else:
+                raise TestFailed('did not get expected exception: %s' % excmsg)
+        test_exc(b'%d', '1', TypeError,
+                "%d format: a number is required, not str")
+        test_exc(b'%d', b'1', TypeError,
+                "%d format: a number is required, not bytes")
+        test_exc(b'%g', '1', TypeError, "float argument required, not str")
+        test_exc(b'%g', b'1', TypeError, "float argument required, not bytes")
+        test_exc(b'no format', 7, TypeError,
+                 "not all arguments converted during bytes formatting")
+        test_exc(b'no format', b'1', TypeError,
+                 "not all arguments converted during bytes formatting")
+        test_exc(b'no format', bytearray(b'1'), TypeError,
+                 "not all arguments converted during bytes formatting")
+        test_exc(b"%c", 256, TypeError,
+                "%c requires an integer in range(256) or a single byte")
+        test_exc(b"%c", b"Za", TypeError,
+                "%c requires an integer in range(256) or a single byte")
+        test_exc(b"%c", "Yb", TypeError,
+                "%c requires an integer in range(256) or a single byte")
+        test_exc(b"%b", "Xc", TypeError,
+                "%b requires bytes, or an object that implements __bytes__, not 'str'")
+        test_exc(b"%s", "Wd", TypeError,
+                "%b requires bytes, or an object that implements __bytes__, not 'str'")
 
         if maxsize == 2**31-1:
             # crashes 2.2.1 and earlier:
diff --git a/Lib/test/test_fractions.py b/Lib/test/test_fractions.py
index 33365322b9..e86d5cee6e 100644
--- a/Lib/test/test_fractions.py
+++ b/Lib/test/test_fractions.py
@@ -330,7 +330,6 @@ class FractionTest(unittest.TestCase):
         self.assertTypedEquals(F(-2, 10), round(F(-15, 100), 1))
         self.assertTypedEquals(F(-2, 10), round(F(-25, 100), 1))
 
-
     def testArithmetic(self):
         self.assertEqual(F(1, 2), F(1, 10) + F(2, 5))
         self.assertEqual(F(-3, 10), F(1, 10) - F(2, 5))
@@ -402,6 +401,8 @@ class FractionTest(unittest.TestCase):
         self.assertTypedEquals(2.0 , 4 ** F(1, 2))
         self.assertTypedEquals(0.25, 2.0 ** F(-2, 1))
         self.assertTypedEquals(1.0 + 0j, (1.0 + 0j) ** F(1, 10))
+        self.assertRaises(ZeroDivisionError, operator.pow,
+                          F(0, 1), -2)
 
     def testMixingWithDecimal(self):
         # Decimal refuses mixed arithmetic (but not mixed comparisons)
diff --git a/Lib/test/test_ftplib.py b/Lib/test/test_ftplib.py
index d3be7d6d00..aef66da98a 100644
--- a/Lib/test/test_ftplib.py
+++ b/Lib/test/test_ftplib.py
@@ -73,7 +73,7 @@ class DummyDTPHandler(asynchat.async_chat):
         super(DummyDTPHandler, self).push(what.encode('ascii'))
 
     def handle_error(self):
-        raise
+        raise Exception
 
 
 class DummyFTPHandler(asynchat.async_chat):
@@ -118,7 +118,7 @@ class DummyFTPHandler(asynchat.async_chat):
             self.push('550 command "%s" not understood.' %cmd)
 
     def handle_error(self):
-        raise
+        raise Exception
 
     def push(self, data):
         asynchat.async_chat.push(self, data.encode('ascii') + b'\r\n')
@@ -134,7 +134,7 @@ class DummyFTPHandler(asynchat.async_chat):
     def cmd_pasv(self, arg):
         with socket.socket() as sock:
             sock.bind((self.socket.getsockname()[0], 0))
-            sock.listen(5)
+            sock.listen()
             sock.settimeout(TIMEOUT)
             ip, port = sock.getsockname()[:2]
             ip = ip.replace('.', ','); p1 = port / 256; p2 = port % 256
@@ -152,7 +152,7 @@ class DummyFTPHandler(asynchat.async_chat):
     def cmd_epsv(self, arg):
         with socket.socket(socket.AF_INET6) as sock:
             sock.bind((self.socket.getsockname()[0], 0))
-            sock.listen(5)
+            sock.listen()
             sock.settimeout(TIMEOUT)
             port = sock.getsockname()[1]
             self.push('229 entering extended passive mode (|||%d|)' %port)
@@ -296,7 +296,7 @@ class DummyFTPServer(asyncore.dispatcher, threading.Thread):
         return 0
 
     def handle_error(self):
-        raise
+        raise Exception
 
 
 if ssl is not None:
@@ -394,7 +394,7 @@ if ssl is not None:
                 raise
 
         def handle_error(self):
-            raise
+            raise Exception
 
         def close(self):
             if (isinstance(self.socket, ssl.SSLSocket) and
@@ -670,7 +670,7 @@ class TestFTPClass(TestCase):
         self.assertRaises(StopIteration, next, self.client.mlsd())
         set_data('')
         for x in self.client.mlsd():
-            self.fail("unexpected data %s" % data)
+            self.fail("unexpected data %s" % x)
 
     def test_makeport(self):
         with self.client.makeport():
@@ -979,7 +979,7 @@ class TestTimeouts(TestCase):
         #  1) when the connection is ready to be accepted.
         #  2) when it is safe for the caller to close the connection
         #  3) when we have closed the socket
-        self.sock.listen(5)
+        self.sock.listen()
         # (1) Signal the caller that we are ready to accept the connection.
         self.evt.set()
         try:
@@ -1049,19 +1049,8 @@ class TestTimeouts(TestCase):
         ftp.close()
 
 
-class TestNetrcDeprecation(TestCase):
-
-    def test_deprecation(self):
-        with support.temp_cwd(), support.EnvironmentVarGuard() as env:
-            env['HOME'] = os.getcwd()
-            open('.netrc', 'w').close()
-            with self.assertWarns(DeprecationWarning):
-                ftplib.Netrc()
-
-
-
 def test_main():
-    tests = [TestFTPClass, TestTimeouts, TestNetrcDeprecation,
+    tests = [TestFTPClass, TestTimeouts,
              TestIPv6Environment,
              TestTLS_FTPClassMixin, TestTLS_FTPClass]
 
diff --git a/Lib/test/test_functools.py b/Lib/test/test_functools.py
index 0375601c51..55b96b4b8f 100644
--- a/Lib/test/test_functools.py
+++ b/Lib/test/test_functools.py
@@ -882,6 +882,24 @@ class TestTotalOrdering(unittest.TestCase):
             with self.assertRaises(TypeError):
                 a <= b
 
+    def test_pickle(self):
+        for proto in range(4, pickle.HIGHEST_PROTOCOL + 1):
+            for name in '__lt__', '__gt__', '__le__', '__ge__':
+                with self.subTest(method=name, proto=proto):
+                    method = getattr(Orderable_LT, name)
+                    method_copy = pickle.loads(pickle.dumps(method, proto))
+                    self.assertIs(method_copy, method)
+
+@functools.total_ordering
+class Orderable_LT:
+    def __init__(self, value):
+        self.value = value
+    def __lt__(self, other):
+        return self.value < other.value
+    def __eq__(self, other):
+        return self.value == other.value
+
+
 class TestLRU(unittest.TestCase):
 
     def test_lru(self):
diff --git a/Lib/test/test_generators.py b/Lib/test/test_generators.py
index 7825a77339..9e610132cd 100644
--- a/Lib/test/test_generators.py
+++ b/Lib/test/test_generators.py
@@ -50,6 +50,45 @@ class FinalizationTest(unittest.TestCase):
         self.assertEqual(gc.garbage, old_garbage)
 
 
+class GeneratorTest(unittest.TestCase):
+
+    def test_name(self):
+        def func():
+            yield 1
+
+        # check generator names
+        gen = func()
+        self.assertEqual(gen.__name__, "func")
+        self.assertEqual(gen.__qualname__,
+                         "GeneratorTest.test_name.<locals>.func")
+
+        # modify generator names
+        gen.__name__ = "name"
+        gen.__qualname__ = "qualname"
+        self.assertEqual(gen.__name__, "name")
+        self.assertEqual(gen.__qualname__, "qualname")
+
+        # generator names must be a string and cannot be deleted
+        self.assertRaises(TypeError, setattr, gen, '__name__', 123)
+        self.assertRaises(TypeError, setattr, gen, '__qualname__', 123)
+        self.assertRaises(TypeError, delattr, gen, '__name__')
+        self.assertRaises(TypeError, delattr, gen, '__qualname__')
+
+        # modify names of the function creating the generator
+        func.__qualname__ = "func_qualname"
+        func.__name__ = "func_name"
+        gen = func()
+        self.assertEqual(gen.__name__, "func_name")
+        self.assertEqual(gen.__qualname__, "func_qualname")
+
+        # unnamed generator
+        gen = (x for x in range(10))
+        self.assertEqual(gen.__name__,
+                         "<genexpr>")
+        self.assertEqual(gen.__qualname__,
+                         "GeneratorTest.test_name.<locals>.<genexpr>")
+
+
 class ExceptionTest(unittest.TestCase):
     # Tests for the issue #23353: check that the currently handled exception
     # is correctly saved/restored in PyEval_EvalFrameEx().
diff --git a/Lib/test/test_genericpath.py b/Lib/test/test_genericpath.py
index e59ed4d21c..f2722bcc8a 100644
--- a/Lib/test/test_genericpath.py
+++ b/Lib/test/test_genericpath.py
@@ -434,6 +434,40 @@ class CommonTest(GenericTest):
             with support.temp_cwd(name):
                 self.test_abspath()
 
+    def test_join_errors(self):
+        # Check join() raises friendly TypeErrors.
+        with support.check_warnings(('', BytesWarning), quiet=True):
+            errmsg = "Can't mix strings and bytes in path components"
+            with self.assertRaisesRegex(TypeError, errmsg):
+                self.pathmodule.join(b'bytes', 'str')
+            with self.assertRaisesRegex(TypeError, errmsg):
+                self.pathmodule.join('str', b'bytes')
+            # regression, see #15377
+            errmsg = r'join\(\) argument must be str or bytes, not %r'
+            with self.assertRaisesRegex(TypeError, errmsg % 'int'):
+                self.pathmodule.join(42, 'str')
+            with self.assertRaisesRegex(TypeError, errmsg % 'int'):
+                self.pathmodule.join('str', 42)
+            with self.assertRaisesRegex(TypeError, errmsg % 'bytearray'):
+                self.pathmodule.join(bytearray(b'foo'), bytearray(b'bar'))
+
+    def test_relpath_errors(self):
+        # Check relpath() raises friendly TypeErrors.
+        with support.check_warnings(('', (BytesWarning, DeprecationWarning)),
+                                    quiet=True):
+            errmsg = "Can't mix strings and bytes in path components"
+            with self.assertRaisesRegex(TypeError, errmsg):
+                self.pathmodule.relpath(b'bytes', 'str')
+            with self.assertRaisesRegex(TypeError, errmsg):
+                self.pathmodule.relpath('str', b'bytes')
+            errmsg = r'relpath\(\) argument must be str or bytes, not %r'
+            with self.assertRaisesRegex(TypeError, errmsg % 'int'):
+                self.pathmodule.relpath(42, 'str')
+            with self.assertRaisesRegex(TypeError, errmsg % 'int'):
+                self.pathmodule.relpath('str', 42)
+            with self.assertRaisesRegex(TypeError, errmsg % 'bytearray'):
+                self.pathmodule.relpath(bytearray(b'foo'), bytearray(b'bar'))
+
 
 if __name__=="__main__":
     unittest.main()
diff --git a/Lib/test/test_getargs2.py b/Lib/test/test_getargs2.py
index 1853a2dbed..71472cd163 100644
--- a/Lib/test/test_getargs2.py
+++ b/Lib/test/test_getargs2.py
@@ -34,8 +34,8 @@ except ImportError:
 # > ** Changed from previous "range-and-a-half" to "none"; the
 # > range-and-a-half checking wasn't particularly useful.
 #
-# Plus a C API or two, e.g. PyInt_AsLongMask() ->
-# unsigned long and PyInt_AsLongLongMask() -> unsigned
+# Plus a C API or two, e.g. PyLong_AsUnsignedLongMask() ->
+# unsigned long and PyLong_AsUnsignedLongLongMask() -> unsigned
 # long long (if that exists).
 
 LARGE = 0x7FFFFFFF
@@ -482,7 +482,7 @@ class Bytes_TestCase(unittest.TestCase):
     def test_s(self):
         from _testcapi import getargs_s
         self.assertEqual(getargs_s('abc\xe9'), b'abc\xc3\xa9')
-        self.assertRaises(TypeError, getargs_s, 'nul:\0')
+        self.assertRaises(ValueError, getargs_s, 'nul:\0')
         self.assertRaises(TypeError, getargs_s, b'bytes')
         self.assertRaises(TypeError, getargs_s, bytearray(b'bytearray'))
         self.assertRaises(TypeError, getargs_s, memoryview(b'memoryview'))
@@ -509,7 +509,7 @@ class Bytes_TestCase(unittest.TestCase):
     def test_z(self):
         from _testcapi import getargs_z
         self.assertEqual(getargs_z('abc\xe9'), b'abc\xc3\xa9')
-        self.assertRaises(TypeError, getargs_z, 'nul:\0')
+        self.assertRaises(ValueError, getargs_z, 'nul:\0')
         self.assertRaises(TypeError, getargs_z, b'bytes')
         self.assertRaises(TypeError, getargs_z, bytearray(b'bytearray'))
         self.assertRaises(TypeError, getargs_z, memoryview(b'memoryview'))
@@ -537,7 +537,7 @@ class Bytes_TestCase(unittest.TestCase):
         from _testcapi import getargs_y
         self.assertRaises(TypeError, getargs_y, 'abc\xe9')
         self.assertEqual(getargs_y(b'bytes'), b'bytes')
-        self.assertRaises(TypeError, getargs_y, b'nul:\0')
+        self.assertRaises(ValueError, getargs_y, b'nul:\0')
         self.assertRaises(TypeError, getargs_y, bytearray(b'bytearray'))
         self.assertRaises(TypeError, getargs_y, memoryview(b'memoryview'))
         self.assertRaises(TypeError, getargs_y, None)
@@ -577,7 +577,7 @@ class Unicode_TestCase(unittest.TestCase):
     def test_u(self):
         from _testcapi import getargs_u
         self.assertEqual(getargs_u('abc\xe9'), 'abc\xe9')
-        self.assertRaises(TypeError, getargs_u, 'nul:\0')
+        self.assertRaises(ValueError, getargs_u, 'nul:\0')
         self.assertRaises(TypeError, getargs_u, b'bytes')
         self.assertRaises(TypeError, getargs_u, bytearray(b'bytearray'))
         self.assertRaises(TypeError, getargs_u, memoryview(b'memoryview'))
@@ -595,7 +595,7 @@ class Unicode_TestCase(unittest.TestCase):
     def test_Z(self):
         from _testcapi import getargs_Z
         self.assertEqual(getargs_Z('abc\xe9'), 'abc\xe9')
-        self.assertRaises(TypeError, getargs_Z, 'nul:\0')
+        self.assertRaises(ValueError, getargs_Z, 'nul:\0')
         self.assertRaises(TypeError, getargs_Z, b'bytes')
         self.assertRaises(TypeError, getargs_Z, bytearray(b'bytearray'))
         self.assertRaises(TypeError, getargs_Z, memoryview(b'memoryview'))
diff --git a/Lib/test/test_gettext.py b/Lib/test/test_gettext.py
index abb312f060..c7ceb3ffe7 100644
--- a/Lib/test/test_gettext.py
+++ b/Lib/test/test_gettext.py
@@ -33,6 +33,55 @@ IHNiZSBsYmhlIENsZ3ViYSBjZWJ0ZW56ZiBvbCBjZWJpdnF2YXQgbmEgdmFncmVzbnByIGdiIGd1
 ciBUQUgKdHJnZ3JrZyB6cmZmbnRyIHBuZ255YnQgeXZvZW5lbC4AYmFjb24Ad2luayB3aW5rAA==
 '''
 
+# This data contains an invalid major version number (5)
+# An unexpected major version number should be treated as an error when
+# parsing a .mo file
+
+GNU_MO_DATA_BAD_MAJOR_VERSION = b'''\
+3hIElQAABQAGAAAAHAAAAEwAAAALAAAAfAAAAAAAAACoAAAAFQAAAKkAAAAjAAAAvwAAAKEAAADj
+AAAABwAAAIUBAAALAAAAjQEAAEUBAACZAQAAFgAAAN8CAAAeAAAA9gIAAKEAAAAVAwAABQAAALcD
+AAAJAAAAvQMAAAEAAAADAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAEAAAABQAAAAYAAAACAAAAAFJh
+eW1vbmQgTHV4dXJ5IFlhY2gtdABUaGVyZSBpcyAlcyBmaWxlAFRoZXJlIGFyZSAlcyBmaWxlcwBU
+aGlzIG1vZHVsZSBwcm92aWRlcyBpbnRlcm5hdGlvbmFsaXphdGlvbiBhbmQgbG9jYWxpemF0aW9u
+CnN1cHBvcnQgZm9yIHlvdXIgUHl0aG9uIHByb2dyYW1zIGJ5IHByb3ZpZGluZyBhbiBpbnRlcmZh
+Y2UgdG8gdGhlIEdOVQpnZXR0ZXh0IG1lc3NhZ2UgY2F0YWxvZyBsaWJyYXJ5LgBtdWxsdXNrAG51
+ZGdlIG51ZGdlAFByb2plY3QtSWQtVmVyc2lvbjogMi4wClBPLVJldmlzaW9uLURhdGU6IDIwMDAt
+MDgtMjkgMTI6MTktMDQ6MDAKTGFzdC1UcmFuc2xhdG9yOiBKLiBEYXZpZCBJYsOhw7FleiA8ai1k
+YXZpZEBub29zLmZyPgpMYW5ndWFnZS1UZWFtOiBYWCA8cHl0aG9uLWRldkBweXRob24ub3JnPgpN
+SU1FLVZlcnNpb246IDEuMApDb250ZW50LVR5cGU6IHRleHQvcGxhaW47IGNoYXJzZXQ9aXNvLTg4
+NTktMQpDb250ZW50LVRyYW5zZmVyLUVuY29kaW5nOiBub25lCkdlbmVyYXRlZC1CeTogcHlnZXR0
+ZXh0LnB5IDEuMQpQbHVyYWwtRm9ybXM6IG5wbHVyYWxzPTI7IHBsdXJhbD1uIT0xOwoAVGhyb2F0
+d29iYmxlciBNYW5ncm92ZQBIYXkgJXMgZmljaGVybwBIYXkgJXMgZmljaGVyb3MAR3V2ZiB6YnFo
+eXIgY2ViaXZxcmYgdmFncmVhbmd2YmFueXZtbmd2YmEgbmFxIHlicG55dm1uZ3ZiYQpmaGNjYmVn
+IHNiZSBsYmhlIENsZ3ViYSBjZWJ0ZW56ZiBvbCBjZWJpdnF2YXQgbmEgdmFncmVzbnByIGdiIGd1
+ciBUQUgKdHJnZ3JrZyB6cmZmbnRyIHBuZ255YnQgeXZvZW5lbC4AYmFjb24Ad2luayB3aW5rAA==
+'''
+
+# This data contains an invalid minor version number (7)
+# An unexpected minor version number only indicates that some of the file's
+# contents may not be able to be read. It does not indicate an error.
+
+GNU_MO_DATA_BAD_MINOR_VERSION = b'''\
+3hIElQcAAAAGAAAAHAAAAEwAAAALAAAAfAAAAAAAAACoAAAAFQAAAKkAAAAjAAAAvwAAAKEAAADj
+AAAABwAAAIUBAAALAAAAjQEAAEUBAACZAQAAFgAAAN8CAAAeAAAA9gIAAKEAAAAVAwAABQAAALcD
+AAAJAAAAvQMAAAEAAAADAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAEAAAABQAAAAYAAAACAAAAAFJh
+eW1vbmQgTHV4dXJ5IFlhY2gtdABUaGVyZSBpcyAlcyBmaWxlAFRoZXJlIGFyZSAlcyBmaWxlcwBU
+aGlzIG1vZHVsZSBwcm92aWRlcyBpbnRlcm5hdGlvbmFsaXphdGlvbiBhbmQgbG9jYWxpemF0aW9u
+CnN1cHBvcnQgZm9yIHlvdXIgUHl0aG9uIHByb2dyYW1zIGJ5IHByb3ZpZGluZyBhbiBpbnRlcmZh
+Y2UgdG8gdGhlIEdOVQpnZXR0ZXh0IG1lc3NhZ2UgY2F0YWxvZyBsaWJyYXJ5LgBtdWxsdXNrAG51
+ZGdlIG51ZGdlAFByb2plY3QtSWQtVmVyc2lvbjogMi4wClBPLVJldmlzaW9uLURhdGU6IDIwMDAt
+MDgtMjkgMTI6MTktMDQ6MDAKTGFzdC1UcmFuc2xhdG9yOiBKLiBEYXZpZCBJYsOhw7FleiA8ai1k
+YXZpZEBub29zLmZyPgpMYW5ndWFnZS1UZWFtOiBYWCA8cHl0aG9uLWRldkBweXRob24ub3JnPgpN
+SU1FLVZlcnNpb246IDEuMApDb250ZW50LVR5cGU6IHRleHQvcGxhaW47IGNoYXJzZXQ9aXNvLTg4
+NTktMQpDb250ZW50LVRyYW5zZmVyLUVuY29kaW5nOiBub25lCkdlbmVyYXRlZC1CeTogcHlnZXR0
+ZXh0LnB5IDEuMQpQbHVyYWwtRm9ybXM6IG5wbHVyYWxzPTI7IHBsdXJhbD1uIT0xOwoAVGhyb2F0
+d29iYmxlciBNYW5ncm92ZQBIYXkgJXMgZmljaGVybwBIYXkgJXMgZmljaGVyb3MAR3V2ZiB6YnFo
+eXIgY2ViaXZxcmYgdmFncmVhbmd2YmFueXZtbmd2YmEgbmFxIHlicG55dm1uZ3ZiYQpmaGNjYmVn
+IHNiZSBsYmhlIENsZ3ViYSBjZWJ0ZW56ZiBvbCBjZWJpdnF2YXQgbmEgdmFncmVzbnByIGdiIGd1
+ciBUQUgKdHJnZ3JrZyB6cmZmbnRyIHBuZ255YnQgeXZvZW5lbC4AYmFjb24Ad2luayB3aW5rAA==
+'''
+
+
 UMO_DATA = b'''\
 3hIElQAAAAACAAAAHAAAACwAAAAFAAAAPAAAAAAAAABQAAAABAAAAFEAAAAPAQAAVgAAAAQAAABm
 AQAAAQAAAAIAAAAAAAAAAAAAAAAAAAAAYWLDngBQcm9qZWN0LUlkLVZlcnNpb246IDIuMApQTy1S
@@ -56,6 +105,8 @@ bGUKR2VuZXJhdGVkLUJ5OiBweWdldHRleHQucHkgMS4zCgA=
 
 LOCALEDIR = os.path.join('xx', 'LC_MESSAGES')
 MOFILE = os.path.join(LOCALEDIR, 'gettext.mo')
+MOFILE_BAD_MAJOR_VERSION = os.path.join(LOCALEDIR, 'gettext_bad_major_version.mo')
+MOFILE_BAD_MINOR_VERSION = os.path.join(LOCALEDIR, 'gettext_bad_minor_version.mo')
 UMOFILE = os.path.join(LOCALEDIR, 'ugettext.mo')
 MMOFILE = os.path.join(LOCALEDIR, 'metadata.mo')
 
@@ -66,6 +117,10 @@ class GettextBaseTest(unittest.TestCase):
             os.makedirs(LOCALEDIR)
         with open(MOFILE, 'wb') as fp:
             fp.write(base64.decodebytes(GNU_MO_DATA))
+        with open(MOFILE_BAD_MAJOR_VERSION, 'wb') as fp:
+            fp.write(base64.decodebytes(GNU_MO_DATA_BAD_MAJOR_VERSION))
+        with open(MOFILE_BAD_MINOR_VERSION, 'wb') as fp:
+            fp.write(base64.decodebytes(GNU_MO_DATA_BAD_MINOR_VERSION))
         with open(UMOFILE, 'wb') as fp:
             fp.write(base64.decodebytes(UMO_DATA))
         with open(MMOFILE, 'wb') as fp:
@@ -166,6 +221,21 @@ class GettextTestCase2(GettextBaseTest):
     def test_textdomain(self):
         self.assertEqual(gettext.textdomain(), 'gettext')
 
+    def test_bad_major_version(self):
+        with open(MOFILE_BAD_MAJOR_VERSION, 'rb') as fp:
+            with self.assertRaises(OSError) as cm:
+                gettext.GNUTranslations(fp)
+
+            exception = cm.exception
+            self.assertEqual(exception.errno, 0)
+            self.assertEqual(exception.strerror, "Bad version number 5")
+            self.assertEqual(exception.filename, MOFILE_BAD_MAJOR_VERSION)
+
+    def test_bad_minor_version(self):
+        with open(MOFILE_BAD_MINOR_VERSION, 'rb') as fp:
+            # Check that no error is thrown with a bad minor version number
+            gettext.GNUTranslations(fp)
+
     def test_some_translations(self):
         eq = self.assertEqual
         # test some translations
diff --git a/Lib/test/test_glob.py b/Lib/test/test_glob.py
index a5ab8d6c3e..21b0153306 100644
--- a/Lib/test/test_glob.py
+++ b/Lib/test/test_glob.py
@@ -4,8 +4,8 @@ import shutil
 import sys
 import unittest
 
-from test.support import (run_unittest, TESTFN, skip_unless_symlink,
-                          can_symlink, create_empty_file)
+from test.support import (TESTFN, skip_unless_symlink,
+                          can_symlink, create_empty_file, change_cwd)
 
 
 class GlobTests(unittest.TestCase):
@@ -13,6 +13,9 @@ class GlobTests(unittest.TestCase):
     def norm(self, *parts):
         return os.path.normpath(os.path.join(self.tempdir, *parts))
 
+    def joins(self, *tuples):
+        return [os.path.join(self.tempdir, *parts) for parts in tuples]
+
     def mktemp(self, *parts):
         filename = self.norm(*parts)
         base, file = os.path.split(filename)
@@ -38,17 +41,17 @@ class GlobTests(unittest.TestCase):
     def tearDown(self):
         shutil.rmtree(self.tempdir)
 
-    def glob(self, *parts):
+    def glob(self, *parts, **kwargs):
         if len(parts) == 1:
             pattern = parts[0]
         else:
             pattern = os.path.join(*parts)
         p = os.path.join(self.tempdir, pattern)
-        res = glob.glob(p)
-        self.assertEqual(list(glob.iglob(p)), res)
+        res = glob.glob(p, **kwargs)
+        self.assertEqual(list(glob.iglob(p, **kwargs)), res)
         bres = [os.fsencode(x) for x in res]
-        self.assertEqual(glob.glob(os.fsencode(p)), bres)
-        self.assertEqual(list(glob.iglob(os.fsencode(p))), bres)
+        self.assertEqual(glob.glob(os.fsencode(p), **kwargs), bres)
+        self.assertEqual(list(glob.iglob(os.fsencode(p), **kwargs)), bres)
         return res
 
     def assertSequencesEqual_noorder(self, l1, l2):
@@ -192,9 +195,118 @@ class GlobTests(unittest.TestCase):
         check('//?/c:/?', '//?/c:/[?]')
         check('//*/*/*', '//*/*/[*]')
 
-def test_main():
-    run_unittest(GlobTests)
+    def rglob(self, *parts, **kwargs):
+        return self.glob(*parts, recursive=True, **kwargs)
+
+    def test_recursive_glob(self):
+        eq = self.assertSequencesEqual_noorder
+        full = [('ZZZ',),
+                ('a',), ('a', 'D'),
+                ('a', 'bcd'),
+                ('a', 'bcd', 'EF'),
+                ('a', 'bcd', 'efg'),
+                ('a', 'bcd', 'efg', 'ha'),
+                ('aaa',), ('aaa', 'zzzF'),
+                ('aab',), ('aab', 'F'),
+               ]
+        if can_symlink():
+            full += [('sym1',), ('sym2',),
+                     ('sym3',),
+                     ('sym3', 'EF'),
+                     ('sym3', 'efg'),
+                     ('sym3', 'efg', 'ha'),
+                    ]
+        eq(self.rglob('**'), self.joins(('',), *full))
+        eq(self.rglob('.', '**'), self.joins(('.',''),
+            *(('.',) + i for i in full)))
+        dirs = [('a', ''), ('a', 'bcd', ''), ('a', 'bcd', 'efg', ''),
+                ('aaa', ''), ('aab', '')]
+        if can_symlink():
+            dirs += [('sym3', ''), ('sym3', 'efg', '')]
+        eq(self.rglob('**', ''), self.joins(('',), *dirs))
+
+        eq(self.rglob('a', '**'), self.joins(
+            ('a', ''), ('a', 'D'), ('a', 'bcd'), ('a', 'bcd', 'EF'),
+            ('a', 'bcd', 'efg'), ('a', 'bcd', 'efg', 'ha')))
+        eq(self.rglob('a**'), self.joins(('a',), ('aaa',), ('aab',)))
+        expect = [('a', 'bcd', 'EF')]
+        if can_symlink():
+            expect += [('sym3', 'EF')]
+        eq(self.rglob('**', 'EF'), self.joins(*expect))
+        expect = [('a', 'bcd', 'EF'), ('aaa', 'zzzF'), ('aab', 'F')]
+        if can_symlink():
+            expect += [('sym3', 'EF')]
+        eq(self.rglob('**', '*F'), self.joins(*expect))
+        eq(self.rglob('**', '*F', ''), [])
+        eq(self.rglob('**', 'bcd', '*'), self.joins(
+            ('a', 'bcd', 'EF'), ('a', 'bcd', 'efg')))
+        eq(self.rglob('a', '**', 'bcd'), self.joins(('a', 'bcd')))
+
+        predir = os.path.abspath(os.curdir)
+        try:
+            os.chdir(self.tempdir)
+            join = os.path.join
+            eq(glob.glob('**', recursive=True), [join(*i) for i in full])
+            eq(glob.glob(join('**', ''), recursive=True),
+                [join(*i) for i in dirs])
+            eq(glob.glob(join('**','zz*F'), recursive=True),
+                [join('aaa', 'zzzF')])
+            eq(glob.glob('**zz*F', recursive=True), [])
+            expect = [join('a', 'bcd', 'EF')]
+            if can_symlink():
+                expect += [join('sym3', 'EF')]
+            eq(glob.glob(join('**', 'EF'), recursive=True), expect)
+        finally:
+            os.chdir(predir)
+
+
+@skip_unless_symlink
+class SymlinkLoopGlobTests(unittest.TestCase):
+
+    def test_selflink(self):
+        tempdir = TESTFN + "_dir"
+        os.makedirs(tempdir)
+        self.addCleanup(shutil.rmtree, tempdir)
+        with change_cwd(tempdir):
+            os.makedirs('dir')
+            create_empty_file(os.path.join('dir', 'file'))
+            os.symlink(os.curdir, os.path.join('dir', 'link'))
+
+            results = glob.glob('**', recursive=True)
+            self.assertEqual(len(results), len(set(results)))
+            results = set(results)
+            depth = 0
+            while results:
+                path = os.path.join(*(['dir'] + ['link'] * depth))
+                self.assertIn(path, results)
+                results.remove(path)
+                if not results:
+                    break
+                path = os.path.join(path, 'file')
+                self.assertIn(path, results)
+                results.remove(path)
+                depth += 1
+
+            results = glob.glob(os.path.join('**', 'file'), recursive=True)
+            self.assertEqual(len(results), len(set(results)))
+            results = set(results)
+            depth = 0
+            while results:
+                path = os.path.join(*(['dir'] + ['link'] * depth + ['file']))
+                self.assertIn(path, results)
+                results.remove(path)
+                depth += 1
+
+            results = glob.glob(os.path.join('**', ''), recursive=True)
+            self.assertEqual(len(results), len(set(results)))
+            results = set(results)
+            depth = 0
+            while results:
+                path = os.path.join(*(['dir'] + ['link'] * depth + ['']))
+                self.assertIn(path, results)
+                results.remove(path)
+                depth += 1
 
 
 if __name__ == "__main__":
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_grammar.py b/Lib/test/test_grammar.py
index 70d85b1c33..7069fb94ea 100644
--- a/Lib/test/test_grammar.py
+++ b/Lib/test/test_grammar.py
@@ -1016,6 +1016,20 @@ class GrammarTests(unittest.TestCase):
         self.assertFalse((False is 2) is 3)
         self.assertFalse(False is 2 is 3)
 
+    def test_matrix_mul(self):
+        # This is not intended to be a comprehensive test, rather just to be few
+        # samples of the @ operator in test_grammar.py.
+        class M:
+            def __matmul__(self, o):
+                return 4
+            def __imatmul__(self, o):
+                self.other = o
+                return self
+        m = M()
+        self.assertEqual(m @ m, 4)
+        m @= 42
+        self.assertEqual(m.other, 42)
+
 
 def test_main():
     run_unittest(TokenTests, GrammarTests)
diff --git a/Lib/test/test_heapq.py b/Lib/test/test_heapq.py
index b5a2fd803a..0dcd8c5161 100644
--- a/Lib/test/test_heapq.py
+++ b/Lib/test/test_heapq.py
@@ -6,14 +6,15 @@ import unittest
 
 from test import support
 from unittest import TestCase, skipUnless
+from operator import itemgetter
 
 py_heapq = support.import_fresh_module('heapq', blocked=['_heapq'])
 c_heapq = support.import_fresh_module('heapq', fresh=['_heapq'])
 
 # _heapq.nlargest/nsmallest are saved in heapq._nlargest/_smallest when
 # _heapq is imported, so check them there
-func_names = ['heapify', 'heappop', 'heappush', 'heappushpop',
-              'heapreplace', '_nlargest', '_nsmallest']
+func_names = ['heapify', 'heappop', 'heappush', 'heappushpop', 'heapreplace',
+              '_heappop_max', '_heapreplace_max', '_heapify_max']
 
 class TestModules(TestCase):
     def test_py_functions(self):
@@ -152,11 +153,21 @@ class TestHeap:
 
     def test_merge(self):
         inputs = []
-        for i in range(random.randrange(5)):
-            row = sorted(random.randrange(1000) for j in range(random.randrange(10)))
+        for i in range(random.randrange(25)):
+            row = []
+            for j in range(random.randrange(100)):
+                tup = random.choice('ABC'), random.randrange(-500, 500)
+                row.append(tup)
             inputs.append(row)
-        self.assertEqual(sorted(chain(*inputs)), list(self.module.merge(*inputs)))
-        self.assertEqual(list(self.module.merge()), [])
+
+        for key in [None, itemgetter(0), itemgetter(1), itemgetter(1, 0)]:
+            for reverse in [False, True]:
+                seqs = []
+                for seq in inputs:
+                    seqs.append(sorted(seq, key=key, reverse=reverse))
+                self.assertEqual(sorted(chain(*inputs), key=key, reverse=reverse),
+                                 list(self.module.merge(*seqs, key=key, reverse=reverse)))
+                self.assertEqual(list(self.module.merge()), [])
 
     def test_merge_does_not_suppress_index_error(self):
         # Issue 19018: Heapq.merge suppresses IndexError from user generator
diff --git a/Lib/test/test_htmlparser.py b/Lib/test/test_htmlparser.py
index 2d771a2a97..de8f3e80d4 100644
--- a/Lib/test/test_htmlparser.py
+++ b/Lib/test/test_htmlparser.py
@@ -85,7 +85,7 @@ class EventCollectorCharrefs(EventCollector):
 class TestCaseBase(unittest.TestCase):
 
     def get_collector(self):
-        raise NotImplementedError
+        return EventCollector(convert_charrefs=False)
 
     def _run_check(self, source, expected_events, collector=None):
         if collector is None:
@@ -105,21 +105,8 @@ class TestCaseBase(unittest.TestCase):
         self._run_check(source, events,
                         EventCollectorExtra(convert_charrefs=False))
 
-    def _parse_error(self, source):
-        def parse(source=source):
-            parser = self.get_collector()
-            parser.feed(source)
-            parser.close()
-        with self.assertRaises(html.parser.HTMLParseError):
-            with self.assertWarns(DeprecationWarning):
-                parse()
-
 
-class HTMLParserStrictTestCase(TestCaseBase):
-
-    def get_collector(self):
-        with support.check_warnings(("", DeprecationWarning), quite=False):
-            return EventCollector(strict=True, convert_charrefs=False)
+class HTMLParserTestCase(TestCaseBase):
 
     def test_processing_instruction_only(self):
         self._run_check("<?processing instruction>", [
@@ -201,9 +188,6 @@ text
             ("data", "this < text > contains < bare>pointy< brackets"),
             ])
 
-    def test_illegal_declarations(self):
-        self._parse_error('<!spacer type="block" height="25">')
-
     def test_starttag_end_boundary(self):
         self._run_check("""<a b='<'>""", [("starttag", "a", [("b", "<")])])
         self._run_check("""<a b='>'>""", [("starttag", "a", [("b", ">")])])
@@ -238,25 +222,6 @@ text
         self._run_check(["<!--abc--", ">"], output)
         self._run_check(["<!--abc-->", ""], output)
 
-    def test_starttag_junk_chars(self):
-        self._parse_error("</>")
-        self._parse_error("</$>")
-        self._parse_error("</")
-        self._parse_error("</a")
-        self._parse_error("<a<a>")
-        self._parse_error("</a<a>")
-        self._parse_error("<!")
-        self._parse_error("<a")
-        self._parse_error("<a foo='bar'")
-        self._parse_error("<a foo='bar")
-        self._parse_error("<a foo='>'")
-        self._parse_error("<a foo='>")
-        self._parse_error("<a$>")
-        self._parse_error("<a$b>")
-        self._parse_error("<a$b/>")
-        self._parse_error("<a$b  >")
-        self._parse_error("<a$b  />")
-
     def test_valid_doctypes(self):
         # from http://www.w3.org/QA/2002/04/valid-dtd-list.html
         dtds = ['HTML',  # HTML5 doctype
@@ -281,9 +246,6 @@ text
             self._run_check("<!DOCTYPE %s>" % dtd,
                             [('decl', 'DOCTYPE ' + dtd)])
 
-    def test_declaration_junk_chars(self):
-        self._parse_error("<!DOCTYPE foo $ >")
-
     def test_startendtag(self):
         self._run_check("<p/>", [
             ("startendtag", "p", []),
@@ -384,7 +346,8 @@ text
         self._run_check(html, expected)
 
     def test_convert_charrefs(self):
-        collector = lambda: EventCollectorCharrefs(convert_charrefs=True)
+        # default value for convert_charrefs is now True
+        collector = lambda: EventCollectorCharrefs()
         self.assertTrue(collector().convert_charrefs)
         charrefs = ['&quot;', '&#34;', '&#x22;', '&quot', '&#34', '&#x22']
         # check charrefs in the middle of the text/attributes
@@ -421,23 +384,8 @@ text
         self._run_check('no charrefs here', [('data', 'no charrefs here')],
                         collector=collector())
 
-
-class HTMLParserTolerantTestCase(HTMLParserStrictTestCase):
-
-    def get_collector(self):
-        return EventCollector(convert_charrefs=False)
-
-    def test_deprecation_warnings(self):
-        with self.assertWarns(DeprecationWarning):
-            EventCollector()  # convert_charrefs not passed explicitly
-        with self.assertWarns(DeprecationWarning):
-            EventCollector(strict=True)
-        with self.assertWarns(DeprecationWarning):
-            EventCollector(strict=False)
-        with self.assertRaises(html.parser.HTMLParseError):
-            with self.assertWarns(DeprecationWarning):
-                EventCollector().error('test')
-
+    # the remaining tests were for the "tolerant" parser (which is now
+    # the default), and check various kind of broken markup
     def test_tolerant_parsing(self):
         self._run_check('<html <html>te>>xt&a<<bc</a></html>\n'
                         '<img src="URL><//img></html</html>', [
@@ -686,11 +634,7 @@ class HTMLParserTolerantTestCase(HTMLParserStrictTestCase):
         self._run_check(html, expected)
 
 
-class AttributesStrictTestCase(TestCaseBase):
-
-    def get_collector(self):
-        with support.check_warnings(("", DeprecationWarning), quite=False):
-            return EventCollector(strict=True, convert_charrefs=False)
+class AttributesTestCase(TestCaseBase):
 
     def test_attr_syntax(self):
         output = [
@@ -747,12 +691,6 @@ class AttributesStrictTestCase(TestCaseBase):
             [("starttag", "html", [("foo", "\u20AC&aa&unsupported;")])])
 
 
-
-class AttributesTolerantTestCase(AttributesStrictTestCase):
-
-    def get_collector(self):
-        return EventCollector(convert_charrefs=False)
-
     def test_attr_funky_names2(self):
         self._run_check(
             "<a $><b $=%><c \=/>",
diff --git a/Lib/test/test_http_cookies.py b/Lib/test/test_http_cookies.py
index e9842526f0..ee30f17480 100644
--- a/Lib/test/test_http_cookies.py
+++ b/Lib/test/test_http_cookies.py
@@ -141,13 +141,6 @@ class CookieTests(unittest.TestCase):
         self.assertEqual(C['eggs']['httponly'], 'foo')
         self.assertEqual(C['eggs']['secure'], 'bar')
 
-    def test_bad_attrs(self):
-        # issue 16611: make sure we don't break backward compatibility.
-        C = cookies.SimpleCookie()
-        C.load('cookie=with; invalid; version; second=cookie;')
-        self.assertEqual(C.output(),
-            'Set-Cookie: cookie=with\r\nSet-Cookie: second=cookie')
-
     def test_extra_spaces(self):
         C = cookies.SimpleCookie()
         C.load('eggs  =  scrambled  ;  secure  ;  path  =  bar   ; foo=foo   ')
@@ -182,7 +175,10 @@ class CookieTests(unittest.TestCase):
     def test_invalid_cookies(self):
         # Accepting these could be a security issue
         C = cookies.SimpleCookie()
-        for s in (']foo=x', '[foo=x', 'blah]foo=x', 'blah[foo=x'):
+        for s in (']foo=x', '[foo=x', 'blah]foo=x', 'blah[foo=x',
+                  'Set-Cookie: foo=bar', 'Set-Cookie: foo',
+                  'foo=bar; baz', 'baz; foo=bar',
+                  'secure;foo=bar', 'Version=1;foo=bar'):
             C.load(s)
             self.assertEqual(dict(C), {})
             self.assertEqual(C.output(), '')
diff --git a/Lib/test/test_httplib.py b/Lib/test/test_httplib.py
index 3fc34665da..40ef250e9f 100644
--- a/Lib/test/test_httplib.py
+++ b/Lib/test/test_httplib.py
@@ -18,6 +18,26 @@ CERT_fakehostname = os.path.join(here, 'keycert2.pem')
 # Self-signed cert file for self-signed.pythontest.net
 CERT_selfsigned_pythontestdotnet = os.path.join(here, 'selfsigned_pythontestdotnet.pem')
 
+# constants for testing chunked encoding
+chunked_start = (
+    'HTTP/1.1 200 OK\r\n'
+    'Transfer-Encoding: chunked\r\n\r\n'
+    'a\r\n'
+    'hello worl\r\n'
+    '3\r\n'
+    'd! \r\n'
+    '8\r\n'
+    'and now \r\n'
+    '22\r\n'
+    'for something completely different\r\n'
+)
+chunked_expected = b'hello world! and now for something completely different'
+chunk_extension = ";foo=bar"
+last_chunk = "0\r\n"
+last_chunk_extended = "0" + chunk_extension + "\r\n"
+trailers = "X-Dummy: foo\r\nX-Dumm2: bar\r\n"
+chunked_end = "\r\n"
+
 HOST = support.HOST
 
 class FakeSocket:
@@ -50,6 +70,9 @@ class FakeSocket:
     def close(self):
         pass
 
+    def setsockopt(self, level, optname, value):
+        pass
+
 class EPipeSocket(FakeSocket):
 
     def __init__(self, text, pipe_trigger):
@@ -452,20 +475,8 @@ class BasicTest(TestCase):
             conn.request('POST', 'test', conn)
 
     def test_chunked(self):
-        chunked_start = (
-            'HTTP/1.1 200 OK\r\n'
-            'Transfer-Encoding: chunked\r\n\r\n'
-            'a\r\n'
-            'hello worl\r\n'
-            '3\r\n'
-            'd! \r\n'
-            '8\r\n'
-            'and now \r\n'
-            '22\r\n'
-            'for something completely different\r\n'
-        )
-        expected = b'hello world! and now for something completely different'
-        sock = FakeSocket(chunked_start + '0\r\n')
+        expected = chunked_expected
+        sock = FakeSocket(chunked_start + last_chunk + chunked_end)
         resp = client.HTTPResponse(sock, method="GET")
         resp.begin()
         self.assertEqual(resp.read(), expected)
@@ -473,7 +484,7 @@ class BasicTest(TestCase):
 
         # Various read sizes
         for n in range(1, 12):
-            sock = FakeSocket(chunked_start + '0\r\n')
+            sock = FakeSocket(chunked_start + last_chunk + chunked_end)
             resp = client.HTTPResponse(sock, method="GET")
             resp.begin()
             self.assertEqual(resp.read(n) + resp.read(n) + resp.read(), expected)
@@ -496,23 +507,12 @@ class BasicTest(TestCase):
                 resp.close()
 
     def test_readinto_chunked(self):
-        chunked_start = (
-            'HTTP/1.1 200 OK\r\n'
-            'Transfer-Encoding: chunked\r\n\r\n'
-            'a\r\n'
-            'hello worl\r\n'
-            '3\r\n'
-            'd! \r\n'
-            '8\r\n'
-            'and now \r\n'
-            '22\r\n'
-            'for something completely different\r\n'
-        )
-        expected = b'hello world! and now for something completely different'
+
+        expected = chunked_expected
         nexpected = len(expected)
         b = bytearray(128)
 
-        sock = FakeSocket(chunked_start + '0\r\n')
+        sock = FakeSocket(chunked_start + last_chunk + chunked_end)
         resp = client.HTTPResponse(sock, method="GET")
         resp.begin()
         n = resp.readinto(b)
@@ -522,7 +522,7 @@ class BasicTest(TestCase):
 
         # Various read sizes
         for n in range(1, 12):
-            sock = FakeSocket(chunked_start + '0\r\n')
+            sock = FakeSocket(chunked_start + last_chunk + chunked_end)
             resp = client.HTTPResponse(sock, method="GET")
             resp.begin()
             m = memoryview(b)
@@ -558,7 +558,7 @@ class BasicTest(TestCase):
             '1\r\n'
             'd\r\n'
         )
-        sock = FakeSocket(chunked_start + '0\r\n')
+        sock = FakeSocket(chunked_start + last_chunk + chunked_end)
         resp = client.HTTPResponse(sock, method="HEAD")
         resp.begin()
         self.assertEqual(resp.read(), b'')
@@ -578,7 +578,7 @@ class BasicTest(TestCase):
             '1\r\n'
             'd\r\n'
         )
-        sock = FakeSocket(chunked_start + '0\r\n')
+        sock = FakeSocket(chunked_start + last_chunk + chunked_end)
         resp = client.HTTPResponse(sock, method="HEAD")
         resp.begin()
         b = bytearray(5)
@@ -653,6 +653,7 @@ class BasicTest(TestCase):
             + '0' * 65536 + 'a\r\n'
             'hello world\r\n'
             '0\r\n'
+            '\r\n'
         )
         resp = client.HTTPResponse(FakeSocket(body))
         resp.begin()
@@ -670,28 +671,6 @@ class BasicTest(TestCase):
         resp.close()
         self.assertTrue(resp.closed)
 
-    def test_delayed_ack_opt(self):
-        # Test that Nagle/delayed_ack optimistaion works correctly.
-
-        # For small payloads, it should coalesce the body with
-        # headers, resulting in a single sendall() call
-        conn = client.HTTPConnection('example.com')
-        sock = FakeSocket(None)
-        conn.sock = sock
-        body = b'x' * (conn.mss - 1)
-        conn.request('POST', '/', body)
-        self.assertEqual(sock.sendall_calls, 1)
-
-        # For large payloads, it should send the headers and
-        # then the body, resulting in more than one sendall()
-        # call
-        conn = client.HTTPConnection('example.com')
-        sock = FakeSocket(None)
-        conn.sock = sock
-        body = b'x' * conn.mss
-        conn.request('POST', '/', body)
-        self.assertGreater(sock.sendall_calls, 1)
-
     def test_error_leak(self):
         # Test that the socket is not leaked if getresponse() fails
         conn = client.HTTPConnection('example.com')
@@ -708,6 +687,239 @@ class BasicTest(TestCase):
         self.assertTrue(response.closed)
         self.assertTrue(conn.sock.file_closed)
 
+    def test_chunked_extension(self):
+        extra = '3;foo=bar\r\n' + 'abc\r\n'
+        expected = chunked_expected + b'abc'
+
+        sock = FakeSocket(chunked_start + extra + last_chunk_extended + chunked_end)
+        resp = client.HTTPResponse(sock, method="GET")
+        resp.begin()
+        self.assertEqual(resp.read(), expected)
+        resp.close()
+
+    def test_chunked_missing_end(self):
+        """some servers may serve up a short chunked encoding stream"""
+        expected = chunked_expected
+        sock = FakeSocket(chunked_start + last_chunk)  #no terminating crlf
+        resp = client.HTTPResponse(sock, method="GET")
+        resp.begin()
+        self.assertEqual(resp.read(), expected)
+        resp.close()
+
+    def test_chunked_trailers(self):
+        """See that trailers are read and ignored"""
+        expected = chunked_expected
+        sock = FakeSocket(chunked_start + last_chunk + trailers + chunked_end)
+        resp = client.HTTPResponse(sock, method="GET")
+        resp.begin()
+        self.assertEqual(resp.read(), expected)
+        # we should have reached the end of the file
+        self.assertEqual(sock.file.read(100), b"") #we read to the end
+        resp.close()
+
+    def test_chunked_sync(self):
+        """Check that we don't read past the end of the chunked-encoding stream"""
+        expected = chunked_expected
+        extradata = "extradata"
+        sock = FakeSocket(chunked_start + last_chunk + trailers + chunked_end + extradata)
+        resp = client.HTTPResponse(sock, method="GET")
+        resp.begin()
+        self.assertEqual(resp.read(), expected)
+        # the file should now have our extradata ready to be read
+        self.assertEqual(sock.file.read(100), extradata.encode("ascii")) #we read to the end
+        resp.close()
+
+    def test_content_length_sync(self):
+        """Check that we don't read past the end of the Content-Length stream"""
+        extradata = "extradata"
+        expected = b"Hello123\r\n"
+        sock = FakeSocket('HTTP/1.1 200 OK\r\nContent-Length: 10\r\n\r\nHello123\r\n' + extradata)
+        resp = client.HTTPResponse(sock, method="GET")
+        resp.begin()
+        self.assertEqual(resp.read(), expected)
+        # the file should now have our extradata ready to be read
+        self.assertEqual(sock.file.read(100), extradata.encode("ascii")) #we read to the end
+        resp.close()
+
+class ExtendedReadTest(TestCase):
+    """
+    Test peek(), read1(), readline()
+    """
+    lines = (
+        'HTTP/1.1 200 OK\r\n'
+        '\r\n'
+        'hello world!\n'
+        'and now \n'
+        'for something completely different\n'
+        'foo'
+        )
+    lines_expected = lines[lines.find('hello'):].encode("ascii")
+    lines_chunked = (
+        'HTTP/1.1 200 OK\r\n'
+        'Transfer-Encoding: chunked\r\n\r\n'
+        'a\r\n'
+        'hello worl\r\n'
+        '3\r\n'
+        'd!\n\r\n'
+        '9\r\n'
+        'and now \n\r\n'
+        '23\r\n'
+        'for something completely different\n\r\n'
+        '3\r\n'
+        'foo\r\n'
+        '0\r\n' # terminating chunk
+        '\r\n'  # end of trailers
+    )
+
+    def setUp(self):
+        sock = FakeSocket(self.lines)
+        resp = client.HTTPResponse(sock, method="GET")
+        resp.begin()
+        resp.fp = io.BufferedReader(resp.fp)
+        self.resp = resp
+
+
+
+    def test_peek(self):
+        resp = self.resp
+        # patch up the buffered peek so that it returns not too much stuff
+        oldpeek = resp.fp.peek
+        def mypeek(n=-1):
+            p = oldpeek(n)
+            if n >= 0:
+                return p[:n]
+            return p[:10]
+        resp.fp.peek = mypeek
+
+        all = []
+        while True:
+            # try a short peek
+            p = resp.peek(3)
+            if p:
+                self.assertGreater(len(p), 0)
+                # then unbounded peek
+                p2 = resp.peek()
+                self.assertGreaterEqual(len(p2), len(p))
+                self.assertTrue(p2.startswith(p))
+                next = resp.read(len(p2))
+                self.assertEqual(next, p2)
+            else:
+                next = resp.read()
+                self.assertFalse(next)
+            all.append(next)
+            if not next:
+                break
+        self.assertEqual(b"".join(all), self.lines_expected)
+
+    def test_readline(self):
+        resp = self.resp
+        self._verify_readline(self.resp.readline, self.lines_expected)
+
+    def _verify_readline(self, readline, expected):
+        all = []
+        while True:
+            # short readlines
+            line = readline(5)
+            if line and line != b"foo":
+                if len(line) < 5:
+                    self.assertTrue(line.endswith(b"\n"))
+            all.append(line)
+            if not line:
+                break
+        self.assertEqual(b"".join(all), expected)
+
+    def test_read1(self):
+        resp = self.resp
+        def r():
+            res = resp.read1(4)
+            self.assertLessEqual(len(res), 4)
+            return res
+        readliner = Readliner(r)
+        self._verify_readline(readliner.readline, self.lines_expected)
+
+    def test_read1_unbounded(self):
+        resp = self.resp
+        all = []
+        while True:
+            data = resp.read1()
+            if not data:
+                break
+            all.append(data)
+        self.assertEqual(b"".join(all), self.lines_expected)
+
+    def test_read1_bounded(self):
+        resp = self.resp
+        all = []
+        while True:
+            data = resp.read1(10)
+            if not data:
+                break
+            self.assertLessEqual(len(data), 10)
+            all.append(data)
+        self.assertEqual(b"".join(all), self.lines_expected)
+
+    def test_read1_0(self):
+        self.assertEqual(self.resp.read1(0), b"")
+
+    def test_peek_0(self):
+        p = self.resp.peek(0)
+        self.assertLessEqual(0, len(p))
+
+class ExtendedReadTestChunked(ExtendedReadTest):
+    """
+    Test peek(), read1(), readline() in chunked mode
+    """
+    lines = (
+        'HTTP/1.1 200 OK\r\n'
+        'Transfer-Encoding: chunked\r\n\r\n'
+        'a\r\n'
+        'hello worl\r\n'
+        '3\r\n'
+        'd!\n\r\n'
+        '9\r\n'
+        'and now \n\r\n'
+        '23\r\n'
+        'for something completely different\n\r\n'
+        '3\r\n'
+        'foo\r\n'
+        '0\r\n' # terminating chunk
+        '\r\n'  # end of trailers
+    )
+
+
+class Readliner:
+    """
+    a simple readline class that uses an arbitrary read function and buffering
+    """
+    def __init__(self, readfunc):
+        self.readfunc = readfunc
+        self.remainder = b""
+
+    def readline(self, limit):
+        data = []
+        datalen = 0
+        read = self.remainder
+        try:
+            while True:
+                idx = read.find(b'\n')
+                if idx != -1:
+                    break
+                if datalen + len(read) >= limit:
+                    idx = limit - datalen - 1
+                # read more data
+                data.append(read)
+                read = self.readfunc()
+                if not read:
+                    idx = 0 #eof condition
+                    break
+            idx += 1
+            data.append(read[:idx])
+            self.remainder = read[idx:]
+            return b"".join(data)
+        except:
+            self.remainder = b"".join(data)
+            raise
+
 class OfflineTest(TestCase):
     def test_responses(self):
         self.assertEqual(client.responses[client.NOT_FOUND], "Not Found")
@@ -718,7 +930,7 @@ class SourceAddressTest(TestCase):
         self.serv = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
         self.port = support.bind_port(self.serv)
         self.source_port = support.find_unused_port()
-        self.serv.listen(5)
+        self.serv.listen()
         self.conn = None
 
     def tearDown(self):
@@ -750,7 +962,7 @@ class TimeoutTest(TestCase):
     def setUp(self):
         self.serv = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
         TimeoutTest.PORT = support.bind_port(self.serv)
-        self.serv.listen(5)
+        self.serv.listen()
 
     def tearDown(self):
         self.serv.close()
@@ -1057,17 +1269,18 @@ class TunnelTests(TestCase):
             'HTTP/1.1 200 OK\r\n' # Reply to HEAD
             'Content-Length: 42\r\n\r\n'
         )
-
-        def create_connection(address, timeout=None, source_address=None):
-            return FakeSocket(response_text, host=address[0], port=address[1])
-
         self.host = 'proxy.com'
         self.conn = client.HTTPConnection(self.host)
-        self.conn._create_connection = create_connection
+        self.conn._create_connection = self._create_connection(response_text)
 
     def tearDown(self):
         self.conn.close()
 
+    def _create_connection(self, response_text):
+        def create_connection(address, timeout=None, source_address=None):
+            return FakeSocket(response_text, host=address[0], port=address[1])
+        return create_connection
+
     def test_set_tunnel_host_port_headers(self):
         tunnel_host = 'destination.com'
         tunnel_port = 8888
@@ -1108,13 +1321,26 @@ class TunnelTests(TestCase):
         self.assertIn(b'CONNECT destination.com', self.conn.sock.data)
         self.assertIn(b'Host: destination.com', self.conn.sock.data)
 
+    def test_tunnel_debuglog(self):
+        expected_header = 'X-Dummy: 1'
+        response_text = 'HTTP/1.0 200 OK\r\n{}\r\n\r\n'.format(expected_header)
+
+        self.conn.set_debuglevel(1)
+        self.conn._create_connection = self._create_connection(response_text)
+        self.conn.set_tunnel('destination.com')
+
+        with support.captured_stdout() as output:
+            self.conn.request('PUT', '/', '')
+        lines = output.getvalue().splitlines()
+        self.assertIn('header: {}'.format(expected_header), lines)
 
 
 @support.reap_threads
 def test_main(verbose=None):
     support.run_unittest(HeaderTests, OfflineTest, BasicTest, TimeoutTest,
                          HTTPSTest, RequestBodyTest, SourceAddressTest,
-                         HTTPResponseTest, TunnelTests)
+                         HTTPResponseTest, ExtendedReadTest,
+                         ExtendedReadTestChunked, TunnelTests)
 
 if __name__ == '__main__':
     test_main()
diff --git a/Lib/test/test_imaplib.py b/Lib/test/test_imaplib.py
index b34e652347..5485a2a7b7 100644
--- a/Lib/test/test_imaplib.py
+++ b/Lib/test/test_imaplib.py
@@ -11,7 +11,8 @@ import socketserver
 import time
 import calendar
 
-from test.support import reap_threads, verbose, transient_internet, run_with_tz, run_with_locale
+from test.support import (reap_threads, verbose, transient_internet,
+                          run_with_tz, run_with_locale)
 import unittest
 from datetime import datetime, timezone, timedelta
 try:
@@ -19,8 +20,8 @@ try:
 except ImportError:
     ssl = None
 
-CERTFILE = None
-CAFILE = None
+CERTFILE = os.path.join(os.path.dirname(__file__) or os.curdir, "keycert3.pem")
+CAFILE = os.path.join(os.path.dirname(__file__) or os.curdir, "pycacert.pem")
 
 
 class TestImaplib(unittest.TestCase):
@@ -41,17 +42,15 @@ class TestImaplib(unittest.TestCase):
     def test_Internaldate2tuple_issue10941(self):
         self.assertNotEqual(imaplib.Internaldate2tuple(
             b'25 (INTERNALDATE "02-Apr-2000 02:30:00 +0000")'),
-                            imaplib.Internaldate2tuple(
-            b'25 (INTERNALDATE "02-Apr-2000 03:30:00 +0000")'))
-
-
+            imaplib.Internaldate2tuple(
+                b'25 (INTERNALDATE "02-Apr-2000 03:30:00 +0000")'))
 
     def timevalues(self):
         return [2000000000, 2000000000.0, time.localtime(2000000000),
                 (2033, 5, 18, 5, 33, 20, -1, -1, -1),
                 (2033, 5, 18, 5, 33, 20, -1, -1, 1),
                 datetime.fromtimestamp(2000000000,
-                                       timezone(timedelta(0, 2*60*60))),
+                                       timezone(timedelta(0, 2 * 60 * 60))),
                 '"18-May-2033 05:33:20 +0200"']
 
     @run_with_locale('LC_ALL', 'de_DE', 'fr_FR')
@@ -72,7 +71,6 @@ class TestImaplib(unittest.TestCase):
 
 
 if ssl:
-
     class SecureTCPServer(socketserver.TCPServer):
 
         def get_request(self):
@@ -93,13 +91,17 @@ else:
 
 
 class SimpleIMAPHandler(socketserver.StreamRequestHandler):
-
     timeout = 1
     continuation = None
     capabilities = ''
 
+    def setup(self):
+        super().setup()
+        self.server.logged = None
+
     def _send(self, message):
-        if verbose: print("SENT: %r" % message.strip())
+        if verbose:
+            print("SENT: %r" % message.strip())
         self.wfile.write(message)
 
     def _send_line(self, message):
@@ -132,7 +134,8 @@ class SimpleIMAPHandler(socketserver.StreamRequestHandler):
                 if line.endswith(b'\r\n'):
                     break
 
-            if verbose: print('GOT: %r' % line.strip())
+            if verbose:
+                print('GOT: %r' % line.strip())
             if self.continuation:
                 try:
                     self.continuation.send(line)
@@ -144,8 +147,8 @@ class SimpleIMAPHandler(socketserver.StreamRequestHandler):
             cmd = splitline[1]
             args = splitline[2:]
 
-            if hasattr(self, 'cmd_'+cmd):
-                continuation = getattr(self, 'cmd_'+cmd)(tag, args)
+            if hasattr(self, 'cmd_' + cmd):
+                continuation = getattr(self, 'cmd_' + cmd)(tag, args)
                 if continuation:
                     self.continuation = continuation
                     next(continuation)
@@ -153,16 +156,25 @@ class SimpleIMAPHandler(socketserver.StreamRequestHandler):
                 self._send_tagged(tag, 'BAD', cmd + ' unknown')
 
     def cmd_CAPABILITY(self, tag, args):
-        caps = 'IMAP4rev1 ' + self.capabilities if self.capabilities else 'IMAP4rev1'
+        caps = ('IMAP4rev1 ' + self.capabilities
+                if self.capabilities
+                else 'IMAP4rev1')
         self._send_textline('* CAPABILITY ' + caps)
         self._send_tagged(tag, 'OK', 'CAPABILITY completed')
 
     def cmd_LOGOUT(self, tag, args):
+        self.server.logged = None
         self._send_textline('* BYE IMAP4ref1 Server logging out')
         self._send_tagged(tag, 'OK', 'LOGOUT completed')
 
+    def cmd_LOGIN(self, tag, args):
+        self.server.logged = args[0]
+        self._send_tagged(tag, 'OK', 'LOGIN completed')
 
-class BaseThreadedNetworkedTests(unittest.TestCase):
+
+class ThreadedNetworkedTests(unittest.TestCase):
+    server_class = socketserver.TCPServer
+    imap_class = imaplib.IMAP4
 
     def make_server(self, addr, hdlr):
 
@@ -172,7 +184,8 @@ class BaseThreadedNetworkedTests(unittest.TestCase):
                 self.server_close()
                 raise
 
-        if verbose: print("creating server")
+        if verbose:
+            print("creating server")
         server = MyServer(addr, hdlr)
         self.assertEqual(server.server_address, server.socket.getsockname())
 
@@ -188,18 +201,21 @@ class BaseThreadedNetworkedTests(unittest.TestCase):
             # Short poll interval to make the test finish quickly.
             # Time between requests is short enough that we won't wake
             # up spuriously too many times.
-            kwargs={'poll_interval':0.01})
+            kwargs={'poll_interval': 0.01})
         t.daemon = True  # In case this function raises.
         t.start()
-        if verbose: print("server running")
+        if verbose:
+            print("server running")
         return server, t
 
     def reap_server(self, server, thread):
-        if verbose: print("waiting for server")
+        if verbose:
+            print("waiting for server")
         server.shutdown()
         server.server_close()
         thread.join()
-        if verbose: print("done")
+        if verbose:
+            print("done")
 
     @contextmanager
     def reaped_server(self, hdlr):
@@ -256,7 +272,7 @@ class BaseThreadedNetworkedTests(unittest.TestCase):
 
             def cmd_AUTHENTICATE(self, tag, args):
                 self._send_tagged(tag, 'NO', 'unrecognized authentication '
-                        'type {}'.format(args[0]))
+                                  'type {}'.format(args[0]))
 
         with self.reaped_pair(MyServer) as (server, client):
             with self.assertRaises(imaplib.IMAP4.error):
@@ -290,13 +306,13 @@ class BaseThreadedNetworkedTests(unittest.TestCase):
             code, data = client.authenticate('MYAUTH', lambda x: b'fake')
             self.assertEqual(code, 'OK')
             self.assertEqual(server.response,
-                             b'ZmFrZQ==\r\n') #b64 encoded 'fake'
+                             b'ZmFrZQ==\r\n')  # b64 encoded 'fake'
 
         with self.reaped_pair(MyServer) as (server, client):
             code, data = client.authenticate('MYAUTH', lambda x: 'fake')
             self.assertEqual(code, 'OK')
             self.assertEqual(server.response,
-                             b'ZmFrZQ==\r\n') #b64 encoded 'fake'
+                             b'ZmFrZQ==\r\n')  # b64 encoded 'fake'
 
     @reap_threads
     def test_login_cram_md5(self):
@@ -307,9 +323,10 @@ class BaseThreadedNetworkedTests(unittest.TestCase):
 
             def cmd_AUTHENTICATE(self, tag, args):
                 self._send_textline('+ PDE4OTYuNjk3MTcwOTUyQHBvc3RvZmZpY2Uucm'
-                                       'VzdG9uLm1jaS5uZXQ=')
+                                    'VzdG9uLm1jaS5uZXQ=')
                 r = yield
-                if r ==  b'dGltIGYxY2E2YmU0NjRiOWVmYTFjY2E2ZmZkNmNmMmQ5ZjMy\r\n':
+                if (r == b'dGltIGYxY2E2YmU0NjRiOWVmYT'
+                         b'FjY2E2ZmZkNmNmMmQ5ZjMy\r\n'):
                     self._send_tagged(tag, 'OK', 'CRAM-MD5 successful')
                 else:
                     self._send_tagged(tag, 'NO', 'No access')
@@ -324,27 +341,45 @@ class BaseThreadedNetworkedTests(unittest.TestCase):
             ret, data = client.login_cram_md5("tim", b"tanstaaftanstaaf")
             self.assertEqual(ret, "OK")
 
-
     def test_linetoolong(self):
         class TooLongHandler(SimpleIMAPHandler):
             def handle(self):
                 # Send a very long response line
-                self.wfile.write(b'* OK ' + imaplib._MAXLINE*b'x' + b'\r\n')
+                self.wfile.write(b'* OK ' + imaplib._MAXLINE * b'x' + b'\r\n')
 
         with self.reaped_server(TooLongHandler) as server:
             self.assertRaises(imaplib.IMAP4.error,
                               self.imap_class, *server.server_address)
 
+    @reap_threads
+    def test_simple_with_statement(self):
+        # simplest call
+        with self.reaped_server(SimpleIMAPHandler) as server:
+            with self.imap_class(*server.server_address):
+                pass
 
-class ThreadedNetworkedTests(BaseThreadedNetworkedTests):
+    @reap_threads
+    def test_with_statement(self):
+        with self.reaped_server(SimpleIMAPHandler) as server:
+            with self.imap_class(*server.server_address) as imap:
+                imap.login('user', 'pass')
+                self.assertEqual(server.logged, 'user')
+            self.assertIsNone(server.logged)
 
-    server_class = socketserver.TCPServer
-    imap_class = imaplib.IMAP4
+    @reap_threads
+    def test_with_statement_logout(self):
+        # what happens if already logout in the block?
+        with self.reaped_server(SimpleIMAPHandler) as server:
+            with self.imap_class(*server.server_address) as imap:
+                imap.login('user', 'pass')
+                self.assertEqual(server.logged, 'user')
+                imap.logout()
+                self.assertIsNone(server.logged)
+            self.assertIsNone(server.logged)
 
 
 @unittest.skipUnless(ssl, "SSL not available")
-class ThreadedNetworkedTestsSSL(BaseThreadedNetworkedTests):
-
+class ThreadedNetworkedTestsSSL(ThreadedNetworkedTests):
     server_class = SecureTCPServer
     imap_class = IMAP4_SSL
 
@@ -355,8 +390,9 @@ class ThreadedNetworkedTestsSSL(BaseThreadedNetworkedTests):
         ssl_context.check_hostname = True
         ssl_context.load_verify_locations(CAFILE)
 
-        with self.assertRaisesRegex(ssl.CertificateError,
-                                    "hostname '127.0.0.1' doesn't match 'localhost'"):
+        with self.assertRaisesRegex(
+                ssl.CertificateError,
+                "hostname '127.0.0.1' doesn't match 'localhost'"):
             with self.reaped_server(SimpleIMAPHandler) as server:
                 client = self.imap_class(*server.server_address,
                                          ssl_context=ssl_context)
@@ -368,6 +404,8 @@ class ThreadedNetworkedTestsSSL(BaseThreadedNetworkedTests):
             client.shutdown()
 
 
+@unittest.skipUnless(
+    support.is_resource_enabled('network'), 'network resource disabled')
 class RemoteIMAPTest(unittest.TestCase):
     host = 'cyrus.andrew.cmu.edu'
     port = 143
@@ -401,6 +439,8 @@ class RemoteIMAPTest(unittest.TestCase):
 
 
 @unittest.skipUnless(ssl, "SSL not available")
+@unittest.skipUnless(
+    support.is_resource_enabled('network'), 'network resource disabled')
 class RemoteIMAP_STARTTLSTest(RemoteIMAPTest):
 
     def setUp(self):
@@ -454,7 +494,8 @@ class RemoteIMAP_SSLTest(RemoteIMAPTest):
 
     def test_logincapa_with_client_ssl_context(self):
         with transient_internet(self.host):
-            _server = self.imap_class(self.host, self.port, ssl_context=self.create_ssl_context())
+            _server = self.imap_class(
+                self.host, self.port, ssl_context=self.create_ssl_context())
             self.check_logincapa(_server)
 
     def test_logout(self):
@@ -465,35 +506,15 @@ class RemoteIMAP_SSLTest(RemoteIMAPTest):
 
     def test_ssl_context_certfile_exclusive(self):
         with transient_internet(self.host):
-            self.assertRaises(ValueError, self.imap_class, self.host, self.port,
-                              certfile=CERTFILE, ssl_context=self.create_ssl_context())
+            self.assertRaises(
+                ValueError, self.imap_class, self.host, self.port,
+                certfile=CERTFILE, ssl_context=self.create_ssl_context())
 
     def test_ssl_context_keyfile_exclusive(self):
         with transient_internet(self.host):
-            self.assertRaises(ValueError, self.imap_class, self.host, self.port,
-                              keyfile=CERTFILE, ssl_context=self.create_ssl_context())
-
-
-def load_tests(*args):
-    tests = [TestImaplib]
-
-    if support.is_resource_enabled('network'):
-        if ssl:
-            global CERTFILE, CAFILE
-            CERTFILE = os.path.join(os.path.dirname(__file__) or os.curdir,
-                                    "keycert3.pem")
-            if not os.path.exists(CERTFILE):
-                raise support.TestFailed("Can't read certificate files!")
-            CAFILE = os.path.join(os.path.dirname(__file__) or os.curdir,
-                                 "pycacert.pem")
-            if not os.path.exists(CAFILE):
-                raise support.TestFailed("Can't read CA file!")
-        tests.extend([
-            ThreadedNetworkedTests, ThreadedNetworkedTestsSSL,
-            RemoteIMAPTest, RemoteIMAP_SSLTest, RemoteIMAP_STARTTLSTest,
-        ])
-
-    return unittest.TestSuite([unittest.makeSuite(test) for test in tests])
+            self.assertRaises(
+                ValueError, self.imap_class, self.host, self.port,
+                keyfile=CERTFILE, ssl_context=self.create_ssl_context())
 
 
 if __name__ == "__main__":
diff --git a/Lib/test/test_imghdr.py b/Lib/test/test_imghdr.py
index 0ad4343f52..b54daf8e2c 100644
--- a/Lib/test/test_imghdr.py
+++ b/Lib/test/test_imghdr.py
@@ -16,7 +16,9 @@ TEST_FILES = (
     ('python.ras', 'rast'),
     ('python.sgi', 'rgb'),
     ('python.tiff', 'tiff'),
-    ('python.xbm', 'xbm')
+    ('python.xbm', 'xbm'),
+    ('python.webp', 'webp'),
+    ('python.exr', 'exr'),
 )
 
 class UnseekableIO(io.FileIO):
diff --git a/Lib/test/test_import.py b/Lib/test/test_import/__init__.py
index b4842c54b5..fd21fa29e7 100644
--- a/Lib/test/test_import.py
+++ b/Lib/test/test_import/__init__.py
@@ -568,7 +568,7 @@ class RelativeImportTests(unittest.TestCase):
 
     def test_relimport_star(self):
         # This will import * from .test_import.
-        from . import relimport
+        from .. import relimport
         self.assertTrue(hasattr(relimport, "RelativeImportTests"))
 
     def test_issue3221(self):
@@ -1068,6 +1068,46 @@ class ImportTracebackTests(unittest.TestCase):
                                        __isolated=False)
 
 
+class CircularImportTests(unittest.TestCase):
+
+    """See the docstrings of the modules being imported for the purpose of the
+    test."""
+
+    def tearDown(self):
+        """Make sure no modules pre-exist in sys.modules which are being used to
+        test."""
+        for key in list(sys.modules.keys()):
+            if key.startswith('test.test_import.data.circular_imports'):
+                del sys.modules[key]
+
+    def test_direct(self):
+        try:
+            import test.test_import.data.circular_imports.basic
+        except ImportError:
+            self.fail('circular import through relative imports failed')
+
+    def test_indirect(self):
+        try:
+            import test.test_import.data.circular_imports.indirect
+        except ImportError:
+            self.fail('relative import in module contributing to circular '
+                      'import failed')
+
+    def test_subpackage(self):
+        try:
+            import test.test_import.data.circular_imports.subpackage
+        except ImportError:
+            self.fail('circular import involving a subpackage failed')
+
+    def test_rebinding(self):
+        try:
+            import test.test_import.data.circular_imports.rebinding as rebinding
+        except ImportError:
+            self.fail('circular import with rebinding of module attribute failed')
+        from test.test_import.data.circular_imports.subpkg import util
+        self.assertIs(util.util, rebinding.util)
+
+
 if __name__ == '__main__':
     # Test needs to be a package, so we can do relative imports.
     unittest.main()
diff --git a/Lib/test/test_import/__main__.py b/Lib/test/test_import/__main__.py
new file mode 100644
index 0000000000..24f02a171a
--- /dev/null
+++ b/Lib/test/test_import/__main__.py
@@ -0,0 +1,3 @@
+import unittest
+
+unittest.main('test.test_import')
diff --git a/Lib/test/test_import/data/circular_imports/basic.py b/Lib/test/test_import/data/circular_imports/basic.py
new file mode 100644
index 0000000000..3e41e395db
--- /dev/null
+++ b/Lib/test/test_import/data/circular_imports/basic.py
@@ -0,0 +1,2 @@
+"""Circular imports through direct, relative imports."""
+from . import basic2
diff --git a/Lib/test/test_import/data/circular_imports/basic2.py b/Lib/test/test_import/data/circular_imports/basic2.py
new file mode 100644
index 0000000000..00bd2f29f3
--- /dev/null
+++ b/Lib/test/test_import/data/circular_imports/basic2.py
@@ -0,0 +1 @@
+from . import basic
diff --git a/Lib/test/test_import/data/circular_imports/indirect.py b/Lib/test/test_import/data/circular_imports/indirect.py
new file mode 100644
index 0000000000..6925788d60
--- /dev/null
+++ b/Lib/test/test_import/data/circular_imports/indirect.py
@@ -0,0 +1 @@
+from . import basic, basic2
diff --git a/Lib/test/test_import/data/circular_imports/rebinding.py b/Lib/test/test_import/data/circular_imports/rebinding.py
new file mode 100644
index 0000000000..2b77375559
--- /dev/null
+++ b/Lib/test/test_import/data/circular_imports/rebinding.py
@@ -0,0 +1,3 @@
+"""Test the binding of names when a circular import shares the same name as an
+attribute."""
+from .rebinding2 import util
diff --git a/Lib/test/test_import/data/circular_imports/rebinding2.py b/Lib/test/test_import/data/circular_imports/rebinding2.py
new file mode 100644
index 0000000000..57a9e6945d
--- /dev/null
+++ b/Lib/test/test_import/data/circular_imports/rebinding2.py
@@ -0,0 +1,3 @@
+from .subpkg import util
+from . import rebinding
+util = util.util
diff --git a/Lib/test/test_import/data/circular_imports/subpackage.py b/Lib/test/test_import/data/circular_imports/subpackage.py
new file mode 100644
index 0000000000..7b412f76fc
--- /dev/null
+++ b/Lib/test/test_import/data/circular_imports/subpackage.py
@@ -0,0 +1,2 @@
+"""Circular import involving a sub-package."""
+from .subpkg import subpackage2
diff --git a/Lib/test/test_import/data/circular_imports/subpkg/subpackage2.py b/Lib/test/test_import/data/circular_imports/subpkg/subpackage2.py
new file mode 100644
index 0000000000..17b893a1a2
--- /dev/null
+++ b/Lib/test/test_import/data/circular_imports/subpkg/subpackage2.py
@@ -0,0 +1,2 @@
+#from .util import util
+from .. import subpackage
diff --git a/Lib/test/test_import/data/circular_imports/subpkg/util.py b/Lib/test/test_import/data/circular_imports/subpkg/util.py
new file mode 100644
index 0000000000..343bd843b2
--- /dev/null
+++ b/Lib/test/test_import/data/circular_imports/subpkg/util.py
@@ -0,0 +1,2 @@
+def util():
+    pass
diff --git a/Lib/test/test_import/data/circular_imports/util.py b/Lib/test/test_import/data/circular_imports/util.py
new file mode 100644
index 0000000000..343bd843b2
--- /dev/null
+++ b/Lib/test/test_import/data/circular_imports/util.py
@@ -0,0 +1,2 @@
+def util():
+    pass
diff --git a/Lib/test/test_importlib/builtin/test_finder.py b/Lib/test/test_importlib/builtin/test_finder.py
index 934562feb6..a2e6e1edc3 100644
--- a/Lib/test/test_importlib/builtin/test_finder.py
+++ b/Lib/test/test_importlib/builtin/test_finder.py
@@ -1,21 +1,21 @@
 from .. import abc
 from .. import util
-from . import util as builtin_util
 
-frozen_machinery, source_machinery = util.import_importlib('importlib.machinery')
+machinery = util.import_importlib('importlib.machinery')
 
 import sys
 import unittest
 
 
+@unittest.skipIf(util.BUILTINS.good_name is None, 'no reasonable builtin module')
 class FindSpecTests(abc.FinderTests):
 
     """Test find_spec() for built-in modules."""
 
     def test_module(self):
         # Common case.
-        with util.uncache(builtin_util.NAME):
-            found = self.machinery.BuiltinImporter.find_spec(builtin_util.NAME)
+        with util.uncache(util.BUILTINS.good_name):
+            found = self.machinery.BuiltinImporter.find_spec(util.BUILTINS.good_name)
             self.assertTrue(found)
             self.assertEqual(found.origin, 'built-in')
 
@@ -39,23 +39,26 @@ class FindSpecTests(abc.FinderTests):
 
     def test_ignore_path(self):
         # The value for 'path' should always trigger a failed import.
-        with util.uncache(builtin_util.NAME):
-            spec = self.machinery.BuiltinImporter.find_spec(builtin_util.NAME,
+        with util.uncache(util.BUILTINS.good_name):
+            spec = self.machinery.BuiltinImporter.find_spec(util.BUILTINS.good_name,
                                                             ['pkg'])
             self.assertIsNone(spec)
 
-Frozen_FindSpecTests, Source_FindSpecTests = util.test_both(FindSpecTests,
-        machinery=[frozen_machinery, source_machinery])
 
+(Frozen_FindSpecTests,
+ Source_FindSpecTests
+ ) = util.test_both(FindSpecTests, machinery=machinery)
 
+
+@unittest.skipIf(util.BUILTINS.good_name is None, 'no reasonable builtin module')
 class FinderTests(abc.FinderTests):
 
     """Test find_module() for built-in modules."""
 
     def test_module(self):
         # Common case.
-        with util.uncache(builtin_util.NAME):
-            found = self.machinery.BuiltinImporter.find_module(builtin_util.NAME)
+        with util.uncache(util.BUILTINS.good_name):
+            found = self.machinery.BuiltinImporter.find_module(util.BUILTINS.good_name)
             self.assertTrue(found)
             self.assertTrue(hasattr(found, 'load_module'))
 
@@ -72,13 +75,15 @@ class FinderTests(abc.FinderTests):
 
     def test_ignore_path(self):
         # The value for 'path' should always trigger a failed import.
-        with util.uncache(builtin_util.NAME):
-            loader = self.machinery.BuiltinImporter.find_module(builtin_util.NAME,
+        with util.uncache(util.BUILTINS.good_name):
+            loader = self.machinery.BuiltinImporter.find_module(util.BUILTINS.good_name,
                                                             ['pkg'])
             self.assertIsNone(loader)
 
-Frozen_FinderTests, Source_FinderTests = util.test_both(FinderTests,
-        machinery=[frozen_machinery, source_machinery])
+
+(Frozen_FinderTests,
+ Source_FinderTests
+ ) = util.test_both(FinderTests, machinery=machinery)
 
 
 if __name__ == '__main__':
diff --git a/Lib/test/test_importlib/builtin/test_loader.py b/Lib/test/test_importlib/builtin/test_loader.py
index 1f8357402f..1684ab6eb4 100644
--- a/Lib/test/test_importlib/builtin/test_loader.py
+++ b/Lib/test/test_importlib/builtin/test_loader.py
@@ -1,14 +1,13 @@
 from .. import abc
 from .. import util
-from . import util as builtin_util
 
-frozen_machinery, source_machinery = util.import_importlib('importlib.machinery')
+machinery = util.import_importlib('importlib.machinery')
 
 import sys
 import types
 import unittest
 
-
+@unittest.skipIf(util.BUILTINS.good_name is None, 'no reasonable builtin module')
 class LoaderTests(abc.LoaderTests):
 
     """Test load_module() for built-in modules."""
@@ -29,8 +28,8 @@ class LoaderTests(abc.LoaderTests):
 
     def test_module(self):
         # Common case.
-        with util.uncache(builtin_util.NAME):
-            module = self.load_module(builtin_util.NAME)
+        with util.uncache(util.BUILTINS.good_name):
+            module = self.load_module(util.BUILTINS.good_name)
             self.verify(module)
 
     # Built-in modules cannot be a package.
@@ -41,9 +40,9 @@ class LoaderTests(abc.LoaderTests):
 
     def test_module_reuse(self):
         # Test that the same module is used in a reload.
-        with util.uncache(builtin_util.NAME):
-            module1 = self.load_module(builtin_util.NAME)
-            module2 = self.load_module(builtin_util.NAME)
+        with util.uncache(util.BUILTINS.good_name):
+            module1 = self.load_module(util.BUILTINS.good_name)
+            module2 = self.load_module(util.BUILTINS.good_name)
             self.assertIs(module1, module2)
 
     def test_unloadable(self):
@@ -66,40 +65,44 @@ class LoaderTests(abc.LoaderTests):
         self.assertEqual(cm.exception.name, module_name)
 
 
-Frozen_LoaderTests, Source_LoaderTests = util.test_both(LoaderTests,
-        machinery=[frozen_machinery, source_machinery])
+(Frozen_LoaderTests,
+ Source_LoaderTests
+ ) = util.test_both(LoaderTests, machinery=machinery)
 
 
+@unittest.skipIf(util.BUILTINS.good_name is None, 'no reasonable builtin module')
 class InspectLoaderTests:
 
     """Tests for InspectLoader methods for BuiltinImporter."""
 
     def test_get_code(self):
         # There is no code object.
-        result = self.machinery.BuiltinImporter.get_code(builtin_util.NAME)
+        result = self.machinery.BuiltinImporter.get_code(util.BUILTINS.good_name)
         self.assertIsNone(result)
 
     def test_get_source(self):
         # There is no source.
-        result = self.machinery.BuiltinImporter.get_source(builtin_util.NAME)
+        result = self.machinery.BuiltinImporter.get_source(util.BUILTINS.good_name)
         self.assertIsNone(result)
 
     def test_is_package(self):
         # Cannot be a package.
-        result = self.machinery.BuiltinImporter.is_package(builtin_util.NAME)
+        result = self.machinery.BuiltinImporter.is_package(util.BUILTINS.good_name)
         self.assertFalse(result)
 
+    @unittest.skipIf(util.BUILTINS.bad_name is None, 'all modules are built in')
     def test_not_builtin(self):
         # Modules not built-in should raise ImportError.
         for meth_name in ('get_code', 'get_source', 'is_package'):
             method = getattr(self.machinery.BuiltinImporter, meth_name)
         with self.assertRaises(ImportError) as cm:
-            method(builtin_util.BAD_NAME)
-        self.assertRaises(builtin_util.BAD_NAME)
+            method(util.BUILTINS.bad_name)
+        self.assertRaises(util.BUILTINS.bad_name)
+
 
-Frozen_InspectLoaderTests, Source_InspectLoaderTests = util.test_both(
-        InspectLoaderTests,
-        machinery=[frozen_machinery, source_machinery])
+(Frozen_InspectLoaderTests,
+ Source_InspectLoaderTests
+ ) = util.test_both(InspectLoaderTests, machinery=machinery)
 
 
 if __name__ == '__main__':
diff --git a/Lib/test/test_importlib/builtin/util.py b/Lib/test/test_importlib/builtin/util.py
deleted file mode 100644
index 5704699ee2..0000000000
--- a/Lib/test/test_importlib/builtin/util.py
+++ /dev/null
@@ -1,7 +0,0 @@
-import sys
-
-assert 'errno' in sys.builtin_module_names
-NAME = 'errno'
-
-assert 'importlib' not in sys.builtin_module_names
-BAD_NAME = 'importlib'
diff --git a/Lib/test/test_importlib/extension/test_case_sensitivity.py b/Lib/test/test_importlib/extension/test_case_sensitivity.py
index bb2528e626..c7d6ca61f8 100644
--- a/Lib/test/test_importlib/extension/test_case_sensitivity.py
+++ b/Lib/test/test_importlib/extension/test_case_sensitivity.py
@@ -4,22 +4,21 @@ from test import support
 import unittest
 
 from .. import util
-from . import util as ext_util
 
-frozen_machinery, source_machinery = util.import_importlib('importlib.machinery')
+machinery = util.import_importlib('importlib.machinery')
 
 
 # XXX find_spec tests
 
-@unittest.skipIf(ext_util.FILENAME is None, '_testcapi not available')
+@unittest.skipIf(util.EXTENSIONS.filename is None, '_testcapi not available')
 @util.case_insensitive_tests
 class ExtensionModuleCaseSensitivityTest:
 
     def find_module(self):
-        good_name = ext_util.NAME
+        good_name = util.EXTENSIONS.name
         bad_name = good_name.upper()
         assert good_name != bad_name
-        finder = self.machinery.FileFinder(ext_util.PATH,
+        finder = self.machinery.FileFinder(util.EXTENSIONS.path,
                                           (self.machinery.ExtensionFileLoader,
                                            self.machinery.EXTENSION_SUFFIXES))
         return finder.find_module(bad_name)
@@ -42,9 +41,10 @@ class ExtensionModuleCaseSensitivityTest:
             loader = self.find_module()
             self.assertTrue(hasattr(loader, 'load_module'))
 
-Frozen_ExtensionCaseSensitivity, Source_ExtensionCaseSensitivity = util.test_both(
-        ExtensionModuleCaseSensitivityTest,
-        machinery=[frozen_machinery, source_machinery])
+
+(Frozen_ExtensionCaseSensitivity,
+ Source_ExtensionCaseSensitivity
+ ) = util.test_both(ExtensionModuleCaseSensitivityTest, machinery=machinery)
 
 
 if __name__ == '__main__':
diff --git a/Lib/test/test_importlib/extension/test_finder.py b/Lib/test/test_importlib/extension/test_finder.py
index 990f29c4e5..71bf67febd 100644
--- a/Lib/test/test_importlib/extension/test_finder.py
+++ b/Lib/test/test_importlib/extension/test_finder.py
@@ -1,8 +1,7 @@
 from .. import abc
-from .. import util as test_util
-from . import util
+from .. import util
 
-machinery = test_util.import_importlib('importlib.machinery')
+machinery = util.import_importlib('importlib.machinery')
 
 import unittest
 import warnings
@@ -14,7 +13,7 @@ class FinderTests(abc.FinderTests):
     """Test the finder for extension modules."""
 
     def find_module(self, fullname):
-        importer = self.machinery.FileFinder(util.PATH,
+        importer = self.machinery.FileFinder(util.EXTENSIONS.path,
                                             (self.machinery.ExtensionFileLoader,
                                              self.machinery.EXTENSION_SUFFIXES))
         with warnings.catch_warnings():
@@ -22,7 +21,7 @@ class FinderTests(abc.FinderTests):
             return importer.find_module(fullname)
 
     def test_module(self):
-        self.assertTrue(self.find_module(util.NAME))
+        self.assertTrue(self.find_module(util.EXTENSIONS.name))
 
     # No extension module as an __init__ available for testing.
     test_package = test_package_in_package = None
@@ -36,8 +35,10 @@ class FinderTests(abc.FinderTests):
     def test_failure(self):
         self.assertIsNone(self.find_module('asdfjkl;'))
 
-Frozen_FinderTests, Source_FinderTests = test_util.test_both(
-        FinderTests, machinery=machinery)
+
+(Frozen_FinderTests,
+ Source_FinderTests
+ ) = util.test_both(FinderTests, machinery=machinery)
 
 
 if __name__ == '__main__':
diff --git a/Lib/test/test_importlib/extension/test_loader.py b/Lib/test/test_importlib/extension/test_loader.py
index fd9abf269b..aefd050ff0 100644
--- a/Lib/test/test_importlib/extension/test_loader.py
+++ b/Lib/test/test_importlib/extension/test_loader.py
@@ -1,4 +1,3 @@
-from . import util as ext_util
 from .. import abc
 from .. import util
 
@@ -15,8 +14,8 @@ class LoaderTests(abc.LoaderTests):
     """Test load_module() for extension modules."""
 
     def setUp(self):
-        self.loader = self.machinery.ExtensionFileLoader(ext_util.NAME,
-                                                         ext_util.FILEPATH)
+        self.loader = self.machinery.ExtensionFileLoader(util.EXTENSIONS.name,
+                                                         util.EXTENSIONS.file_path)
 
     def load_module(self, fullname):
         return self.loader.load_module(fullname)
@@ -29,23 +28,23 @@ class LoaderTests(abc.LoaderTests):
             self.load_module('XXX')
 
     def test_equality(self):
-        other = self.machinery.ExtensionFileLoader(ext_util.NAME,
-                                                   ext_util.FILEPATH)
+        other = self.machinery.ExtensionFileLoader(util.EXTENSIONS.name,
+                                                   util.EXTENSIONS.file_path)
         self.assertEqual(self.loader, other)
 
     def test_inequality(self):
-        other = self.machinery.ExtensionFileLoader('_' + ext_util.NAME,
-                                                   ext_util.FILEPATH)
+        other = self.machinery.ExtensionFileLoader('_' + util.EXTENSIONS.name,
+                                                   util.EXTENSIONS.file_path)
         self.assertNotEqual(self.loader, other)
 
     def test_module(self):
-        with util.uncache(ext_util.NAME):
-            module = self.load_module(ext_util.NAME)
-            for attr, value in [('__name__', ext_util.NAME),
-                                ('__file__', ext_util.FILEPATH),
+        with util.uncache(util.EXTENSIONS.name):
+            module = self.load_module(util.EXTENSIONS.name)
+            for attr, value in [('__name__', util.EXTENSIONS.name),
+                                ('__file__', util.EXTENSIONS.file_path),
                                 ('__package__', '')]:
                 self.assertEqual(getattr(module, attr), value)
-            self.assertIn(ext_util.NAME, sys.modules)
+            self.assertIn(util.EXTENSIONS.name, sys.modules)
             self.assertIsInstance(module.__loader__,
                                   self.machinery.ExtensionFileLoader)
 
@@ -56,9 +55,9 @@ class LoaderTests(abc.LoaderTests):
     test_lacking_parent = None
 
     def test_module_reuse(self):
-        with util.uncache(ext_util.NAME):
-            module1 = self.load_module(ext_util.NAME)
-            module2 = self.load_module(ext_util.NAME)
+        with util.uncache(util.EXTENSIONS.name):
+            module1 = self.load_module(util.EXTENSIONS.name)
+            module2 = self.load_module(util.EXTENSIONS.name)
             self.assertIs(module1, module2)
 
     # No easy way to trigger a failure after a successful import.
@@ -71,14 +70,15 @@ class LoaderTests(abc.LoaderTests):
         self.assertEqual(cm.exception.name, name)
 
     def test_is_package(self):
-        self.assertFalse(self.loader.is_package(ext_util.NAME))
+        self.assertFalse(self.loader.is_package(util.EXTENSIONS.name))
         for suffix in self.machinery.EXTENSION_SUFFIXES:
             path = os.path.join('some', 'path', 'pkg', '__init__' + suffix)
             loader = self.machinery.ExtensionFileLoader('pkg', path)
             self.assertTrue(loader.is_package('pkg'))
 
-Frozen_LoaderTests, Source_LoaderTests = util.test_both(
-        LoaderTests, machinery=machinery)
+(Frozen_LoaderTests,
+ Source_LoaderTests
+ ) = util.test_both(LoaderTests, machinery=machinery)
 
 
 
diff --git a/Lib/test/test_importlib/extension/test_path_hook.py b/Lib/test/test_importlib/extension/test_path_hook.py
index 49d6734711..8f4b8bb161 100644
--- a/Lib/test/test_importlib/extension/test_path_hook.py
+++ b/Lib/test/test_importlib/extension/test_path_hook.py
@@ -1,7 +1,6 @@
-from .. import util as test_util
-from . import util
+from .. import util
 
-machinery = test_util.import_importlib('importlib.machinery')
+machinery = util.import_importlib('importlib.machinery')
 
 import collections
 import sys
@@ -22,10 +21,12 @@ class PathHookTests:
     def test_success(self):
         # Path hook should handle a directory where a known extension module
         # exists.
-        self.assertTrue(hasattr(self.hook(util.PATH), 'find_module'))
+        self.assertTrue(hasattr(self.hook(util.EXTENSIONS.path), 'find_module'))
 
-Frozen_PathHooksTests, Source_PathHooksTests = test_util.test_both(
-        PathHookTests, machinery=machinery)
+
+(Frozen_PathHooksTests,
+ Source_PathHooksTests
+ ) = util.test_both(PathHookTests, machinery=machinery)
 
 
 if __name__ == '__main__':
diff --git a/Lib/test/test_importlib/extension/util.py b/Lib/test/test_importlib/extension/util.py
deleted file mode 100644
index 8d089f0d7c..0000000000
--- a/Lib/test/test_importlib/extension/util.py
+++ /dev/null
@@ -1,19 +0,0 @@
-from importlib import machinery
-import os
-import sys
-
-PATH = None
-EXT = None
-FILENAME = None
-NAME = '_testcapi'
-try:
-    for PATH in sys.path:
-        for EXT in machinery.EXTENSION_SUFFIXES:
-            FILENAME = NAME + EXT
-            FILEPATH = os.path.join(PATH, FILENAME)
-            if os.path.exists(os.path.join(PATH, FILENAME)):
-                raise StopIteration
-    else:
-        PATH = EXT = FILENAME = FILEPATH = None
-except StopIteration:
-    pass
diff --git a/Lib/test/test_importlib/frozen/test_finder.py b/Lib/test/test_importlib/frozen/test_finder.py
index f9f97f3851..519aa027d6 100644
--- a/Lib/test/test_importlib/frozen/test_finder.py
+++ b/Lib/test/test_importlib/frozen/test_finder.py
@@ -37,8 +37,10 @@ class FindSpecTests(abc.FinderTests):
         spec = self.find('<not real>')
         self.assertIsNone(spec)
 
-Frozen_FindSpecTests, Source_FindSpecTests = util.test_both(FindSpecTests,
-                                                            machinery=machinery)
+
+(Frozen_FindSpecTests,
+ Source_FindSpecTests
+ ) = util.test_both(FindSpecTests, machinery=machinery)
 
 
 class FinderTests(abc.FinderTests):
@@ -72,8 +74,10 @@ class FinderTests(abc.FinderTests):
         loader = self.find('<not real>')
         self.assertIsNone(loader)
 
-Frozen_FinderTests, Source_FinderTests = util.test_both(FinderTests,
-                                                        machinery=machinery)
+
+(Frozen_FinderTests,
+ Source_FinderTests
+ ) = util.test_both(FinderTests, machinery=machinery)
 
 
 if __name__ == '__main__':
diff --git a/Lib/test/test_importlib/frozen/test_loader.py b/Lib/test/test_importlib/frozen/test_loader.py
index 7c0146456d..603c7d7b19 100644
--- a/Lib/test/test_importlib/frozen/test_loader.py
+++ b/Lib/test/test_importlib/frozen/test_loader.py
@@ -85,8 +85,10 @@ class ExecModuleTests(abc.LoaderTests):
             self.exec_module('_not_real')
         self.assertEqual(cm.exception.name, '_not_real')
 
-Frozen_ExecModuleTests, Source_ExecModuleTests = util.test_both(ExecModuleTests,
-                                                        machinery=machinery)
+
+(Frozen_ExecModuleTests,
+ Source_ExecModuleTests
+ ) = util.test_both(ExecModuleTests, machinery=machinery)
 
 
 class LoaderTests(abc.LoaderTests):
@@ -175,8 +177,10 @@ class LoaderTests(abc.LoaderTests):
             self.machinery.FrozenImporter.load_module('_not_real')
         self.assertEqual(cm.exception.name, '_not_real')
 
-Frozen_LoaderTests, Source_LoaderTests = util.test_both(LoaderTests,
-                                                        machinery=machinery)
+
+(Frozen_LoaderTests,
+ Source_LoaderTests
+ ) = util.test_both(LoaderTests, machinery=machinery)
 
 
 class InspectLoaderTests:
@@ -214,8 +218,9 @@ class InspectLoaderTests:
                 method('importlib')
             self.assertEqual(cm.exception.name, 'importlib')
 
-Frozen_ILTests, Source_ILTests = util.test_both(InspectLoaderTests,
-                                                machinery=machinery)
+(Frozen_ILTests,
+ Source_ILTests
+ ) = util.test_both(InspectLoaderTests, machinery=machinery)
 
 
 if __name__ == '__main__':
diff --git a/Lib/test/test_importlib/import_/test___loader__.py b/Lib/test/test_importlib/import_/test___loader__.py
index 6df80101fa..4b18093cf9 100644
--- a/Lib/test/test_importlib/import_/test___loader__.py
+++ b/Lib/test/test_importlib/import_/test___loader__.py
@@ -4,7 +4,6 @@ import types
 import unittest
 
 from .. import util
-from . import util as import_util
 
 
 class SpecLoaderMock:
@@ -12,6 +11,9 @@ class SpecLoaderMock:
     def find_spec(self, fullname, path=None, target=None):
         return machinery.ModuleSpec(fullname, self)
 
+    def create_module(self, spec):
+        return None
+
     def exec_module(self, module):
         pass
 
@@ -24,8 +26,10 @@ class SpecLoaderAttributeTests:
             module = self.__import__('blah')
         self.assertEqual(loader, module.__loader__)
 
-Frozen_SpecTests, Source_SpecTests = util.test_both(
-        SpecLoaderAttributeTests, __import__=import_util.__import__)
+
+(Frozen_SpecTests,
+ Source_SpecTests
+ ) = util.test_both(SpecLoaderAttributeTests, __import__=util.__import__)
 
 
 class LoaderMock:
@@ -62,8 +66,9 @@ class LoaderAttributeTests:
         self.assertEqual(loader, module.__loader__)
 
 
-Frozen_Tests, Source_Tests = util.test_both(LoaderAttributeTests,
-                                            __import__=import_util.__import__)
+(Frozen_Tests,
+ Source_Tests
+ ) = util.test_both(LoaderAttributeTests, __import__=util.__import__)
 
 
 if __name__ == '__main__':
diff --git a/Lib/test/test_importlib/import_/test___package__.py b/Lib/test/test_importlib/import_/test___package__.py
index 2e19725680..c7d3a2a204 100644
--- a/Lib/test/test_importlib/import_/test___package__.py
+++ b/Lib/test/test_importlib/import_/test___package__.py
@@ -6,7 +6,6 @@ of using the typical __path__/__name__ test).
 """
 import unittest
 from .. import util
-from . import util as import_util
 
 
 class Using__package__:
@@ -70,17 +69,23 @@ class Using__package__:
         with self.assertRaises(TypeError):
             self.__import__('', globals, {}, ['relimport'], 1)
 
+
 class Using__package__PEP302(Using__package__):
     mock_modules = util.mock_modules
 
-Frozen_UsingPackagePEP302, Source_UsingPackagePEP302 = util.test_both(
-        Using__package__PEP302, __import__=import_util.__import__)
 
-class Using__package__PEP302(Using__package__):
+(Frozen_UsingPackagePEP302,
+ Source_UsingPackagePEP302
+ ) = util.test_both(Using__package__PEP302, __import__=util.__import__)
+
+
+class Using__package__PEP451(Using__package__):
     mock_modules = util.mock_spec
 
-Frozen_UsingPackagePEP451, Source_UsingPackagePEP451 = util.test_both(
-        Using__package__PEP302, __import__=import_util.__import__)
+
+(Frozen_UsingPackagePEP451,
+ Source_UsingPackagePEP451
+ ) = util.test_both(Using__package__PEP451, __import__=util.__import__)
 
 
 class Setting__package__:
@@ -95,7 +100,7 @@ class Setting__package__:
 
     """
 
-    __import__ = import_util.__import__[1]
+    __import__ = util.__import__['Source']
 
     # [top-level]
     def test_top_level(self):
diff --git a/Lib/test/test_importlib/import_/test_api.py b/Lib/test/test_importlib/import_/test_api.py
index 439c105e9b..7069d9e58d 100644
--- a/Lib/test/test_importlib/import_/test_api.py
+++ b/Lib/test/test_importlib/import_/test_api.py
@@ -1,5 +1,4 @@
 from .. import util
-from . import util as import_util
 
 from importlib import machinery
 import sys
@@ -18,6 +17,10 @@ class BadSpecFinderLoader:
             return spec
 
     @staticmethod
+    def create_module(spec):
+        return None
+
+    @staticmethod
     def exec_module(module):
         if module.__name__ == SUBMOD_NAME:
             raise ImportError('I cannot be loaded!')
@@ -79,15 +82,19 @@ class APITest:
 class OldAPITests(APITest):
     bad_finder_loader = BadLoaderFinder
 
-Frozen_OldAPITests, Source_OldAPITests = util.test_both(
-        OldAPITests, __import__=import_util.__import__)
+
+(Frozen_OldAPITests,
+ Source_OldAPITests
+ ) = util.test_both(OldAPITests, __import__=util.__import__)
 
 
 class SpecAPITests(APITest):
     bad_finder_loader = BadSpecFinderLoader
 
-Frozen_SpecAPITests, Source_SpecAPITests = util.test_both(
-        SpecAPITests, __import__=import_util.__import__)
+
+(Frozen_SpecAPITests,
+ Source_SpecAPITests
+ ) = util.test_both(SpecAPITests, __import__=util.__import__)
 
 
 if __name__ == '__main__':
diff --git a/Lib/test/test_importlib/import_/test_caching.py b/Lib/test/test_importlib/import_/test_caching.py
index c292ee4ac2..8079add5b2 100644
--- a/Lib/test/test_importlib/import_/test_caching.py
+++ b/Lib/test/test_importlib/import_/test_caching.py
@@ -1,6 +1,5 @@
 """Test that sys.modules is used properly by import."""
 from .. import util
-from . import util as import_util
 import sys
 from types import MethodType
 import unittest
@@ -39,15 +38,17 @@ class UseCache:
                 self.__import__(name)
             self.assertEqual(cm.exception.name, name)
 
-Frozen_UseCache, Source_UseCache = util.test_both(
-        UseCache, __import__=import_util.__import__)
+
+(Frozen_UseCache,
+ Source_UseCache
+ ) = util.test_both(UseCache, __import__=util.__import__)
 
 
 class ImportlibUseCache(UseCache, unittest.TestCase):
 
     # Pertinent only to PEP 302; exec_module() doesn't return a module.
 
-    __import__ = import_util.__import__[1]
+    __import__ = util.__import__['Source']
 
     def create_mock(self, *names, return_=None):
         mock = util.mock_modules(*names)
diff --git a/Lib/test/test_importlib/import_/test_fromlist.py b/Lib/test/test_importlib/import_/test_fromlist.py
index a755b75a73..80454655ad 100644
--- a/Lib/test/test_importlib/import_/test_fromlist.py
+++ b/Lib/test/test_importlib/import_/test_fromlist.py
@@ -1,6 +1,5 @@
 """Test that the semantics relating to the 'fromlist' argument are correct."""
 from .. import util
-from . import util as import_util
 import unittest
 
 
@@ -29,8 +28,10 @@ class ReturnValue:
                 module = self.__import__('pkg.module', fromlist=['attr'])
                 self.assertEqual(module.__name__, 'pkg.module')
 
-Frozen_ReturnValue, Source_ReturnValue = util.test_both(
-        ReturnValue, __import__=import_util.__import__)
+
+(Frozen_ReturnValue,
+ Source_ReturnValue
+ ) = util.test_both(ReturnValue, __import__=util.__import__)
 
 
 class HandlingFromlist:
@@ -121,8 +122,10 @@ class HandlingFromlist:
                 self.assertEqual(module.module1.__name__, 'pkg.module1')
                 self.assertEqual(module.module2.__name__, 'pkg.module2')
 
-Frozen_FromList, Source_FromList = util.test_both(
-        HandlingFromlist, __import__=import_util.__import__)
+
+(Frozen_FromList,
+ Source_FromList
+ ) = util.test_both(HandlingFromlist, __import__=util.__import__)
 
 
 if __name__ == '__main__':
diff --git a/Lib/test/test_importlib/import_/test_meta_path.py b/Lib/test/test_importlib/import_/test_meta_path.py
index 5eeb1458d3..c452cdd063 100644
--- a/Lib/test/test_importlib/import_/test_meta_path.py
+++ b/Lib/test/test_importlib/import_/test_meta_path.py
@@ -1,5 +1,4 @@
 from .. import util
-from . import util as import_util
 import importlib._bootstrap
 import sys
 from types import MethodType
@@ -46,8 +45,10 @@ class CallingOrder:
                 self.assertEqual(len(w), 1)
                 self.assertTrue(issubclass(w[-1].category, ImportWarning))
 
-Frozen_CallingOrder, Source_CallingOrder = util.test_both(
-        CallingOrder, __import__=import_util.__import__)
+
+(Frozen_CallingOrder,
+ Source_CallingOrder
+ ) = util.test_both(CallingOrder, __import__=util.__import__)
 
 
 class CallSignature:
@@ -100,19 +101,25 @@ class CallSignature:
                 self.assertEqual(args[0], mod_name)
                 self.assertIs(args[1], path)
 
+
 class CallSignaturePEP302(CallSignature):
     mock_modules = util.mock_modules
     finder_name = 'find_module'
 
-Frozen_CallSignaturePEP302, Source_CallSignaturePEP302 = util.test_both(
-        CallSignaturePEP302, __import__=import_util.__import__)
+
+(Frozen_CallSignaturePEP302,
+ Source_CallSignaturePEP302
+ ) = util.test_both(CallSignaturePEP302, __import__=util.__import__)
+
 
 class CallSignaturePEP451(CallSignature):
     mock_modules = util.mock_spec
     finder_name = 'find_spec'
 
-Frozen_CallSignaturePEP451, Source_CallSignaturePEP451 = util.test_both(
-        CallSignaturePEP451, __import__=import_util.__import__)
+
+(Frozen_CallSignaturePEP451,
+ Source_CallSignaturePEP451
+ ) = util.test_both(CallSignaturePEP451, __import__=util.__import__)
 
 
 if __name__ == '__main__':
diff --git a/Lib/test/test_importlib/import_/test_packages.py b/Lib/test/test_importlib/import_/test_packages.py
index 55a5d14985..3755b84a1a 100644
--- a/Lib/test/test_importlib/import_/test_packages.py
+++ b/Lib/test/test_importlib/import_/test_packages.py
@@ -1,5 +1,4 @@
 from .. import util
-from . import util as import_util
 import sys
 import unittest
 import importlib
@@ -102,8 +101,10 @@ class ParentModuleTests:
                 finally:
                     support.unload(subname)
 
-Frozen_ParentTests, Source_ParentTests = util.test_both(
-        ParentModuleTests, __import__=import_util.__import__)
+
+(Frozen_ParentTests,
+ Source_ParentTests
+ ) = util.test_both(ParentModuleTests, __import__=util.__import__)
 
 
 if __name__ == '__main__':
diff --git a/Lib/test/test_importlib/import_/test_path.py b/Lib/test/test_importlib/import_/test_path.py
index 1274f8cb9e..9a3c4fe877 100644
--- a/Lib/test/test_importlib/import_/test_path.py
+++ b/Lib/test/test_importlib/import_/test_path.py
@@ -1,11 +1,11 @@
 from .. import util
-from . import util as import_util
 
 importlib = util.import_importlib('importlib')
 machinery = util.import_importlib('importlib.machinery')
 
 import os
 import sys
+import tempfile
 from types import ModuleType
 import unittest
 import warnings
@@ -58,7 +58,7 @@ class FinderTests:
         module = '<test module>'
         path = '<test path>'
         importer = util.mock_spec(module)
-        hook = import_util.mock_path_hook(path, importer=importer)
+        hook = util.mock_path_hook(path, importer=importer)
         with util.import_state(path_hooks=[hook]):
             loader = self.machinery.PathFinder.find_module(module, [path])
             self.assertIs(loader, importer)
@@ -83,7 +83,7 @@ class FinderTests:
         path = ''
         module = '<test module>'
         importer = util.mock_spec(module)
-        hook = import_util.mock_path_hook(os.getcwd(), importer=importer)
+        hook = util.mock_path_hook(os.getcwd(), importer=importer)
         with util.import_state(path=[path], path_hooks=[hook]):
             loader = self.machinery.PathFinder.find_module(module)
             self.assertIs(loader, importer)
@@ -112,8 +112,69 @@ class FinderTests:
             if email is not missing:
                 sys.modules['email'] = email
 
-Frozen_FinderTests, Source_FinderTests = util.test_both(
-        FinderTests, importlib=importlib, machinery=machinery)
+    def test_finder_with_find_module(self):
+        class TestFinder:
+            def find_module(self, fullname):
+                return self.to_return
+        failing_finder = TestFinder()
+        failing_finder.to_return = None
+        path = 'testing path'
+        with util.import_state(path_importer_cache={path: failing_finder}):
+            self.assertIsNone(
+                    self.machinery.PathFinder.find_spec('whatever', [path]))
+        success_finder = TestFinder()
+        success_finder.to_return = __loader__
+        with util.import_state(path_importer_cache={path: success_finder}):
+            spec = self.machinery.PathFinder.find_spec('whatever', [path])
+        self.assertEqual(spec.loader, __loader__)
+
+    def test_finder_with_find_loader(self):
+        class TestFinder:
+            loader = None
+            portions = []
+            def find_loader(self, fullname):
+                return self.loader, self.portions
+        path = 'testing path'
+        with util.import_state(path_importer_cache={path: TestFinder()}):
+            self.assertIsNone(
+                    self.machinery.PathFinder.find_spec('whatever', [path]))
+        success_finder = TestFinder()
+        success_finder.loader = __loader__
+        with util.import_state(path_importer_cache={path: success_finder}):
+            spec = self.machinery.PathFinder.find_spec('whatever', [path])
+        self.assertEqual(spec.loader, __loader__)
+
+    def test_finder_with_find_spec(self):
+        class TestFinder:
+            spec = None
+            def find_spec(self, fullname, target=None):
+                return self.spec
+        path = 'testing path'
+        with util.import_state(path_importer_cache={path: TestFinder()}):
+            self.assertIsNone(
+                    self.machinery.PathFinder.find_spec('whatever', [path]))
+        success_finder = TestFinder()
+        success_finder.spec = self.machinery.ModuleSpec('whatever', __loader__)
+        with util.import_state(path_importer_cache={path: success_finder}):
+            got = self.machinery.PathFinder.find_spec('whatever', [path])
+        self.assertEqual(got, success_finder.spec)
+
+    @unittest.skipIf(sys.platform == 'win32', "cwd can't not exist on Windows")
+    def test_deleted_cwd(self):
+        # Issue #22834
+        self.addCleanup(os.chdir, os.getcwd())
+        with tempfile.TemporaryDirectory() as path:
+            os.chdir(path)
+        with util.import_state(path=['']):
+            # Do not want FileNotFoundError raised.
+            self.assertIsNone(self.machinery.PathFinder.find_spec('whatever'))
+
+
+
+
+(Frozen_FinderTests,
+ Source_FinderTests
+ ) = util.test_both(FinderTests, importlib=importlib, machinery=machinery)
 
 
 class PathEntryFinderTests:
@@ -136,8 +197,10 @@ class PathEntryFinderTests:
                                path_hooks=[Finder]):
             self.machinery.PathFinder.find_spec('importlib')
 
-Frozen_PEFTests, Source_PEFTests = util.test_both(
-        PathEntryFinderTests, machinery=machinery)
+
+(Frozen_PEFTests,
+ Source_PEFTests
+ ) = util.test_both(PathEntryFinderTests, machinery=machinery)
 
 
 if __name__ == '__main__':
diff --git a/Lib/test/test_importlib/import_/test_relative_imports.py b/Lib/test/test_importlib/import_/test_relative_imports.py
index b216e9cc13..28bb6f7c0c 100644
--- a/Lib/test/test_importlib/import_/test_relative_imports.py
+++ b/Lib/test/test_importlib/import_/test_relative_imports.py
@@ -1,6 +1,5 @@
 """Test relative imports (PEP 328)."""
 from .. import util
-from . import util as import_util
 import sys
 import unittest
 
@@ -208,8 +207,10 @@ class RelativeImports:
         with self.assertRaises(KeyError):
             self.__import__('sys', level=1)
 
-Frozen_RelativeImports, Source_RelativeImports = util.test_both(
-        RelativeImports, __import__=import_util.__import__)
+
+(Frozen_RelativeImports,
+ Source_RelativeImports
+ ) = util.test_both(RelativeImports, __import__=util.__import__)
 
 
 if __name__ == '__main__':
diff --git a/Lib/test/test_importlib/import_/util.py b/Lib/test/test_importlib/import_/util.py
deleted file mode 100644
index dcb490f967..0000000000
--- a/Lib/test/test_importlib/import_/util.py
+++ /dev/null
@@ -1,20 +0,0 @@
-from .. import util
-
-frozen_importlib, source_importlib = util.import_importlib('importlib')
-
-import builtins
-import functools
-import importlib
-import unittest
-
-
-__import__ = staticmethod(builtins.__import__), staticmethod(source_importlib.__import__)
-
-
-def mock_path_hook(*entries, importer):
-    """A mock sys.path_hooks entry."""
-    def hook(entry):
-        if entry not in entries:
-            raise ImportError
-        return importer
-    return hook
diff --git a/Lib/test/test_importlib/source/test_case_sensitivity.py b/Lib/test/test_importlib/source/test_case_sensitivity.py
index efd3146d90..29e95b2bbc 100644
--- a/Lib/test/test_importlib/source/test_case_sensitivity.py
+++ b/Lib/test/test_importlib/source/test_case_sensitivity.py
@@ -1,6 +1,5 @@
 """Test case-sensitivity (PEP 235)."""
 from .. import util
-from . import util as source_util
 
 importlib = util.import_importlib('importlib')
 machinery = util.import_importlib('importlib.machinery')
@@ -32,7 +31,7 @@ class CaseSensitivityTest:
         """Look for a module with matching and non-matching sensitivity."""
         sensitive_pkg = 'sensitive.{0}'.format(self.name)
         insensitive_pkg = 'insensitive.{0}'.format(self.name.lower())
-        context = source_util.create_modules(insensitive_pkg, sensitive_pkg)
+        context = util.create_modules(insensitive_pkg, sensitive_pkg)
         with context as mapping:
             sensitive_path = os.path.join(mapping['.root'], 'sensitive')
             insensitive_path = os.path.join(mapping['.root'], 'insensitive')
@@ -63,20 +62,28 @@ class CaseSensitivityTest:
             self.assertIsNotNone(insensitive)
             self.assertIn(self.name, insensitive.get_filename(self.name))
 
+
 class CaseSensitivityTestPEP302(CaseSensitivityTest):
     def find(self, finder):
         return finder.find_module(self.name)
 
-Frozen_CaseSensitivityTestPEP302, Source_CaseSensitivityTestPEP302 = util.test_both(
-    CaseSensitivityTestPEP302, importlib=importlib, machinery=machinery)
+
+(Frozen_CaseSensitivityTestPEP302,
+ Source_CaseSensitivityTestPEP302
+ ) = util.test_both(CaseSensitivityTestPEP302, importlib=importlib,
+                    machinery=machinery)
+
 
 class CaseSensitivityTestPEP451(CaseSensitivityTest):
     def find(self, finder):
         found = finder.find_spec(self.name)
         return found.loader if found is not None else found
 
-Frozen_CaseSensitivityTestPEP451, Source_CaseSensitivityTestPEP451 = util.test_both(
-    CaseSensitivityTestPEP451, importlib=importlib, machinery=machinery)
+
+(Frozen_CaseSensitivityTestPEP451,
+ Source_CaseSensitivityTestPEP451
+ ) = util.test_both(CaseSensitivityTestPEP451, importlib=importlib,
+                    machinery=machinery)
 
 
 if __name__ == '__main__':
diff --git a/Lib/test/test_importlib/source/test_file_loader.py b/Lib/test/test_importlib/source/test_file_loader.py
index 2d415f985d..73f4c62070 100644
--- a/Lib/test/test_importlib/source/test_file_loader.py
+++ b/Lib/test/test_importlib/source/test_file_loader.py
@@ -1,6 +1,5 @@
 from .. import abc
 from .. import util
-from . import util as source_util
 
 importlib = util.import_importlib('importlib')
 importlib_abc = util.import_importlib('importlib.abc')
@@ -71,7 +70,7 @@ class SimpleTest(abc.LoaderTests):
 
     # [basic]
     def test_module(self):
-        with source_util.create_modules('_temp') as mapping:
+        with util.create_modules('_temp') as mapping:
             loader = self.machinery.SourceFileLoader('_temp', mapping['_temp'])
             with warnings.catch_warnings():
                 warnings.simplefilter('ignore', DeprecationWarning)
@@ -83,7 +82,7 @@ class SimpleTest(abc.LoaderTests):
                 self.assertEqual(getattr(module, attr), value)
 
     def test_package(self):
-        with source_util.create_modules('_pkg.__init__') as mapping:
+        with util.create_modules('_pkg.__init__') as mapping:
             loader = self.machinery.SourceFileLoader('_pkg',
                                                  mapping['_pkg.__init__'])
             with warnings.catch_warnings():
@@ -98,7 +97,7 @@ class SimpleTest(abc.LoaderTests):
 
 
     def test_lacking_parent(self):
-        with source_util.create_modules('_pkg.__init__', '_pkg.mod')as mapping:
+        with util.create_modules('_pkg.__init__', '_pkg.mod')as mapping:
             loader = self.machinery.SourceFileLoader('_pkg.mod',
                                                     mapping['_pkg.mod'])
             with warnings.catch_warnings():
@@ -115,7 +114,7 @@ class SimpleTest(abc.LoaderTests):
         return lambda name: fxn(name) + 1
 
     def test_module_reuse(self):
-        with source_util.create_modules('_temp') as mapping:
+        with util.create_modules('_temp') as mapping:
             loader = self.machinery.SourceFileLoader('_temp', mapping['_temp'])
             with warnings.catch_warnings():
                 warnings.simplefilter('ignore', DeprecationWarning)
@@ -139,7 +138,7 @@ class SimpleTest(abc.LoaderTests):
         attributes = ('__file__', '__path__', '__package__')
         value = '<test>'
         name = '_temp'
-        with source_util.create_modules(name) as mapping:
+        with util.create_modules(name) as mapping:
             orig_module = types.ModuleType(name)
             for attr in attributes:
                 setattr(orig_module, attr, value)
@@ -159,7 +158,7 @@ class SimpleTest(abc.LoaderTests):
 
     # [syntax error]
     def test_bad_syntax(self):
-        with source_util.create_modules('_temp') as mapping:
+        with util.create_modules('_temp') as mapping:
             with open(mapping['_temp'], 'w') as file:
                 file.write('=')
             loader = self.machinery.SourceFileLoader('_temp', mapping['_temp'])
@@ -190,11 +189,11 @@ class SimpleTest(abc.LoaderTests):
             if os.path.exists(pycache):
                 shutil.rmtree(pycache)
 
-    @source_util.writes_bytecode_files
+    @util.writes_bytecode_files
     def test_timestamp_overflow(self):
         # When a modification timestamp is larger than 2**32, it should be
         # truncated rather than raise an OverflowError.
-        with source_util.create_modules('_temp') as mapping:
+        with util.create_modules('_temp') as mapping:
             source = mapping['_temp']
             compiled = self.util.cache_from_source(source)
             with open(source, 'w') as f:
@@ -236,9 +235,11 @@ class SimpleTest(abc.LoaderTests):
                 warnings.simplefilter('ignore', DeprecationWarning)
                 loader.load_module('bad name')
 
-Frozen_SimpleTest, Source_SimpleTest = util.test_both(
-        SimpleTest, importlib=importlib, machinery=machinery, abc=importlib_abc,
-        util=importlib_util)
+
+(Frozen_SimpleTest,
+ Source_SimpleTest
+ ) = util.test_both(SimpleTest, importlib=importlib, machinery=machinery,
+                    abc=importlib_abc, util=importlib_util)
 
 
 class BadBytecodeTest:
@@ -275,45 +276,45 @@ class BadBytecodeTest:
         return bytecode_path
 
     def _test_empty_file(self, test, *, del_source=False):
-        with source_util.create_modules('_temp') as mapping:
+        with util.create_modules('_temp') as mapping:
             bc_path = self.manipulate_bytecode('_temp', mapping,
                                                 lambda bc: b'',
                                                 del_source=del_source)
             test('_temp', mapping, bc_path)
 
-    @source_util.writes_bytecode_files
+    @util.writes_bytecode_files
     def _test_partial_magic(self, test, *, del_source=False):
         # When their are less than 4 bytes to a .pyc, regenerate it if
         # possible, else raise ImportError.
-        with source_util.create_modules('_temp') as mapping:
+        with util.create_modules('_temp') as mapping:
             bc_path = self.manipulate_bytecode('_temp', mapping,
                                                 lambda bc: bc[:3],
                                                 del_source=del_source)
             test('_temp', mapping, bc_path)
 
     def _test_magic_only(self, test, *, del_source=False):
-        with source_util.create_modules('_temp') as mapping:
+        with util.create_modules('_temp') as mapping:
             bc_path = self.manipulate_bytecode('_temp', mapping,
                                                 lambda bc: bc[:4],
                                                 del_source=del_source)
             test('_temp', mapping, bc_path)
 
     def _test_partial_timestamp(self, test, *, del_source=False):
-        with source_util.create_modules('_temp') as mapping:
+        with util.create_modules('_temp') as mapping:
             bc_path = self.manipulate_bytecode('_temp', mapping,
                                                 lambda bc: bc[:7],
                                                 del_source=del_source)
             test('_temp', mapping, bc_path)
 
     def _test_partial_size(self, test, *, del_source=False):
-        with source_util.create_modules('_temp') as mapping:
+        with util.create_modules('_temp') as mapping:
             bc_path = self.manipulate_bytecode('_temp', mapping,
                                                 lambda bc: bc[:11],
                                                 del_source=del_source)
             test('_temp', mapping, bc_path)
 
     def _test_no_marshal(self, *, del_source=False):
-        with source_util.create_modules('_temp') as mapping:
+        with util.create_modules('_temp') as mapping:
             bc_path = self.manipulate_bytecode('_temp', mapping,
                                                 lambda bc: bc[:12],
                                                 del_source=del_source)
@@ -322,7 +323,7 @@ class BadBytecodeTest:
                 self.import_(file_path, '_temp')
 
     def _test_non_code_marshal(self, *, del_source=False):
-        with source_util.create_modules('_temp') as mapping:
+        with util.create_modules('_temp') as mapping:
             bytecode_path = self.manipulate_bytecode('_temp', mapping,
                                     lambda bc: bc[:12] + marshal.dumps(b'abcd'),
                                     del_source=del_source)
@@ -333,7 +334,7 @@ class BadBytecodeTest:
             self.assertEqual(cm.exception.path, bytecode_path)
 
     def _test_bad_marshal(self, *, del_source=False):
-        with source_util.create_modules('_temp') as mapping:
+        with util.create_modules('_temp') as mapping:
             bytecode_path = self.manipulate_bytecode('_temp', mapping,
                                                 lambda bc: bc[:12] + b'<test>',
                                                 del_source=del_source)
@@ -342,11 +343,12 @@ class BadBytecodeTest:
                 self.import_(file_path, '_temp')
 
     def _test_bad_magic(self, test, *, del_source=False):
-        with source_util.create_modules('_temp') as mapping:
+        with util.create_modules('_temp') as mapping:
             bc_path = self.manipulate_bytecode('_temp', mapping,
                                     lambda bc: b'\x00\x00\x00\x00' + bc[4:])
             test('_temp', mapping, bc_path)
 
+
 class BadBytecodeTestPEP451(BadBytecodeTest):
 
     def import_(self, file, module_name):
@@ -355,6 +357,7 @@ class BadBytecodeTestPEP451(BadBytecodeTest):
         module.__spec__ = self.util.spec_from_loader(module_name, loader)
         loader.exec_module(module)
 
+
 class BadBytecodeTestPEP302(BadBytecodeTest):
 
     def import_(self, file, module_name):
@@ -371,7 +374,7 @@ class SourceLoaderBadBytecodeTest:
     def setUpClass(cls):
         cls.loader = cls.machinery.SourceFileLoader
 
-    @source_util.writes_bytecode_files
+    @util.writes_bytecode_files
     def test_empty_file(self):
         # When a .pyc is empty, regenerate it if possible, else raise
         # ImportError.
@@ -390,7 +393,7 @@ class SourceLoaderBadBytecodeTest:
 
         self._test_partial_magic(test)
 
-    @source_util.writes_bytecode_files
+    @util.writes_bytecode_files
     def test_magic_only(self):
         # When there is only the magic number, regenerate the .pyc if possible,
         # else raise EOFError.
@@ -401,7 +404,7 @@ class SourceLoaderBadBytecodeTest:
 
         self._test_magic_only(test)
 
-    @source_util.writes_bytecode_files
+    @util.writes_bytecode_files
     def test_bad_magic(self):
         # When the magic number is different, the bytecode should be
         # regenerated.
@@ -413,7 +416,7 @@ class SourceLoaderBadBytecodeTest:
 
         self._test_bad_magic(test)
 
-    @source_util.writes_bytecode_files
+    @util.writes_bytecode_files
     def test_partial_timestamp(self):
         # When the timestamp is partial, regenerate the .pyc, else
         # raise EOFError.
@@ -424,7 +427,7 @@ class SourceLoaderBadBytecodeTest:
 
         self._test_partial_timestamp(test)
 
-    @source_util.writes_bytecode_files
+    @util.writes_bytecode_files
     def test_partial_size(self):
         # When the size is partial, regenerate the .pyc, else
         # raise EOFError.
@@ -435,29 +438,29 @@ class SourceLoaderBadBytecodeTest:
 
         self._test_partial_size(test)
 
-    @source_util.writes_bytecode_files
+    @util.writes_bytecode_files
     def test_no_marshal(self):
         # When there is only the magic number and timestamp, raise EOFError.
         self._test_no_marshal()
 
-    @source_util.writes_bytecode_files
+    @util.writes_bytecode_files
     def test_non_code_marshal(self):
         self._test_non_code_marshal()
         # XXX ImportError when sourceless
 
     # [bad marshal]
-    @source_util.writes_bytecode_files
+    @util.writes_bytecode_files
     def test_bad_marshal(self):
         # Bad marshal data should raise a ValueError.
         self._test_bad_marshal()
 
     # [bad timestamp]
-    @source_util.writes_bytecode_files
+    @util.writes_bytecode_files
     def test_old_timestamp(self):
         # When the timestamp is older than the source, bytecode should be
         # regenerated.
         zeros = b'\x00\x00\x00\x00'
-        with source_util.create_modules('_temp') as mapping:
+        with util.create_modules('_temp') as mapping:
             py_compile.compile(mapping['_temp'])
             bytecode_path = self.util.cache_from_source(mapping['_temp'])
             with open(bytecode_path, 'r+b') as bytecode_file:
@@ -471,10 +474,10 @@ class SourceLoaderBadBytecodeTest:
                 self.assertEqual(bytecode_file.read(4), source_timestamp)
 
     # [bytecode read-only]
-    @source_util.writes_bytecode_files
+    @util.writes_bytecode_files
     def test_read_only_bytecode(self):
         # When bytecode is read-only but should be rewritten, fail silently.
-        with source_util.create_modules('_temp') as mapping:
+        with util.create_modules('_temp') as mapping:
             # Create bytecode that will need to be re-created.
             py_compile.compile(mapping['_temp'])
             bytecode_path = self.util.cache_from_source(mapping['_temp'])
@@ -491,21 +494,29 @@ class SourceLoaderBadBytecodeTest:
                 # Make writable for eventual clean-up.
                 os.chmod(bytecode_path, stat.S_IWUSR)
 
+
 class SourceLoaderBadBytecodeTestPEP451(
         SourceLoaderBadBytecodeTest, BadBytecodeTestPEP451):
     pass
 
-Frozen_SourceBadBytecodePEP451, Source_SourceBadBytecodePEP451 = util.test_both(
-        SourceLoaderBadBytecodeTestPEP451, importlib=importlib, machinery=machinery,
-        abc=importlib_abc, util=importlib_util)
+
+(Frozen_SourceBadBytecodePEP451,
+ Source_SourceBadBytecodePEP451
+ ) = util.test_both(SourceLoaderBadBytecodeTestPEP451, importlib=importlib,
+                    machinery=machinery, abc=importlib_abc,
+                    util=importlib_util)
+
 
 class SourceLoaderBadBytecodeTestPEP302(
         SourceLoaderBadBytecodeTest, BadBytecodeTestPEP302):
     pass
 
-Frozen_SourceBadBytecodePEP302, Source_SourceBadBytecodePEP302 = util.test_both(
-        SourceLoaderBadBytecodeTestPEP302, importlib=importlib, machinery=machinery,
-        abc=importlib_abc, util=importlib_util)
+
+(Frozen_SourceBadBytecodePEP302,
+ Source_SourceBadBytecodePEP302
+ ) = util.test_both(SourceLoaderBadBytecodeTestPEP302, importlib=importlib,
+                    machinery=machinery, abc=importlib_abc,
+                    util=importlib_util)
 
 
 class SourcelessLoaderBadBytecodeTest:
@@ -567,21 +578,29 @@ class SourcelessLoaderBadBytecodeTest:
     def test_non_code_marshal(self):
         self._test_non_code_marshal(del_source=True)
 
+
 class SourcelessLoaderBadBytecodeTestPEP451(SourcelessLoaderBadBytecodeTest,
         BadBytecodeTestPEP451):
     pass
 
-Frozen_SourcelessBadBytecodePEP451, Source_SourcelessBadBytecodePEP451 = util.test_both(
-        SourcelessLoaderBadBytecodeTestPEP451, importlib=importlib,
-        machinery=machinery, abc=importlib_abc, util=importlib_util)
+
+(Frozen_SourcelessBadBytecodePEP451,
+ Source_SourcelessBadBytecodePEP451
+ ) = util.test_both(SourcelessLoaderBadBytecodeTestPEP451, importlib=importlib,
+                    machinery=machinery, abc=importlib_abc,
+                    util=importlib_util)
+
 
 class SourcelessLoaderBadBytecodeTestPEP302(SourcelessLoaderBadBytecodeTest,
         BadBytecodeTestPEP302):
     pass
 
-Frozen_SourcelessBadBytecodePEP302, Source_SourcelessBadBytecodePEP302 = util.test_both(
-        SourcelessLoaderBadBytecodeTestPEP302, importlib=importlib,
-        machinery=machinery, abc=importlib_abc, util=importlib_util)
+
+(Frozen_SourcelessBadBytecodePEP302,
+ Source_SourcelessBadBytecodePEP302
+ ) = util.test_both(SourcelessLoaderBadBytecodeTestPEP302, importlib=importlib,
+                    machinery=machinery, abc=importlib_abc,
+                    util=importlib_util)
 
 
 if __name__ == '__main__':
diff --git a/Lib/test/test_importlib/source/test_finder.py b/Lib/test/test_importlib/source/test_finder.py
index 473297bdc8..f372b850dc 100644
--- a/Lib/test/test_importlib/source/test_finder.py
+++ b/Lib/test/test_importlib/source/test_finder.py
@@ -1,6 +1,5 @@
 from .. import abc
 from .. import util
-from . import util as source_util
 
 machinery = util.import_importlib('importlib.machinery')
 
@@ -60,7 +59,7 @@ class FinderTests(abc.FinderTests):
         """
         if create is None:
             create = {test}
-        with source_util.create_modules(*create) as mapping:
+        with util.create_modules(*create) as mapping:
             if compile_:
                 for name in compile_:
                     py_compile.compile(mapping[name])
@@ -100,14 +99,14 @@ class FinderTests(abc.FinderTests):
 
     # [sub module]
     def test_module_in_package(self):
-        with source_util.create_modules('pkg.__init__', 'pkg.sub') as mapping:
+        with util.create_modules('pkg.__init__', 'pkg.sub') as mapping:
             pkg_dir = os.path.dirname(mapping['pkg.__init__'])
             loader = self.import_(pkg_dir, 'pkg.sub')
             self.assertTrue(hasattr(loader, 'load_module'))
 
     # [sub package]
     def test_package_in_package(self):
-        context = source_util.create_modules('pkg.__init__', 'pkg.sub.__init__')
+        context = util.create_modules('pkg.__init__', 'pkg.sub.__init__')
         with context as mapping:
             pkg_dir = os.path.dirname(mapping['pkg.__init__'])
             loader = self.import_(pkg_dir, 'pkg.sub')
@@ -120,7 +119,7 @@ class FinderTests(abc.FinderTests):
         self.assertIn('__init__', loader.get_filename(name))
 
     def test_failure(self):
-        with source_util.create_modules('blah') as mapping:
+        with util.create_modules('blah') as mapping:
             nothing = self.import_(mapping['.root'], 'sdfsadsadf')
             self.assertIsNone(nothing)
 
@@ -147,7 +146,7 @@ class FinderTests(abc.FinderTests):
     # Regression test for http://bugs.python.org/issue14846
     def test_dir_removal_handling(self):
         mod = 'mod'
-        with source_util.create_modules(mod) as mapping:
+        with util.create_modules(mod) as mapping:
             finder = self.get_finder(mapping['.root'])
             found = self._find(finder, 'mod', loader_only=True)
             self.assertIsNotNone(found)
@@ -196,8 +195,10 @@ class FinderTestsPEP451(FinderTests):
         spec = finder.find_spec(name)
         return spec.loader if spec is not None else spec
 
-Frozen_FinderTestsPEP451, Source_FinderTestsPEP451 = util.test_both(
-        FinderTestsPEP451, machinery=machinery)
+
+(Frozen_FinderTestsPEP451,
+ Source_FinderTestsPEP451
+ ) = util.test_both(FinderTestsPEP451, machinery=machinery)
 
 
 class FinderTestsPEP420(FinderTests):
@@ -210,8 +211,10 @@ class FinderTestsPEP420(FinderTests):
             loader_portions = finder.find_loader(name)
             return loader_portions[0] if loader_only else loader_portions
 
-Frozen_FinderTestsPEP420, Source_FinderTestsPEP420 = util.test_both(
-        FinderTestsPEP420, machinery=machinery)
+
+(Frozen_FinderTestsPEP420,
+ Source_FinderTestsPEP420
+ ) = util.test_both(FinderTestsPEP420, machinery=machinery)
 
 
 class FinderTestsPEP302(FinderTests):
@@ -223,9 +226,10 @@ class FinderTestsPEP302(FinderTests):
             warnings.simplefilter("ignore", DeprecationWarning)
             return finder.find_module(name)
 
-Frozen_FinderTestsPEP302, Source_FinderTestsPEP302 = util.test_both(
-        FinderTestsPEP302, machinery=machinery)
 
+(Frozen_FinderTestsPEP302,
+ Source_FinderTestsPEP302
+ ) = util.test_both(FinderTestsPEP302, machinery=machinery)
 
 
 if __name__ == '__main__':
diff --git a/Lib/test/test_importlib/source/test_path_hook.py b/Lib/test/test_importlib/source/test_path_hook.py
index 92da77265b..e6a2415bda 100644
--- a/Lib/test/test_importlib/source/test_path_hook.py
+++ b/Lib/test/test_importlib/source/test_path_hook.py
@@ -1,5 +1,4 @@
 from .. import util
-from . import util as source_util
 
 machinery = util.import_importlib('importlib.machinery')
 
@@ -15,7 +14,7 @@ class PathHookTest:
             self.machinery.SOURCE_SUFFIXES))
 
     def test_success(self):
-        with source_util.create_modules('dummy') as mapping:
+        with util.create_modules('dummy') as mapping:
             self.assertTrue(hasattr(self.path_hook()(mapping['.root']),
                                  'find_module'))
 
@@ -23,7 +22,10 @@ class PathHookTest:
         # The empty string represents the cwd.
         self.assertTrue(hasattr(self.path_hook()(''), 'find_module'))
 
-Frozen_PathHookTest, Source_PathHooktest = util.test_both(PathHookTest, machinery=machinery)
+
+(Frozen_PathHookTest,
+ Source_PathHooktest
+ ) = util.test_both(PathHookTest, machinery=machinery)
 
 
 if __name__ == '__main__':
diff --git a/Lib/test/test_importlib/source/test_source_encoding.py b/Lib/test/test_importlib/source/test_source_encoding.py
index c62dfa108d..b604afb5ec 100644
--- a/Lib/test/test_importlib/source/test_source_encoding.py
+++ b/Lib/test/test_importlib/source/test_source_encoding.py
@@ -1,5 +1,4 @@
 from .. import util
-from . import util as source_util
 
 machinery = util.import_importlib('importlib.machinery')
 
@@ -37,7 +36,7 @@ class EncodingTest:
     module_name = '_temp'
 
     def run_test(self, source):
-        with source_util.create_modules(self.module_name) as mapping:
+        with util.create_modules(self.module_name) as mapping:
             with open(mapping[self.module_name], 'wb') as file:
                 file.write(source)
             loader = self.machinery.SourceFileLoader(self.module_name,
@@ -89,6 +88,7 @@ class EncodingTest:
         with self.assertRaises(SyntaxError):
             self.run_test(source)
 
+
 class EncodingTestPEP451(EncodingTest):
 
     def load(self, loader):
@@ -97,8 +97,11 @@ class EncodingTestPEP451(EncodingTest):
         loader.exec_module(module)
         return module
 
-Frozen_EncodingTestPEP451, Source_EncodingTestPEP451 = util.test_both(
-        EncodingTestPEP451, machinery=machinery)
+
+(Frozen_EncodingTestPEP451,
+ Source_EncodingTestPEP451
+ ) = util.test_both(EncodingTestPEP451, machinery=machinery)
+
 
 class EncodingTestPEP302(EncodingTest):
 
@@ -107,8 +110,10 @@ class EncodingTestPEP302(EncodingTest):
             warnings.simplefilter('ignore', DeprecationWarning)
             return loader.load_module(self.module_name)
 
-Frozen_EncodingTestPEP302, Source_EncodingTestPEP302 = util.test_both(
-        EncodingTestPEP302, machinery=machinery)
+
+(Frozen_EncodingTestPEP302,
+ Source_EncodingTestPEP302
+ ) = util.test_both(EncodingTestPEP302, machinery=machinery)
 
 
 class LineEndingTest:
@@ -120,7 +125,7 @@ class LineEndingTest:
         module_name = '_temp'
         source_lines = [b"a = 42", b"b = -13", b'']
         source = line_ending.join(source_lines)
-        with source_util.create_modules(module_name) as mapping:
+        with util.create_modules(module_name) as mapping:
             with open(mapping[module_name], 'wb') as file:
                 file.write(source)
             loader = self.machinery.SourceFileLoader(module_name,
@@ -139,6 +144,7 @@ class LineEndingTest:
     def test_lf(self):
         self.run_test(b'\n')
 
+
 class LineEndingTestPEP451(LineEndingTest):
 
     def load(self, loader, module_name):
@@ -147,8 +153,11 @@ class LineEndingTestPEP451(LineEndingTest):
         loader.exec_module(module)
         return module
 
-Frozen_LineEndingTestPEP451, Source_LineEndingTestPEP451 = util.test_both(
-        LineEndingTestPEP451, machinery=machinery)
+
+(Frozen_LineEndingTestPEP451,
+ Source_LineEndingTestPEP451
+ ) = util.test_both(LineEndingTestPEP451, machinery=machinery)
+
 
 class LineEndingTestPEP302(LineEndingTest):
 
@@ -157,8 +166,10 @@ class LineEndingTestPEP302(LineEndingTest):
             warnings.simplefilter('ignore', DeprecationWarning)
             return loader.load_module(module_name)
 
-Frozen_LineEndingTestPEP302, Source_LineEndingTestPEP302 = util.test_both(
-        LineEndingTestPEP302, machinery=machinery)
+
+(Frozen_LineEndingTestPEP302,
+ Source_LineEndingTestPEP302
+ ) = util.test_both(LineEndingTestPEP302, machinery=machinery)
 
 
 if __name__ == '__main__':
diff --git a/Lib/test/test_importlib/source/util.py b/Lib/test/test_importlib/source/util.py
deleted file mode 100644
index 63cd25adc4..0000000000
--- a/Lib/test/test_importlib/source/util.py
+++ /dev/null
@@ -1,96 +0,0 @@
-from .. import util
-import contextlib
-import errno
-import functools
-import os
-import os.path
-import sys
-import tempfile
-from test import support
-
-
-def writes_bytecode_files(fxn):
-    """Decorator to protect sys.dont_write_bytecode from mutation and to skip
-    tests that require it to be set to False."""
-    if sys.dont_write_bytecode:
-        return lambda *args, **kwargs: None
-    @functools.wraps(fxn)
-    def wrapper(*args, **kwargs):
-        original = sys.dont_write_bytecode
-        sys.dont_write_bytecode = False
-        try:
-            to_return = fxn(*args, **kwargs)
-        finally:
-            sys.dont_write_bytecode = original
-        return to_return
-    return wrapper
-
-
-def ensure_bytecode_path(bytecode_path):
-    """Ensure that the __pycache__ directory for PEP 3147 pyc file exists.
-
-    :param bytecode_path: File system path to PEP 3147 pyc file.
-    """
-    try:
-        os.mkdir(os.path.dirname(bytecode_path))
-    except OSError as error:
-        if error.errno != errno.EEXIST:
-            raise
-
-
-@contextlib.contextmanager
-def create_modules(*names):
-    """Temporarily create each named module with an attribute (named 'attr')
-    that contains the name passed into the context manager that caused the
-    creation of the module.
-
-    All files are created in a temporary directory returned by
-    tempfile.mkdtemp(). This directory is inserted at the beginning of
-    sys.path. When the context manager exits all created files (source and
-    bytecode) are explicitly deleted.
-
-    No magic is performed when creating packages! This means that if you create
-    a module within a package you must also create the package's __init__ as
-    well.
-
-    """
-    source = 'attr = {0!r}'
-    created_paths = []
-    mapping = {}
-    state_manager = None
-    uncache_manager = None
-    try:
-        temp_dir = tempfile.mkdtemp()
-        mapping['.root'] = temp_dir
-        import_names = set()
-        for name in names:
-            if not name.endswith('__init__'):
-                import_name = name
-            else:
-                import_name = name[:-len('.__init__')]
-            import_names.add(import_name)
-            if import_name in sys.modules:
-                del sys.modules[import_name]
-            name_parts = name.split('.')
-            file_path = temp_dir
-            for directory in name_parts[:-1]:
-                file_path = os.path.join(file_path, directory)
-                if not os.path.exists(file_path):
-                    os.mkdir(file_path)
-                    created_paths.append(file_path)
-            file_path = os.path.join(file_path, name_parts[-1] + '.py')
-            with open(file_path, 'w') as file:
-                file.write(source.format(name))
-            created_paths.append(file_path)
-            mapping[name] = file_path
-        uncache_manager = util.uncache(*import_names)
-        uncache_manager.__enter__()
-        state_manager = util.import_state(path=[temp_dir])
-        state_manager.__enter__()
-        yield mapping
-    finally:
-        if state_manager is not None:
-            state_manager.__exit__(None, None, None)
-        if uncache_manager is not None:
-            uncache_manager.__exit__(None, None, None)
-        support.rmtree(temp_dir)
diff --git a/Lib/test/test_importlib/test_abc.py b/Lib/test/test_importlib/test_abc.py
index a1f8e76302..d4bf9153e9 100644
--- a/Lib/test/test_importlib/test_abc.py
+++ b/Lib/test/test_importlib/test_abc.py
@@ -10,12 +10,13 @@ import unittest
 from unittest import mock
 import warnings
 
-from . import util
+from . import util as test_util
+
+init = test_util.import_importlib('importlib')
+abc = test_util.import_importlib('importlib.abc')
+machinery = test_util.import_importlib('importlib.machinery')
+util = test_util.import_importlib('importlib.util')
 
-frozen_init, source_init = util.import_importlib('importlib')
-frozen_abc, source_abc = util.import_importlib('importlib.abc')
-machinery = util.import_importlib('importlib.machinery')
-frozen_util, source_util = util.import_importlib('importlib.util')
 
 ##### Inheritance ##############################################################
 class InheritanceTests:
@@ -26,8 +27,7 @@ class InheritanceTests:
     subclasses = []
     superclasses = []
 
-    def __init__(self, *args, **kwargs):
-        super().__init__(*args, **kwargs)
+    def setUp(self):
         self.superclasses = [getattr(self.abc, class_name)
                              for class_name in self.superclass_names]
         if hasattr(self, 'subclass_names'):
@@ -36,11 +36,11 @@ class InheritanceTests:
             # checking across module boundaries (i.e. the _bootstrap in abc is
             # not the same as the one in machinery). That means stealing one of
             # the modules from the other to make sure the same instance is used.
-            self.subclasses = [getattr(self.abc.machinery, class_name)
-                                for class_name in self.subclass_names]
+            machinery = self.abc.machinery
+            self.subclasses = [getattr(machinery, class_name)
+                               for class_name in self.subclass_names]
         assert self.subclasses or self.superclasses, self.__class__
-        testing = self.__class__.__name__.partition('_')[2]
-        self.__test = getattr(self.abc, testing)
+        self.__test = getattr(self.abc, self._NAME)
 
     def test_subclasses(self):
         # Test that the expected subclasses inherit.
@@ -54,94 +54,97 @@ class InheritanceTests:
             self.assertTrue(issubclass(self.__test, superclass),
                "{0} is not a superclass of {1}".format(superclass, self.__test))
 
-def create_inheritance_tests(base_class):
-    def set_frozen(ns):
-        ns['abc'] = frozen_abc
-    def set_source(ns):
-        ns['abc'] = source_abc
-
-    classes = []
-    for prefix, ns_set in [('Frozen', set_frozen), ('Source', set_source)]:
-        classes.append(types.new_class('_'.join([prefix, base_class.__name__]),
-                                       (base_class, unittest.TestCase),
-                                       exec_body=ns_set))
-    return classes
-
 
 class MetaPathFinder(InheritanceTests):
     superclass_names = ['Finder']
     subclass_names = ['BuiltinImporter', 'FrozenImporter', 'PathFinder',
                       'WindowsRegistryFinder']
 
-tests = create_inheritance_tests(MetaPathFinder)
-Frozen_MetaPathFinderInheritanceTests, Source_MetaPathFinderInheritanceTests = tests
+
+(Frozen_MetaPathFinderInheritanceTests,
+ Source_MetaPathFinderInheritanceTests
+ ) = test_util.test_both(MetaPathFinder, abc=abc)
 
 
 class PathEntryFinder(InheritanceTests):
     superclass_names = ['Finder']
     subclass_names = ['FileFinder']
 
-tests = create_inheritance_tests(PathEntryFinder)
-Frozen_PathEntryFinderInheritanceTests, Source_PathEntryFinderInheritanceTests = tests
+
+(Frozen_PathEntryFinderInheritanceTests,
+ Source_PathEntryFinderInheritanceTests
+ ) = test_util.test_both(PathEntryFinder, abc=abc)
 
 
 class ResourceLoader(InheritanceTests):
     superclass_names = ['Loader']
 
-tests = create_inheritance_tests(ResourceLoader)
-Frozen_ResourceLoaderInheritanceTests, Source_ResourceLoaderInheritanceTests = tests
+
+(Frozen_ResourceLoaderInheritanceTests,
+ Source_ResourceLoaderInheritanceTests
+ ) = test_util.test_both(ResourceLoader, abc=abc)
 
 
 class InspectLoader(InheritanceTests):
     superclass_names = ['Loader']
     subclass_names = ['BuiltinImporter', 'FrozenImporter', 'ExtensionFileLoader']
 
-tests = create_inheritance_tests(InspectLoader)
-Frozen_InspectLoaderInheritanceTests, Source_InspectLoaderInheritanceTests = tests
+
+(Frozen_InspectLoaderInheritanceTests,
+ Source_InspectLoaderInheritanceTests
+ ) = test_util.test_both(InspectLoader, abc=abc)
 
 
 class ExecutionLoader(InheritanceTests):
     superclass_names = ['InspectLoader']
     subclass_names = ['ExtensionFileLoader']
 
-tests = create_inheritance_tests(ExecutionLoader)
-Frozen_ExecutionLoaderInheritanceTests, Source_ExecutionLoaderInheritanceTests = tests
+
+(Frozen_ExecutionLoaderInheritanceTests,
+ Source_ExecutionLoaderInheritanceTests
+ ) = test_util.test_both(ExecutionLoader, abc=abc)
 
 
 class FileLoader(InheritanceTests):
     superclass_names = ['ResourceLoader', 'ExecutionLoader']
     subclass_names = ['SourceFileLoader', 'SourcelessFileLoader']
 
-tests = create_inheritance_tests(FileLoader)
-Frozen_FileLoaderInheritanceTests, Source_FileLoaderInheritanceTests = tests
+
+(Frozen_FileLoaderInheritanceTests,
+ Source_FileLoaderInheritanceTests
+ ) = test_util.test_both(FileLoader, abc=abc)
 
 
 class SourceLoader(InheritanceTests):
     superclass_names = ['ResourceLoader', 'ExecutionLoader']
     subclass_names = ['SourceFileLoader']
 
-tests = create_inheritance_tests(SourceLoader)
-Frozen_SourceLoaderInheritanceTests, Source_SourceLoaderInheritanceTests = tests
+
+(Frozen_SourceLoaderInheritanceTests,
+ Source_SourceLoaderInheritanceTests
+ ) = test_util.test_both(SourceLoader, abc=abc)
+
 
 ##### Default return values ####################################################
-def make_abc_subclasses(base_class):
-    classes = []
-    for kind, abc in [('Frozen', frozen_abc), ('Source', source_abc)]:
-        name = '_'.join([kind, base_class.__name__])
-        base_classes = base_class, getattr(abc, base_class.__name__)
-        classes.append(types.new_class(name, base_classes))
-    return classes
-
-def make_return_value_tests(base_class, test_class):
-    frozen_class, source_class = make_abc_subclasses(base_class)
-    tests = []
-    for prefix, class_in_test in [('Frozen', frozen_class), ('Source', source_class)]:
-        def set_ns(ns):
-            ns['ins'] = class_in_test()
-        tests.append(types.new_class('_'.join([prefix, test_class.__name__]),
-                                     (test_class, unittest.TestCase),
-                                     exec_body=set_ns))
-    return tests
+
+def make_abc_subclasses(base_class, name=None, inst=False, **kwargs):
+    if name is None:
+        name = base_class.__name__
+    base = {kind: getattr(splitabc, name)
+            for kind, splitabc in abc.items()}
+    return {cls._KIND: cls() if inst else cls
+            for cls in test_util.split_frozen(base_class, base, **kwargs)}
+
+
+class ABCTestHarness:
+
+    @property
+    def ins(self):
+        # Lazily set ins on the class.
+        cls = self.SPLIT[self._KIND]
+        ins = cls()
+        self.__class__.ins = ins
+        return ins
 
 
 class MetaPathFinder:
@@ -149,10 +152,10 @@ class MetaPathFinder:
     def find_module(self, fullname, path):
         return super().find_module(fullname, path)
 
-Frozen_MPF, Source_MPF = make_abc_subclasses(MetaPathFinder)
 
+class MetaPathFinderDefaultsTests(ABCTestHarness):
 
-class MetaPathFinderDefaultsTests:
+    SPLIT = make_abc_subclasses(MetaPathFinder)
 
     def test_find_module(self):
         # Default should return None.
@@ -163,8 +166,9 @@ class MetaPathFinderDefaultsTests:
         self.ins.invalidate_caches()
 
 
-tests = make_return_value_tests(MetaPathFinder, MetaPathFinderDefaultsTests)
-Frozen_MPFDefaultTests, Source_MPFDefaultTests = tests
+(Frozen_MPFDefaultTests,
+ Source_MPFDefaultTests
+ ) = test_util.test_both(MetaPathFinderDefaultsTests)
 
 
 class PathEntryFinder:
@@ -172,10 +176,10 @@ class PathEntryFinder:
     def find_loader(self, fullname):
         return super().find_loader(fullname)
 
-Frozen_PEF, Source_PEF = make_abc_subclasses(PathEntryFinder)
 
+class PathEntryFinderDefaultsTests(ABCTestHarness):
 
-class PathEntryFinderDefaultsTests:
+    SPLIT = make_abc_subclasses(PathEntryFinder)
 
     def test_find_loader(self):
         self.assertEqual((None, []), self.ins.find_loader('something'))
@@ -188,8 +192,9 @@ class PathEntryFinderDefaultsTests:
         self.ins.invalidate_caches()
 
 
-tests = make_return_value_tests(PathEntryFinder, PathEntryFinderDefaultsTests)
-Frozen_PEFDefaultTests, Source_PEFDefaultTests = tests
+(Frozen_PEFDefaultTests,
+ Source_PEFDefaultTests
+ ) = test_util.test_both(PathEntryFinderDefaultsTests)
 
 
 class Loader:
@@ -198,10 +203,9 @@ class Loader:
         return super().load_module(fullname)
 
 
-Frozen_L, Source_L = make_abc_subclasses(Loader)
+class LoaderDefaultsTests(ABCTestHarness):
 
-
-class LoaderDefaultsTests:
+    SPLIT = make_abc_subclasses(Loader)
 
     def test_load_module(self):
         with self.assertRaises(ImportError):
@@ -217,8 +221,9 @@ class LoaderDefaultsTests:
         self.assertTrue(repr(mod))
 
 
-tests = make_return_value_tests(Loader, LoaderDefaultsTests)
-Frozen_LDefaultTests, SourceLDefaultTests = tests
+(Frozen_LDefaultTests,
+ SourceLDefaultTests
+ ) = test_util.test_both(LoaderDefaultsTests)
 
 
 class ResourceLoader(Loader):
@@ -227,18 +232,18 @@ class ResourceLoader(Loader):
         return super().get_data(path)
 
 
-Frozen_RL, Source_RL = make_abc_subclasses(ResourceLoader)
-
+class ResourceLoaderDefaultsTests(ABCTestHarness):
 
-class ResourceLoaderDefaultsTests:
+    SPLIT = make_abc_subclasses(ResourceLoader)
 
     def test_get_data(self):
         with self.assertRaises(IOError):
             self.ins.get_data('/some/path')
 
 
-tests = make_return_value_tests(ResourceLoader, ResourceLoaderDefaultsTests)
-Frozen_RLDefaultTests, Source_RLDefaultTests = tests
+(Frozen_RLDefaultTests,
+ Source_RLDefaultTests
+ ) = test_util.test_both(ResourceLoaderDefaultsTests)
 
 
 class InspectLoader(Loader):
@@ -250,10 +255,12 @@ class InspectLoader(Loader):
         return super().get_source(fullname)
 
 
-Frozen_IL, Source_IL = make_abc_subclasses(InspectLoader)
+SPLIT_IL = make_abc_subclasses(InspectLoader)
 
 
-class InspectLoaderDefaultsTests:
+class InspectLoaderDefaultsTests(ABCTestHarness):
+
+    SPLIT = SPLIT_IL
 
     def test_is_package(self):
         with self.assertRaises(ImportError):
@@ -264,8 +271,9 @@ class InspectLoaderDefaultsTests:
             self.ins.get_source('blah')
 
 
-tests = make_return_value_tests(InspectLoader, InspectLoaderDefaultsTests)
-Frozen_ILDefaultTests, Source_ILDefaultTests = tests
+(Frozen_ILDefaultTests,
+ Source_ILDefaultTests
+ ) = test_util.test_both(InspectLoaderDefaultsTests)
 
 
 class ExecutionLoader(InspectLoader):
@@ -273,21 +281,25 @@ class ExecutionLoader(InspectLoader):
     def get_filename(self, fullname):
         return super().get_filename(fullname)
 
-Frozen_EL, Source_EL = make_abc_subclasses(ExecutionLoader)
+
+SPLIT_EL = make_abc_subclasses(ExecutionLoader)
 
 
-class ExecutionLoaderDefaultsTests:
+class ExecutionLoaderDefaultsTests(ABCTestHarness):
+
+    SPLIT = SPLIT_EL
 
     def test_get_filename(self):
         with self.assertRaises(ImportError):
             self.ins.get_filename('blah')
 
 
-tests = make_return_value_tests(ExecutionLoader, InspectLoaderDefaultsTests)
-Frozen_ELDefaultTests, Source_ELDefaultsTests = tests
+(Frozen_ELDefaultTests,
+ Source_ELDefaultsTests
+ ) = test_util.test_both(InspectLoaderDefaultsTests)
 
-##### MetaPathFinder concrete methods ##########################################
 
+##### MetaPathFinder concrete methods ##########################################
 class MetaPathFinderFindModuleTests:
 
     @classmethod
@@ -317,13 +329,12 @@ class MetaPathFinderFindModuleTests:
         self.assertIs(found, spec.loader)
 
 
-Frozen_MPFFindModuleTests, Source_MPFFindModuleTests = util.test_both(
-        MetaPathFinderFindModuleTests,
-        abc=(frozen_abc, source_abc),
-        util=(frozen_util, source_util))
+(Frozen_MPFFindModuleTests,
+ Source_MPFFindModuleTests
+ ) = test_util.test_both(MetaPathFinderFindModuleTests, abc=abc, util=util)
 
-##### PathEntryFinder concrete methods #########################################
 
+##### PathEntryFinder concrete methods #########################################
 class PathEntryFinderFindLoaderTests:
 
     @classmethod
@@ -361,11 +372,10 @@ class PathEntryFinderFindLoaderTests:
         self.assertEqual(paths, found[1])
 
 
-Frozen_PEFFindLoaderTests, Source_PEFFindLoaderTests = util.test_both(
-        PathEntryFinderFindLoaderTests,
-        abc=(frozen_abc, source_abc),
-        machinery=machinery,
-        util=(frozen_util, source_util))
+(Frozen_PEFFindLoaderTests,
+ Source_PEFFindLoaderTests
+ ) = test_util.test_both(PathEntryFinderFindLoaderTests, abc=abc, util=util,
+                         machinery=machinery)
 
 
 ##### Loader concrete methods ##################################################
@@ -386,7 +396,7 @@ class LoaderLoadModuleTests:
     def test_fresh(self):
         loader = self.loader()
         name = 'blah'
-        with util.uncache(name):
+        with test_util.uncache(name):
             loader.load_module(name)
             module = loader.found
             self.assertIs(sys.modules[name], module)
@@ -404,7 +414,7 @@ class LoaderLoadModuleTests:
         module = types.ModuleType(name)
         module.__spec__ = self.util.spec_from_loader(name, loader)
         module.__loader__ = loader
-        with util.uncache(name):
+        with test_util.uncache(name):
             sys.modules[name] = module
             loader.load_module(name)
             found = loader.found
@@ -412,10 +422,9 @@ class LoaderLoadModuleTests:
             self.assertIs(module, sys.modules[name])
 
 
-Frozen_LoaderLoadModuleTests, Source_LoaderLoadModuleTests = util.test_both(
-        LoaderLoadModuleTests,
-        abc=(frozen_abc, source_abc),
-        util=(frozen_util, source_util))
+(Frozen_LoaderLoadModuleTests,
+ Source_LoaderLoadModuleTests
+ ) = test_util.test_both(LoaderLoadModuleTests, abc=abc, util=util)
 
 
 ##### InspectLoader concrete methods ###########################################
@@ -461,11 +470,10 @@ class InspectLoaderSourceToCodeTests:
         self.assertEqual(code.co_filename, '<string>')
 
 
-class Frozen_ILSourceToCodeTests(InspectLoaderSourceToCodeTests, unittest.TestCase):
-    InspectLoaderSubclass = Frozen_IL
-
-class Source_ILSourceToCodeTests(InspectLoaderSourceToCodeTests, unittest.TestCase):
-    InspectLoaderSubclass = Source_IL
+(Frozen_ILSourceToCodeTests,
+ Source_ILSourceToCodeTests
+ ) = test_util.test_both(InspectLoaderSourceToCodeTests,
+                         InspectLoaderSubclass=SPLIT_IL)
 
 
 class InspectLoaderGetCodeTests:
@@ -495,11 +503,10 @@ class InspectLoaderGetCodeTests:
             loader.get_code('blah')
 
 
-class Frozen_ILGetCodeTests(InspectLoaderGetCodeTests, unittest.TestCase):
-    InspectLoaderSubclass = Frozen_IL
-
-class Source_ILGetCodeTests(InspectLoaderGetCodeTests, unittest.TestCase):
-    InspectLoaderSubclass = Source_IL
+(Frozen_ILGetCodeTests,
+ Source_ILGetCodeTests
+ ) = test_util.test_both(InspectLoaderGetCodeTests,
+                         InspectLoaderSubclass=SPLIT_IL)
 
 
 class InspectLoaderLoadModuleTests:
@@ -543,11 +550,10 @@ class InspectLoaderLoadModuleTests:
             self.assertEqual(module, sys.modules[self.module_name])
 
 
-class Frozen_ILLoadModuleTests(InspectLoaderLoadModuleTests, unittest.TestCase):
-    InspectLoaderSubclass = Frozen_IL
-
-class Source_ILLoadModuleTests(InspectLoaderLoadModuleTests, unittest.TestCase):
-    InspectLoaderSubclass = Source_IL
+(Frozen_ILLoadModuleTests,
+ Source_ILLoadModuleTests
+ ) = test_util.test_both(InspectLoaderLoadModuleTests,
+                         InspectLoaderSubclass=SPLIT_IL)
 
 
 ##### ExecutionLoader concrete methods #########################################
@@ -608,15 +614,14 @@ class ExecutionLoaderGetCodeTests:
         self.assertEqual(module.attr, 42)
 
 
-class Frozen_ELGetCodeTests(ExecutionLoaderGetCodeTests, unittest.TestCase):
-    ExecutionLoaderSubclass = Frozen_EL
-
-class Source_ELGetCodeTests(ExecutionLoaderGetCodeTests, unittest.TestCase):
-    ExecutionLoaderSubclass = Source_EL
+(Frozen_ELGetCodeTests,
+ Source_ELGetCodeTests
+ ) = test_util.test_both(ExecutionLoaderGetCodeTests,
+                         ExecutionLoaderSubclass=SPLIT_EL)
 
 
 ##### SourceLoader concrete methods ############################################
-class SourceLoader:
+class SourceOnlyLoader:
 
     # Globals that should be defined for all modules.
     source = (b"_ = '::'.join([__name__, __file__, __cached__, __package__, "
@@ -637,10 +642,10 @@ class SourceLoader:
         return '<module>'
 
 
-Frozen_SourceOnlyL, Source_SourceOnlyL = make_abc_subclasses(SourceLoader)
+SPLIT_SOL = make_abc_subclasses(SourceOnlyLoader, 'SourceLoader')
 
 
-class SourceLoader(SourceLoader):
+class SourceLoader(SourceOnlyLoader):
 
     source_mtime = 1
 
@@ -677,11 +682,7 @@ class SourceLoader(SourceLoader):
         return path == self.bytecode_path
 
 
-Frozen_SL, Source_SL = make_abc_subclasses(SourceLoader)
-Frozen_SL.util = frozen_util
-Source_SL.util = source_util
-Frozen_SL.init = frozen_init
-Source_SL.init = source_init
+SPLIT_SL = make_abc_subclasses(SourceLoader, util=util, init=init)
 
 
 class SourceLoaderTestHarness:
@@ -765,7 +766,7 @@ class SourceOnlyLoaderTests(SourceLoaderTestHarness):
         # Loading a module should set __name__, __loader__, __package__,
         # __path__ (for packages), __file__, and __cached__.
         # The module should also be put into sys.modules.
-        with util.uncache(self.name):
+        with test_util.uncache(self.name):
             with warnings.catch_warnings():
                 warnings.simplefilter('ignore', DeprecationWarning)
                 module = self.loader.load_module(self.name)
@@ -778,7 +779,7 @@ class SourceOnlyLoaderTests(SourceLoaderTestHarness):
         # is a package.
         # Testing the values for a package are covered by test_load_module.
         self.setUp(is_package=False)
-        with util.uncache(self.name):
+        with test_util.uncache(self.name):
             with warnings.catch_warnings():
                 warnings.simplefilter('ignore', DeprecationWarning)
                 module = self.loader.load_module(self.name)
@@ -798,13 +799,10 @@ class SourceOnlyLoaderTests(SourceLoaderTestHarness):
         self.assertEqual(returned_source, source)
 
 
-class Frozen_SourceOnlyLTests(SourceOnlyLoaderTests, unittest.TestCase):
-    loader_mock = Frozen_SourceOnlyL
-    util = frozen_util
-
-class Source_SourceOnlyLTests(SourceOnlyLoaderTests, unittest.TestCase):
-    loader_mock = Source_SourceOnlyL
-    util = source_util
+(Frozen_SourceOnlyLoaderTests,
+ Source_SourceOnlyLoaderTests
+ ) = test_util.test_both(SourceOnlyLoaderTests, util=util,
+                         loader_mock=SPLIT_SOL)
 
 
 @unittest.skipIf(sys.dont_write_bytecode, "sys.dont_write_bytecode is true")
@@ -896,15 +894,10 @@ class SourceLoaderBytecodeTests(SourceLoaderTestHarness):
         self.verify_code(code_object)
 
 
-class Frozen_SLBytecodeTests(SourceLoaderBytecodeTests, unittest.TestCase):
-    loader_mock = Frozen_SL
-    init = frozen_init
-    util = frozen_util
-
-class SourceSLBytecodeTests(SourceLoaderBytecodeTests, unittest.TestCase):
-    loader_mock = Source_SL
-    init = source_init
-    util = source_util
+(Frozen_SLBytecodeTests,
+ SourceSLBytecodeTests
+ ) = test_util.test_both(SourceLoaderBytecodeTests, init=init, util=util,
+                         loader_mock=SPLIT_SL)
 
 
 class SourceLoaderGetSourceTests:
@@ -940,11 +933,10 @@ class SourceLoaderGetSourceTests:
         self.assertEqual(mock.get_source(name), expect)
 
 
-class Frozen_SourceOnlyLGetSourceTests(SourceLoaderGetSourceTests, unittest.TestCase):
-    SourceOnlyLoaderMock = Frozen_SourceOnlyL
-
-class Source_SourceOnlyLGetSourceTests(SourceLoaderGetSourceTests, unittest.TestCase):
-    SourceOnlyLoaderMock = Source_SourceOnlyL
+(Frozen_SourceOnlyLoaderGetSourceTests,
+ Source_SourceOnlyLoaderGetSourceTests
+ ) = test_util.test_both(SourceLoaderGetSourceTests,
+                         SourceOnlyLoaderMock=SPLIT_SOL)
 
 
 if __name__ == '__main__':
diff --git a/Lib/test/test_importlib/test_api.py b/Lib/test/test_importlib/test_api.py
index 2a2d42bbfe..6bc3c564a5 100644
--- a/Lib/test/test_importlib/test_api.py
+++ b/Lib/test/test_importlib/test_api.py
@@ -1,8 +1,8 @@
-from . import util
+from . import util as test_util
 
-frozen_init, source_init = util.import_importlib('importlib')
-frozen_util, source_util = util.import_importlib('importlib.util')
-frozen_machinery, source_machinery = util.import_importlib('importlib.machinery')
+init = test_util.import_importlib('importlib')
+util = test_util.import_importlib('importlib.util')
+machinery = test_util.import_importlib('importlib.machinery')
 
 import os.path
 import sys
@@ -18,8 +18,8 @@ class ImportModuleTests:
 
     def test_module_import(self):
         # Test importing a top-level module.
-        with util.mock_modules('top_level') as mock:
-            with util.import_state(meta_path=[mock]):
+        with test_util.mock_modules('top_level') as mock:
+            with test_util.import_state(meta_path=[mock]):
                 module = self.init.import_module('top_level')
                 self.assertEqual(module.__name__, 'top_level')
 
@@ -28,8 +28,8 @@ class ImportModuleTests:
         pkg_name = 'pkg'
         pkg_long_name = '{0}.__init__'.format(pkg_name)
         name = '{0}.mod'.format(pkg_name)
-        with util.mock_modules(pkg_long_name, name) as mock:
-            with util.import_state(meta_path=[mock]):
+        with test_util.mock_modules(pkg_long_name, name) as mock:
+            with test_util.import_state(meta_path=[mock]):
                 module = self.init.import_module(name)
                 self.assertEqual(module.__name__, name)
 
@@ -40,16 +40,16 @@ class ImportModuleTests:
         module_name = 'mod'
         absolute_name = '{0}.{1}'.format(pkg_name, module_name)
         relative_name = '.{0}'.format(module_name)
-        with util.mock_modules(pkg_long_name, absolute_name) as mock:
-            with util.import_state(meta_path=[mock]):
+        with test_util.mock_modules(pkg_long_name, absolute_name) as mock:
+            with test_util.import_state(meta_path=[mock]):
                 self.init.import_module(pkg_name)
                 module = self.init.import_module(relative_name, pkg_name)
                 self.assertEqual(module.__name__, absolute_name)
 
     def test_deep_relative_package_import(self):
         modules = ['a.__init__', 'a.b.__init__', 'a.c']
-        with util.mock_modules(*modules) as mock:
-            with util.import_state(meta_path=[mock]):
+        with test_util.mock_modules(*modules) as mock:
+            with test_util.import_state(meta_path=[mock]):
                 self.init.import_module('a')
                 self.init.import_module('a.b')
                 module = self.init.import_module('..c', 'a.b')
@@ -61,8 +61,8 @@ class ImportModuleTests:
         pkg_name = 'pkg'
         pkg_long_name = '{0}.__init__'.format(pkg_name)
         name = '{0}.mod'.format(pkg_name)
-        with util.mock_modules(pkg_long_name, name) as mock:
-            with util.import_state(meta_path=[mock]):
+        with test_util.mock_modules(pkg_long_name, name) as mock:
+            with test_util.import_state(meta_path=[mock]):
                 self.init.import_module(pkg_name)
                 module = self.init.import_module(name, pkg_name)
                 self.assertEqual(module.__name__, name)
@@ -86,16 +86,15 @@ class ImportModuleTests:
             b_load_count += 1
         code = {'a': load_a, 'a.b': load_b}
         modules = ['a.__init__', 'a.b']
-        with util.mock_modules(*modules, module_code=code) as mock:
-            with util.import_state(meta_path=[mock]):
+        with test_util.mock_modules(*modules, module_code=code) as mock:
+            with test_util.import_state(meta_path=[mock]):
                 self.init.import_module('a.b')
         self.assertEqual(b_load_count, 1)
 
-class Frozen_ImportModuleTests(ImportModuleTests, unittest.TestCase):
-    init = frozen_init
 
-class Source_ImportModuleTests(ImportModuleTests, unittest.TestCase):
-    init = source_init
+(Frozen_ImportModuleTests,
+ Source_ImportModuleTests
+ ) = test_util.test_both(ImportModuleTests, init=init)
 
 
 class FindLoaderTests:
@@ -107,7 +106,7 @@ class FindLoaderTests:
     def test_sys_modules(self):
         # If a module with __loader__ is in sys.modules, then return it.
         name = 'some_mod'
-        with util.uncache(name):
+        with test_util.uncache(name):
             module = types.ModuleType(name)
             loader = 'a loader!'
             module.__loader__ = loader
@@ -120,7 +119,7 @@ class FindLoaderTests:
     def test_sys_modules_loader_is_None(self):
         # If sys.modules[name].__loader__ is None, raise ValueError.
         name = 'some_mod'
-        with util.uncache(name):
+        with test_util.uncache(name):
             module = types.ModuleType(name)
             module.__loader__ = None
             sys.modules[name] = module
@@ -133,7 +132,7 @@ class FindLoaderTests:
         # Should raise ValueError
         # Issue #17099
         name = 'some_mod'
-        with util.uncache(name):
+        with test_util.uncache(name):
             module = types.ModuleType(name)
             try:
                 del module.__loader__
@@ -148,8 +147,8 @@ class FindLoaderTests:
     def test_success(self):
         # Return the loader found on sys.meta_path.
         name = 'some_mod'
-        with util.uncache(name):
-            with util.import_state(meta_path=[self.FakeMetaFinder]):
+        with test_util.uncache(name):
+            with test_util.import_state(meta_path=[self.FakeMetaFinder]):
                 with warnings.catch_warnings():
                     warnings.simplefilter('ignore', DeprecationWarning)
                     self.assertEqual((name, None), self.init.find_loader(name))
@@ -158,8 +157,8 @@ class FindLoaderTests:
         # Searching on a path should work.
         name = 'some_mod'
         path = 'path to some place'
-        with util.uncache(name):
-            with util.import_state(meta_path=[self.FakeMetaFinder]):
+        with test_util.uncache(name):
+            with test_util.import_state(meta_path=[self.FakeMetaFinder]):
                 with warnings.catch_warnings():
                     warnings.simplefilter('ignore', DeprecationWarning)
                     self.assertEqual((name, path),
@@ -171,11 +170,10 @@ class FindLoaderTests:
             warnings.simplefilter('ignore', DeprecationWarning)
             self.assertIsNone(self.init.find_loader('nevergoingtofindthismodule'))
 
-class Frozen_FindLoaderTests(FindLoaderTests, unittest.TestCase):
-    init = frozen_init
 
-class Source_FindLoaderTests(FindLoaderTests, unittest.TestCase):
-    init = source_init
+(Frozen_FindLoaderTests,
+ Source_FindLoaderTests
+ ) = test_util.test_both(FindLoaderTests, init=init)
 
 
 class ReloadTests:
@@ -195,10 +193,10 @@ class ReloadTests:
             module = type(sys)('top_level')
             module.spam = 3
             sys.modules['top_level'] = module
-        mock = util.mock_modules('top_level',
-                                 module_code={'top_level': code})
+        mock = test_util.mock_modules('top_level',
+                                      module_code={'top_level': code})
         with mock:
-            with util.import_state(meta_path=[mock]):
+            with test_util.import_state(meta_path=[mock]):
                 module = self.init.import_module('top_level')
                 reloaded = self.init.reload(module)
                 actual = sys.modules['top_level']
@@ -230,7 +228,7 @@ class ReloadTests:
     def test_reload_location_changed(self):
         name = 'spam'
         with support.temp_cwd(None) as cwd:
-            with util.uncache('spam'):
+            with test_util.uncache('spam'):
                 with support.DirsOnSysPath(cwd):
                     # Start as a plain module.
                     self.init.invalidate_caches()
@@ -281,7 +279,7 @@ class ReloadTests:
     def test_reload_namespace_changed(self):
         name = 'spam'
         with support.temp_cwd(None) as cwd:
-            with util.uncache('spam'):
+            with test_util.uncache('spam'):
                 with support.DirsOnSysPath(cwd):
                     # Start as a namespace package.
                     self.init.invalidate_caches()
@@ -338,20 +336,16 @@ class ReloadTests:
         # See #19851.
         name = 'spam'
         subname = 'ham'
-        with util.temp_module(name, pkg=True) as pkg_dir:
-            fullname, _ = util.submodule(name, subname, pkg_dir)
+        with test_util.temp_module(name, pkg=True) as pkg_dir:
+            fullname, _ = test_util.submodule(name, subname, pkg_dir)
             ham = self.init.import_module(fullname)
             reloaded = self.init.reload(ham)
             self.assertIs(reloaded, ham)
 
 
-class Frozen_ReloadTests(ReloadTests, unittest.TestCase):
-    init = frozen_init
-    util = frozen_util
-
-class Source_ReloadTests(ReloadTests, unittest.TestCase):
-    init = source_init
-    util = source_util
+(Frozen_ReloadTests,
+ Source_ReloadTests
+ ) = test_util.test_both(ReloadTests, init=init, util=util)
 
 
 class InvalidateCacheTests:
@@ -384,11 +378,10 @@ class InvalidateCacheTests:
         self.addCleanup(lambda: sys.path_importer_cache.__delitem__(key))
         self.init.invalidate_caches()  # Shouldn't trigger an exception.
 
-class Frozen_InvalidateCacheTests(InvalidateCacheTests, unittest.TestCase):
-    init = frozen_init
 
-class Source_InvalidateCacheTests(InvalidateCacheTests, unittest.TestCase):
-    init = source_init
+(Frozen_InvalidateCacheTests,
+ Source_InvalidateCacheTests
+ ) = test_util.test_both(InvalidateCacheTests, init=init)
 
 
 class FrozenImportlibTests(unittest.TestCase):
@@ -398,6 +391,7 @@ class FrozenImportlibTests(unittest.TestCase):
         # Can't do an isinstance() check since separate copies of importlib
         # may have been used for import, so just check the name is not for the
         # frozen loader.
+        source_init = init['Source']
         self.assertNotEqual(source_init.__loader__.__class__.__name__,
                             'FrozenImporter')
 
@@ -426,11 +420,10 @@ class StartupTests:
                     elif self.machinery.FrozenImporter.find_module(name):
                         self.assertIsNot(module.__spec__, None)
 
-class Frozen_StartupTests(StartupTests, unittest.TestCase):
-    machinery = frozen_machinery
 
-class Source_StartupTests(StartupTests, unittest.TestCase):
-    machinery = source_machinery
+(Frozen_StartupTests,
+ Source_StartupTests
+ ) = test_util.test_both(StartupTests, machinery=machinery)
 
 
 if __name__ == '__main__':
diff --git a/Lib/test/test_importlib/test_lazy.py b/Lib/test/test_importlib/test_lazy.py
new file mode 100644
index 0000000000..2e191bbf5c
--- /dev/null
+++ b/Lib/test/test_importlib/test_lazy.py
@@ -0,0 +1,132 @@
+import importlib
+from importlib import abc
+from importlib import util
+import unittest
+
+from . import util as test_util
+
+
+class CollectInit:
+
+    def __init__(self, *args, **kwargs):
+        self.args = args
+        self.kwargs = kwargs
+
+    def exec_module(self, module):
+        return self
+
+
+class LazyLoaderFactoryTests(unittest.TestCase):
+
+    def test_init(self):
+        factory = util.LazyLoader.factory(CollectInit)
+        # E.g. what importlib.machinery.FileFinder instantiates loaders with
+        # plus keyword arguments.
+        lazy_loader = factory('module name', 'module path', kw='kw')
+        loader = lazy_loader.loader
+        self.assertEqual(('module name', 'module path'), loader.args)
+        self.assertEqual({'kw': 'kw'}, loader.kwargs)
+
+    def test_validation(self):
+        # No exec_module(), no lazy loading.
+        with self.assertRaises(TypeError):
+            util.LazyLoader.factory(object)
+
+
+class TestingImporter(abc.MetaPathFinder, abc.Loader):
+
+    module_name = 'lazy_loader_test'
+    mutated_name = 'changed'
+    loaded = None
+    source_code = 'attr = 42; __name__ = {!r}'.format(mutated_name)
+
+    def find_spec(self, name, path, target=None):
+        if name != self.module_name:
+            return None
+        return util.spec_from_loader(name, util.LazyLoader(self))
+
+    def exec_module(self, module):
+        exec(self.source_code, module.__dict__)
+        self.loaded = module
+
+
+class LazyLoaderTests(unittest.TestCase):
+
+    def test_init(self):
+        with self.assertRaises(TypeError):
+            util.LazyLoader(object)
+
+    def new_module(self, source_code=None):
+        loader = TestingImporter()
+        if source_code is not None:
+            loader.source_code = source_code
+        spec = util.spec_from_loader(TestingImporter.module_name,
+                                     util.LazyLoader(loader))
+        module = spec.loader.create_module(spec)
+        module.__spec__ = spec
+        module.__loader__ = spec.loader
+        spec.loader.exec_module(module)
+        # Module is now lazy.
+        self.assertIsNone(loader.loaded)
+        return module
+
+    def test_e2e(self):
+        # End-to-end test to verify the load is in fact lazy.
+        importer = TestingImporter()
+        assert importer.loaded is None
+        with test_util.uncache(importer.module_name):
+            with test_util.import_state(meta_path=[importer]):
+                module = importlib.import_module(importer.module_name)
+        self.assertIsNone(importer.loaded)
+        # Trigger load.
+        self.assertEqual(module.__loader__, importer)
+        self.assertIsNotNone(importer.loaded)
+        self.assertEqual(module, importer.loaded)
+
+    def test_attr_unchanged(self):
+        # An attribute only mutated as a side-effect of import should not be
+        # changed needlessly.
+        module = self.new_module()
+        self.assertEqual(TestingImporter.mutated_name, module.__name__)
+
+    def test_new_attr(self):
+        # A new attribute should persist.
+        module = self.new_module()
+        module.new_attr = 42
+        self.assertEqual(42, module.new_attr)
+
+    def test_mutated_preexisting_attr(self):
+        # Changing an attribute that already existed on the module --
+        # e.g. __name__ -- should persist.
+        module = self.new_module()
+        module.__name__ = 'bogus'
+        self.assertEqual('bogus', module.__name__)
+
+    def test_mutated_attr(self):
+        # Changing an attribute that comes into existence after an import
+        # should persist.
+        module = self.new_module()
+        module.attr = 6
+        self.assertEqual(6, module.attr)
+
+    def test_delete_eventual_attr(self):
+        # Deleting an attribute should stay deleted.
+        module = self.new_module()
+        del module.attr
+        self.assertFalse(hasattr(module, 'attr'))
+
+    def test_delete_preexisting_attr(self):
+        module = self.new_module()
+        del module.__name__
+        self.assertFalse(hasattr(module, '__name__'))
+
+    def test_module_substitution_error(self):
+        source_code = 'import sys; sys.modules[__name__] = 42'
+        module = self.new_module(source_code)
+        with test_util.uncache(TestingImporter.module_name):
+            with self.assertRaises(ValueError):
+                module.__name__
+
+
+if __name__ == '__main__':
+    unittest.main()
diff --git a/Lib/test/test_importlib/test_locks.py b/Lib/test/test_importlib/test_locks.py
index dc97ba1567..df0af12d38 100644
--- a/Lib/test/test_importlib/test_locks.py
+++ b/Lib/test/test_importlib/test_locks.py
@@ -1,7 +1,6 @@
-from . import util
-frozen_init, source_init = util.import_importlib('importlib')
-frozen_bootstrap = frozen_init._bootstrap
-source_bootstrap = source_init._bootstrap
+from . import util as test_util
+
+init = test_util.import_importlib('importlib')
 
 import sys
 import time
@@ -32,14 +31,20 @@ if threading is not None:
         test_timeout = None
         # _release_save() unsupported
         test_release_save_unacquired = None
+        # lock status in repr unsupported
+        test_repr = None
+        test_locked_repr = None
 
-    class Frozen_ModuleLockAsRLockTests(ModuleLockAsRLockTests, lock_tests.RLockTests):
-        LockType = frozen_bootstrap._ModuleLock
-
-    class Source_ModuleLockAsRLockTests(ModuleLockAsRLockTests, lock_tests.RLockTests):
-        LockType = source_bootstrap._ModuleLock
+    LOCK_TYPES = {kind: splitinit._bootstrap._ModuleLock
+                  for kind, splitinit in init.items()}
 
+    (Frozen_ModuleLockAsRLockTests,
+     Source_ModuleLockAsRLockTests
+     ) = test_util.test_both(ModuleLockAsRLockTests, lock_tests.RLockTests,
+                             LockType=LOCK_TYPES)
 else:
+    LOCK_TYPES = {}
+
     class Frozen_ModuleLockAsRLockTests(unittest.TestCase):
         pass
 
@@ -47,78 +52,94 @@ else:
         pass
 
 
-class DeadlockAvoidanceTests:
-
-    def setUp(self):
-        try:
-            self.old_switchinterval = sys.getswitchinterval()
-            sys.setswitchinterval(0.000001)
-        except AttributeError:
-            self.old_switchinterval = None
-
-    def tearDown(self):
-        if self.old_switchinterval is not None:
-            sys.setswitchinterval(self.old_switchinterval)
-
-    def run_deadlock_avoidance_test(self, create_deadlock):
-        NLOCKS = 10
-        locks = [self.LockType(str(i)) for i in range(NLOCKS)]
-        pairs = [(locks[i], locks[(i+1)%NLOCKS]) for i in range(NLOCKS)]
-        if create_deadlock:
-            NTHREADS = NLOCKS
-        else:
-            NTHREADS = NLOCKS - 1
-        barrier = threading.Barrier(NTHREADS)
-        results = []
-        def _acquire(lock):
-            """Try to acquire the lock. Return True on success, False on deadlock."""
+if threading is not None:
+    class DeadlockAvoidanceTests:
+
+        def setUp(self):
             try:
-                lock.acquire()
-            except self.DeadlockError:
-                return False
+                self.old_switchinterval = sys.getswitchinterval()
+                sys.setswitchinterval(0.000001)
+            except AttributeError:
+                self.old_switchinterval = None
+
+        def tearDown(self):
+            if self.old_switchinterval is not None:
+                sys.setswitchinterval(self.old_switchinterval)
+
+        def run_deadlock_avoidance_test(self, create_deadlock):
+            NLOCKS = 10
+            locks = [self.LockType(str(i)) for i in range(NLOCKS)]
+            pairs = [(locks[i], locks[(i+1)%NLOCKS]) for i in range(NLOCKS)]
+            if create_deadlock:
+                NTHREADS = NLOCKS
             else:
-                return True
-        def f():
-            a, b = pairs.pop()
-            ra = _acquire(a)
-            barrier.wait()
-            rb = _acquire(b)
-            results.append((ra, rb))
-            if rb:
-                b.release()
-            if ra:
-                a.release()
-        lock_tests.Bunch(f, NTHREADS).wait_for_finished()
-        self.assertEqual(len(results), NTHREADS)
-        return results
-
-    def test_deadlock(self):
-        results = self.run_deadlock_avoidance_test(True)
-        # At least one of the threads detected a potential deadlock on its
-        # second acquire() call.  It may be several of them, because the
-        # deadlock avoidance mechanism is conservative.
-        nb_deadlocks = results.count((True, False))
-        self.assertGreaterEqual(nb_deadlocks, 1)
-        self.assertEqual(results.count((True, True)), len(results) - nb_deadlocks)
-
-    def test_no_deadlock(self):
-        results = self.run_deadlock_avoidance_test(False)
-        self.assertEqual(results.count((True, False)), 0)
-        self.assertEqual(results.count((True, True)), len(results))
-
-@unittest.skipUnless(threading, "threads needed for this test")
-class Frozen_DeadlockAvoidanceTests(DeadlockAvoidanceTests, unittest.TestCase):
-    LockType = frozen_bootstrap._ModuleLock
-    DeadlockError = frozen_bootstrap._DeadlockError
-
-@unittest.skipUnless(threading, "threads needed for this test")
-class Source_DeadlockAvoidanceTests(DeadlockAvoidanceTests, unittest.TestCase):
-    LockType = source_bootstrap._ModuleLock
-    DeadlockError = source_bootstrap._DeadlockError
+                NTHREADS = NLOCKS - 1
+            barrier = threading.Barrier(NTHREADS)
+            results = []
+
+            def _acquire(lock):
+                """Try to acquire the lock. Return True on success,
+                False on deadlock."""
+                try:
+                    lock.acquire()
+                except self.DeadlockError:
+                    return False
+                else:
+                    return True
+
+            def f():
+                a, b = pairs.pop()
+                ra = _acquire(a)
+                barrier.wait()
+                rb = _acquire(b)
+                results.append((ra, rb))
+                if rb:
+                    b.release()
+                if ra:
+                    a.release()
+            lock_tests.Bunch(f, NTHREADS).wait_for_finished()
+            self.assertEqual(len(results), NTHREADS)
+            return results
+
+        def test_deadlock(self):
+            results = self.run_deadlock_avoidance_test(True)
+            # At least one of the threads detected a potential deadlock on its
+            # second acquire() call.  It may be several of them, because the
+            # deadlock avoidance mechanism is conservative.
+            nb_deadlocks = results.count((True, False))
+            self.assertGreaterEqual(nb_deadlocks, 1)
+            self.assertEqual(results.count((True, True)), len(results) - nb_deadlocks)
+
+        def test_no_deadlock(self):
+            results = self.run_deadlock_avoidance_test(False)
+            self.assertEqual(results.count((True, False)), 0)
+            self.assertEqual(results.count((True, True)), len(results))
+
+
+    DEADLOCK_ERRORS = {kind: splitinit._bootstrap._DeadlockError
+                       for kind, splitinit in init.items()}
+
+    (Frozen_DeadlockAvoidanceTests,
+     Source_DeadlockAvoidanceTests
+     ) = test_util.test_both(DeadlockAvoidanceTests,
+                             LockType=LOCK_TYPES,
+                             DeadlockError=DEADLOCK_ERRORS)
+else:
+    DEADLOCK_ERRORS = {}
+
+    class Frozen_DeadlockAvoidanceTests(unittest.TestCase):
+        pass
+
+    class Source_DeadlockAvoidanceTests(unittest.TestCase):
+        pass
 
 
 class LifetimeTests:
 
+    @property
+    def bootstrap(self):
+        return self.init._bootstrap
+
     def test_lock_lifetime(self):
         name = "xyzzy"
         self.assertNotIn(name, self.bootstrap._module_locks)
@@ -135,11 +156,10 @@ class LifetimeTests:
         self.assertEqual(0, len(self.bootstrap._module_locks),
                          self.bootstrap._module_locks)
 
-class Frozen_LifetimeTests(LifetimeTests, unittest.TestCase):
-    bootstrap = frozen_bootstrap
 
-class Source_LifetimeTests(LifetimeTests, unittest.TestCase):
-    bootstrap = source_bootstrap
+(Frozen_LifetimeTests,
+ Source_LifetimeTests
+ ) = test_util.test_both(LifetimeTests, init=init)
 
 
 @support.reap_threads
diff --git a/Lib/test/test_importlib/test_spec.py b/Lib/test/test_importlib/test_spec.py
index 71541f692e..8b333e8c2f 100644
--- a/Lib/test/test_importlib/test_spec.py
+++ b/Lib/test/test_importlib/test_spec.py
@@ -1,10 +1,8 @@
-from . import util
+from . import util as test_util
 
-frozen_init, source_init = util.import_importlib('importlib')
-frozen_bootstrap = frozen_init._bootstrap
-source_bootstrap = source_init._bootstrap
-frozen_machinery, source_machinery = util.import_importlib('importlib.machinery')
-frozen_util, source_util = util.import_importlib('importlib.util')
+init = test_util.import_importlib('importlib')
+machinery = test_util.import_importlib('importlib.machinery')
+util = test_util.import_importlib('importlib.util')
 
 import os.path
 from test.support import CleanImport
@@ -36,6 +34,9 @@ class TestLoader:
     def _is_package(self, name):
         return self.package
 
+    def create_module(self, spec):
+        return None
+
 
 class NewLoader(TestLoader):
 
@@ -52,6 +53,8 @@ class LegacyLoader(TestLoader):
     with warnings.catch_warnings():
         warnings.simplefilter("ignore", DeprecationWarning)
 
+        frozen_util = util['Frozen']
+
         @frozen_util.module_for_loader
         def load_module(self, module):
             module.ham = self.HAM
@@ -221,18 +224,17 @@ class ModuleSpecTests:
         self.assertEqual(self.loc_spec.cached, 'spam.pyc')
 
 
-class Frozen_ModuleSpecTests(ModuleSpecTests, unittest.TestCase):
-    util = frozen_util
-    machinery = frozen_machinery
-
-
-class Source_ModuleSpecTests(ModuleSpecTests, unittest.TestCase):
-    util = source_util
-    machinery = source_machinery
+(Frozen_ModuleSpecTests,
+ Source_ModuleSpecTests
+ ) = test_util.test_both(ModuleSpecTests, util=util, machinery=machinery)
 
 
 class ModuleSpecMethodsTests:
 
+    @property
+    def bootstrap(self):
+        return self.init._bootstrap
+
     def setUp(self):
         self.name = 'spam'
         self.path = 'spam.py'
@@ -243,152 +245,14 @@ class ModuleSpecMethodsTests:
                                                   origin=self.path)
         self.loc_spec._set_fileattr = True
 
-    # init_module_attrs
-
-    def test_init_module_attrs(self):
-        module = type(sys)(self.name)
-        spec = self.machinery.ModuleSpec(self.name, self.loader)
-        self.bootstrap._SpecMethods(spec).init_module_attrs(module)
-
-        self.assertEqual(module.__name__, spec.name)
-        self.assertIs(module.__loader__, spec.loader)
-        self.assertEqual(module.__package__, spec.parent)
-        self.assertIs(module.__spec__, spec)
-        self.assertFalse(hasattr(module, '__path__'))
-        self.assertFalse(hasattr(module, '__file__'))
-        self.assertFalse(hasattr(module, '__cached__'))
-
-    def test_init_module_attrs_package(self):
-        module = type(sys)(self.name)
-        spec = self.machinery.ModuleSpec(self.name, self.loader)
-        spec.submodule_search_locations = ['spam', 'ham']
-        self.bootstrap._SpecMethods(spec).init_module_attrs(module)
-
-        self.assertEqual(module.__name__, spec.name)
-        self.assertIs(module.__loader__, spec.loader)
-        self.assertEqual(module.__package__, spec.parent)
-        self.assertIs(module.__spec__, spec)
-        self.assertIs(module.__path__, spec.submodule_search_locations)
-        self.assertFalse(hasattr(module, '__file__'))
-        self.assertFalse(hasattr(module, '__cached__'))
-
-    def test_init_module_attrs_location(self):
-        module = type(sys)(self.name)
-        spec = self.loc_spec
-        self.bootstrap._SpecMethods(spec).init_module_attrs(module)
-
-        self.assertEqual(module.__name__, spec.name)
-        self.assertIs(module.__loader__, spec.loader)
-        self.assertEqual(module.__package__, spec.parent)
-        self.assertIs(module.__spec__, spec)
-        self.assertFalse(hasattr(module, '__path__'))
-        self.assertEqual(module.__file__, spec.origin)
-        self.assertEqual(module.__cached__,
-                         self.util.cache_from_source(spec.origin))
-
-    def test_init_module_attrs_different_name(self):
-        module = type(sys)('eggs')
-        spec = self.machinery.ModuleSpec(self.name, self.loader)
-        self.bootstrap._SpecMethods(spec).init_module_attrs(module)
-
-        self.assertEqual(module.__name__, spec.name)
-
-    def test_init_module_attrs_different_spec(self):
-        module = type(sys)(self.name)
-        module.__spec__ = self.machinery.ModuleSpec('eggs', object())
-        spec = self.machinery.ModuleSpec(self.name, self.loader)
-        self.bootstrap._SpecMethods(spec).init_module_attrs(module)
-
-        self.assertEqual(module.__name__, spec.name)
-        self.assertIs(module.__loader__, spec.loader)
-        self.assertEqual(module.__package__, spec.parent)
-        self.assertIs(module.__spec__, spec)
-
-    def test_init_module_attrs_already_set(self):
-        module = type(sys)('ham.eggs')
-        module.__loader__ = object()
-        module.__package__ = 'ham'
-        module.__path__ = ['eggs']
-        module.__file__ = 'ham/eggs/__init__.py'
-        module.__cached__ = self.util.cache_from_source(module.__file__)
-        original = vars(module).copy()
-        spec = self.loc_spec
-        spec.submodule_search_locations = ['']
-        self.bootstrap._SpecMethods(spec).init_module_attrs(module)
-
-        self.assertIs(module.__loader__, original['__loader__'])
-        self.assertEqual(module.__package__, original['__package__'])
-        self.assertIs(module.__path__, original['__path__'])
-        self.assertEqual(module.__file__, original['__file__'])
-        self.assertEqual(module.__cached__, original['__cached__'])
-
-    def test_init_module_attrs_immutable(self):
-        module = object()
-        spec = self.loc_spec
-        spec.submodule_search_locations = ['']
-        self.bootstrap._SpecMethods(spec).init_module_attrs(module)
-
-        self.assertFalse(hasattr(module, '__name__'))
-        self.assertFalse(hasattr(module, '__loader__'))
-        self.assertFalse(hasattr(module, '__package__'))
-        self.assertFalse(hasattr(module, '__spec__'))
-        self.assertFalse(hasattr(module, '__path__'))
-        self.assertFalse(hasattr(module, '__file__'))
-        self.assertFalse(hasattr(module, '__cached__'))
-
-    # create()
-
-    def test_create(self):
-        created = self.bootstrap._SpecMethods(self.spec).create()
-
-        self.assertEqual(created.__name__, self.spec.name)
-        self.assertIs(created.__loader__, self.spec.loader)
-        self.assertEqual(created.__package__, self.spec.parent)
-        self.assertIs(created.__spec__, self.spec)
-        self.assertFalse(hasattr(created, '__path__'))
-        self.assertFalse(hasattr(created, '__file__'))
-        self.assertFalse(hasattr(created, '__cached__'))
-
-    def test_create_from_loader(self):
-        module = type(sys.implementation)()
-        class CreatingLoader(TestLoader):
-            def create_module(self, spec):
-                return module
-        self.spec.loader = CreatingLoader()
-        created = self.bootstrap._SpecMethods(self.spec).create()
-
-        self.assertIs(created, module)
-        self.assertEqual(created.__name__, self.spec.name)
-        self.assertIs(created.__loader__, self.spec.loader)
-        self.assertEqual(created.__package__, self.spec.parent)
-        self.assertIs(created.__spec__, self.spec)
-        self.assertFalse(hasattr(created, '__path__'))
-        self.assertFalse(hasattr(created, '__file__'))
-        self.assertFalse(hasattr(created, '__cached__'))
-
-    def test_create_from_loader_not_handled(self):
-        class CreatingLoader(TestLoader):
-            def create_module(self, spec):
-                return None
-        self.spec.loader = CreatingLoader()
-        created = self.bootstrap._SpecMethods(self.spec).create()
-
-        self.assertEqual(created.__name__, self.spec.name)
-        self.assertIs(created.__loader__, self.spec.loader)
-        self.assertEqual(created.__package__, self.spec.parent)
-        self.assertIs(created.__spec__, self.spec)
-        self.assertFalse(hasattr(created, '__path__'))
-        self.assertFalse(hasattr(created, '__file__'))
-        self.assertFalse(hasattr(created, '__cached__'))
-
     # exec()
 
     def test_exec(self):
         self.spec.loader = NewLoader()
-        module = self.bootstrap._SpecMethods(self.spec).create()
+        module = self.util.module_from_spec(self.spec)
         sys.modules[self.name] = module
         self.assertFalse(hasattr(module, 'eggs'))
-        self.bootstrap._SpecMethods(self.spec).exec(module)
+        self.bootstrap._exec(self.spec, module)
 
         self.assertEqual(module.eggs, 1)
 
@@ -397,7 +261,7 @@ class ModuleSpecMethodsTests:
     def test_load(self):
         self.spec.loader = NewLoader()
         with CleanImport(self.spec.name):
-            loaded = self.bootstrap._SpecMethods(self.spec).load()
+            loaded = self.bootstrap._load(self.spec)
             installed = sys.modules[self.spec.name]
 
         self.assertEqual(loaded.eggs, 1)
@@ -410,7 +274,7 @@ class ModuleSpecMethodsTests:
                 sys.modules[module.__name__] = replacement
         self.spec.loader = ReplacingLoader()
         with CleanImport(self.spec.name):
-            loaded = self.bootstrap._SpecMethods(self.spec).load()
+            loaded = self.bootstrap._load(self.spec)
             installed = sys.modules[self.spec.name]
 
         self.assertIs(loaded, replacement)
@@ -423,7 +287,7 @@ class ModuleSpecMethodsTests:
         self.spec.loader = FailedLoader()
         with CleanImport(self.spec.name):
             with self.assertRaises(RuntimeError):
-                loaded = self.bootstrap._SpecMethods(self.spec).load()
+                loaded = self.bootstrap._load(self.spec)
             self.assertNotIn(self.spec.name, sys.modules)
 
     def test_load_failed_removed(self):
@@ -434,20 +298,20 @@ class ModuleSpecMethodsTests:
         self.spec.loader = FailedLoader()
         with CleanImport(self.spec.name):
             with self.assertRaises(RuntimeError):
-                loaded = self.bootstrap._SpecMethods(self.spec).load()
+                loaded = self.bootstrap._load(self.spec)
             self.assertNotIn(self.spec.name, sys.modules)
 
     def test_load_legacy(self):
         self.spec.loader = LegacyLoader()
         with CleanImport(self.spec.name):
-            loaded = self.bootstrap._SpecMethods(self.spec).load()
+            loaded = self.bootstrap._load(self.spec)
 
         self.assertEqual(loaded.ham, -1)
 
     def test_load_legacy_attributes(self):
         self.spec.loader = LegacyLoader()
         with CleanImport(self.spec.name):
-            loaded = self.bootstrap._SpecMethods(self.spec).load()
+            loaded = self.bootstrap._load(self.spec)
 
         self.assertIs(loaded.__loader__, self.spec.loader)
         self.assertEqual(loaded.__package__, self.spec.parent)
@@ -461,7 +325,7 @@ class ModuleSpecMethodsTests:
                 return module
         self.spec.loader = ImmutableLoader()
         with CleanImport(self.spec.name):
-            loaded = self.bootstrap._SpecMethods(self.spec).load()
+            loaded = self.bootstrap._load(self.spec)
 
             self.assertIs(sys.modules[self.spec.name], module)
 
@@ -470,8 +334,8 @@ class ModuleSpecMethodsTests:
     def test_reload(self):
         self.spec.loader = NewLoader()
         with CleanImport(self.spec.name):
-            loaded = self.bootstrap._SpecMethods(self.spec).load()
-            reloaded = self.bootstrap._SpecMethods(self.spec).exec(loaded)
+            loaded = self.bootstrap._load(self.spec)
+            reloaded = self.bootstrap._exec(self.spec, loaded)
             installed = sys.modules[self.spec.name]
 
         self.assertEqual(loaded.eggs, 1)
@@ -481,9 +345,9 @@ class ModuleSpecMethodsTests:
     def test_reload_modified(self):
         self.spec.loader = NewLoader()
         with CleanImport(self.spec.name):
-            loaded = self.bootstrap._SpecMethods(self.spec).load()
+            loaded = self.bootstrap._load(self.spec)
             loaded.eggs = 2
-            reloaded = self.bootstrap._SpecMethods(self.spec).exec(loaded)
+            reloaded = self.bootstrap._exec(self.spec, loaded)
 
         self.assertEqual(loaded.eggs, 1)
         self.assertIs(reloaded, loaded)
@@ -491,9 +355,9 @@ class ModuleSpecMethodsTests:
     def test_reload_extra_attributes(self):
         self.spec.loader = NewLoader()
         with CleanImport(self.spec.name):
-            loaded = self.bootstrap._SpecMethods(self.spec).load()
+            loaded = self.bootstrap._load(self.spec)
             loaded.available = False
-            reloaded = self.bootstrap._SpecMethods(self.spec).exec(loaded)
+            reloaded = self.bootstrap._exec(self.spec, loaded)
 
         self.assertFalse(loaded.available)
         self.assertIs(reloaded, loaded)
@@ -501,12 +365,12 @@ class ModuleSpecMethodsTests:
     def test_reload_init_module_attrs(self):
         self.spec.loader = NewLoader()
         with CleanImport(self.spec.name):
-            loaded = self.bootstrap._SpecMethods(self.spec).load()
+            loaded = self.bootstrap._load(self.spec)
             loaded.__name__ = 'ham'
             del loaded.__loader__
             del loaded.__package__
             del loaded.__spec__
-            self.bootstrap._SpecMethods(self.spec).exec(loaded)
+            self.bootstrap._exec(self.spec, loaded)
 
         self.assertEqual(loaded.__name__, self.spec.name)
         self.assertIs(loaded.__loader__, self.spec.loader)
@@ -519,8 +383,8 @@ class ModuleSpecMethodsTests:
     def test_reload_legacy(self):
         self.spec.loader = LegacyLoader()
         with CleanImport(self.spec.name):
-            loaded = self.bootstrap._SpecMethods(self.spec).load()
-            reloaded = self.bootstrap._SpecMethods(self.spec).exec(loaded)
+            loaded = self.bootstrap._load(self.spec)
+            reloaded = self.bootstrap._exec(self.spec, loaded)
             installed = sys.modules[self.spec.name]
 
         self.assertEqual(loaded.ham, -1)
@@ -528,20 +392,18 @@ class ModuleSpecMethodsTests:
         self.assertIs(installed, loaded)
 
 
-class Frozen_ModuleSpecMethodsTests(ModuleSpecMethodsTests, unittest.TestCase):
-    bootstrap = frozen_bootstrap
-    machinery = frozen_machinery
-    util = frozen_util
-
-
-class Source_ModuleSpecMethodsTests(ModuleSpecMethodsTests, unittest.TestCase):
-    bootstrap = source_bootstrap
-    machinery = source_machinery
-    util = source_util
+(Frozen_ModuleSpecMethodsTests,
+ Source_ModuleSpecMethodsTests
+ ) = test_util.test_both(ModuleSpecMethodsTests, init=init, util=util,
+                         machinery=machinery)
 
 
 class ModuleReprTests:
 
+    @property
+    def bootstrap(self):
+        return self.init._bootstrap
+
     def setUp(self):
         self.module = type(os)('spam')
         self.spec = self.machinery.ModuleSpec('spam', TestLoader())
@@ -625,16 +487,10 @@ class ModuleReprTests:
         self.assertEqual(modrepr, '<module {!r}>'.format('spam'))
 
 
-class Frozen_ModuleReprTests(ModuleReprTests, unittest.TestCase):
-    bootstrap = frozen_bootstrap
-    machinery = frozen_machinery
-    util = frozen_util
-
-
-class Source_ModuleReprTests(ModuleReprTests, unittest.TestCase):
-    bootstrap = source_bootstrap
-    machinery = source_machinery
-    util = source_util
+(Frozen_ModuleReprTests,
+ Source_ModuleReprTests
+ ) = test_util.test_both(ModuleReprTests, init=init, util=util,
+                         machinery=machinery)
 
 
 class FactoryTests:
@@ -787,13 +643,14 @@ class FactoryTests:
     # spec_from_file_location()
 
     def test_spec_from_file_location_default(self):
-        if self.machinery is source_machinery:
-            raise unittest.SkipTest('not sure why this is breaking...')
         spec = self.util.spec_from_file_location(self.name, self.path)
 
         self.assertEqual(spec.name, self.name)
+        # Need to use a circuitous route to get at importlib.machinery to make
+        # sure the same class object is used in the isinstance() check as
+        # would have been used to create the loader.
         self.assertIsInstance(spec.loader,
-                              self.machinery.SourceFileLoader)
+                              self.util.abc.machinery.SourceFileLoader)
         self.assertEqual(spec.loader.name, self.name)
         self.assertEqual(spec.loader.path, self.path)
         self.assertEqual(spec.origin, self.path)
@@ -947,11 +804,10 @@ class FactoryTests:
         self.assertTrue(spec.has_location)
 
 
-class Frozen_FactoryTests(FactoryTests, unittest.TestCase):
-    util = frozen_util
-    machinery = frozen_machinery
+(Frozen_FactoryTests,
+ Source_FactoryTests
+ ) = test_util.test_both(FactoryTests, util=util, machinery=machinery)
 
 
-class Source_FactoryTests(FactoryTests, unittest.TestCase):
-    util = source_util
-    machinery = source_machinery
+if __name__ == '__main__':
+    unittest.main()
diff --git a/Lib/test/test_importlib/test_util.py b/Lib/test/test_importlib/test_util.py
index b2823c6a78..2493af7dea 100644
--- a/Lib/test/test_importlib/test_util.py
+++ b/Lib/test/test_importlib/test_util.py
@@ -1,8 +1,8 @@
-from importlib import util
-from . import util as test_util
-frozen_init, source_init = test_util.import_importlib('importlib')
-frozen_machinery, source_machinery = test_util.import_importlib('importlib.machinery')
-frozen_util, source_util = test_util.import_importlib('importlib.util')
+from . import util
+abc = util.import_importlib('importlib.abc')
+init = util.import_importlib('importlib')
+machinery = util.import_importlib('importlib.machinery')
+importlib_util = util.import_importlib('importlib.util')
 
 import os
 import sys
@@ -32,8 +32,94 @@ class DecodeSourceBytesTests:
         self.assertEqual(self.util.decode_source(source_bytes),
                          '\n'.join([self.source, self.source]))
 
-Frozen_DecodeSourceBytesTests, Source_DecodeSourceBytesTests = test_util.test_both(
-        DecodeSourceBytesTests, util=[frozen_util, source_util])
+
+(Frozen_DecodeSourceBytesTests,
+ Source_DecodeSourceBytesTests
+ ) = util.test_both(DecodeSourceBytesTests, util=importlib_util)
+
+
+class ModuleFromSpecTests:
+
+    def test_no_create_module(self):
+        class Loader:
+            def exec_module(self, module):
+                pass
+        spec = self.machinery.ModuleSpec('test', Loader())
+        with warnings.catch_warnings(record=True) as w:
+            warnings.simplefilter('always')
+            module = self.util.module_from_spec(spec)
+        self.assertEqual(1, len(w))
+        self.assertTrue(issubclass(w[0].category, DeprecationWarning))
+        self.assertIn('create_module', str(w[0].message))
+        self.assertIsInstance(module, types.ModuleType)
+        self.assertEqual(module.__name__, spec.name)
+
+    def test_create_module_returns_None(self):
+        class Loader(self.abc.Loader):
+            def create_module(self, spec):
+                return None
+        spec = self.machinery.ModuleSpec('test', Loader())
+        module = self.util.module_from_spec(spec)
+        self.assertIsInstance(module, types.ModuleType)
+        self.assertEqual(module.__name__, spec.name)
+
+    def test_create_module(self):
+        name = 'already set'
+        class CustomModule(types.ModuleType):
+            pass
+        class Loader(self.abc.Loader):
+            def create_module(self, spec):
+                module = CustomModule(spec.name)
+                module.__name__ = name
+                return module
+        spec = self.machinery.ModuleSpec('test', Loader())
+        module = self.util.module_from_spec(spec)
+        self.assertIsInstance(module, CustomModule)
+        self.assertEqual(module.__name__, name)
+
+    def test___name__(self):
+        spec = self.machinery.ModuleSpec('test', object())
+        module = self.util.module_from_spec(spec)
+        self.assertEqual(module.__name__, spec.name)
+
+    def test___spec__(self):
+        spec = self.machinery.ModuleSpec('test', object())
+        module = self.util.module_from_spec(spec)
+        self.assertEqual(module.__spec__, spec)
+
+    def test___loader__(self):
+        loader = object()
+        spec = self.machinery.ModuleSpec('test', loader)
+        module = self.util.module_from_spec(spec)
+        self.assertIs(module.__loader__, loader)
+
+    def test___package__(self):
+        spec = self.machinery.ModuleSpec('test.pkg', object())
+        module = self.util.module_from_spec(spec)
+        self.assertEqual(module.__package__, spec.parent)
+
+    def test___path__(self):
+        spec = self.machinery.ModuleSpec('test', object(), is_package=True)
+        module = self.util.module_from_spec(spec)
+        self.assertEqual(module.__path__, spec.submodule_search_locations)
+
+    def test___file__(self):
+        spec = self.machinery.ModuleSpec('test', object(), origin='some/path')
+        spec.has_location = True
+        module = self.util.module_from_spec(spec)
+        self.assertEqual(module.__file__, spec.origin)
+
+    def test___cached__(self):
+        spec = self.machinery.ModuleSpec('test', object())
+        spec.cached = 'some/path'
+        spec.has_location = True
+        module = self.util.module_from_spec(spec)
+        self.assertEqual(module.__cached__, spec.cached)
+
+(Frozen_ModuleFromSpecTests,
+ Source_ModuleFromSpecTests
+) = util.test_both(ModuleFromSpecTests, abc=abc, machinery=machinery,
+                   util=importlib_util)
 
 
 class ModuleForLoaderTests:
@@ -70,7 +156,7 @@ class ModuleForLoaderTests:
         # Test that when no module exists in sys.modules a new module is
         # created.
         module_name = 'a.b.c'
-        with test_util.uncache(module_name):
+        with util.uncache(module_name):
             module = self.return_module(module_name)
             self.assertIn(module_name, sys.modules)
         self.assertIsInstance(module, types.ModuleType)
@@ -88,7 +174,7 @@ class ModuleForLoaderTests:
         module = types.ModuleType('a.b.c')
         module.__loader__ = 42
         module.__package__ = 42
-        with test_util.uncache(name):
+        with util.uncache(name):
             sys.modules[name] = module
             loader = FakeLoader()
             returned_module = loader.load_module(name)
@@ -100,7 +186,7 @@ class ModuleForLoaderTests:
         # Test that a module is removed from sys.modules if added but an
         # exception is raised.
         name = 'a.b.c'
-        with test_util.uncache(name):
+        with util.uncache(name):
             self.raise_exception(name)
             self.assertNotIn(name, sys.modules)
 
@@ -108,7 +194,7 @@ class ModuleForLoaderTests:
         # Test that a failure on reload leaves the module in-place.
         name = 'a.b.c'
         module = types.ModuleType(name)
-        with test_util.uncache(name):
+        with util.uncache(name):
             sys.modules[name] = module
             self.raise_exception(name)
             self.assertIs(module, sys.modules[name])
@@ -127,7 +213,7 @@ class ModuleForLoaderTests:
 
         name = 'mod'
         module = FalseModule(name)
-        with test_util.uncache(name):
+        with util.uncache(name):
             self.assertFalse(module)
             sys.modules[name] = module
             given = self.return_module(name)
@@ -146,7 +232,7 @@ class ModuleForLoaderTests:
                 return module
 
         name = 'pkg.mod'
-        with test_util.uncache(name):
+        with util.uncache(name):
             loader = FakeLoader(False)
             module = loader.load_module(name)
             self.assertEqual(module.__name__, name)
@@ -154,15 +240,17 @@ class ModuleForLoaderTests:
             self.assertEqual(module.__package__, 'pkg')
 
         name = 'pkg.sub'
-        with test_util.uncache(name):
+        with util.uncache(name):
             loader = FakeLoader(True)
             module = loader.load_module(name)
             self.assertEqual(module.__name__, name)
             self.assertIs(module.__loader__, loader)
             self.assertEqual(module.__package__, name)
 
-Frozen_ModuleForLoaderTests, Source_ModuleForLoaderTests = test_util.test_both(
-        ModuleForLoaderTests, util=[frozen_util, source_util])
+
+(Frozen_ModuleForLoaderTests,
+ Source_ModuleForLoaderTests
+ ) = util.test_both(ModuleForLoaderTests, util=importlib_util)
 
 
 class SetPackageTests:
@@ -222,18 +310,25 @@ class SetPackageTests:
         self.assertEqual(wrapped.__name__, fxn.__name__)
         self.assertEqual(wrapped.__qualname__, fxn.__qualname__)
 
-Frozen_SetPackageTests, Source_SetPackageTests = test_util.test_both(
-        SetPackageTests, util=[frozen_util, source_util])
+
+(Frozen_SetPackageTests,
+ Source_SetPackageTests
+ ) = util.test_both(SetPackageTests, util=importlib_util)
 
 
 class SetLoaderTests:
 
     """Tests importlib.util.set_loader()."""
 
-    class DummyLoader:
-        @util.set_loader
-        def load_module(self, module):
-            return self.module
+    @property
+    def DummyLoader(self):
+        # Set DummyLoader on the class lazily.
+        class DummyLoader:
+            @self.util.set_loader
+            def load_module(self, module):
+                return self.module
+        self.__class__.DummyLoader = DummyLoader
+        return DummyLoader
 
     def test_no_attribute(self):
         loader = self.DummyLoader()
@@ -262,17 +357,10 @@ class SetLoaderTests:
             warnings.simplefilter('ignore', DeprecationWarning)
             self.assertEqual(42, loader.load_module('blah').__loader__)
 
-class Frozen_SetLoaderTests(SetLoaderTests, unittest.TestCase):
-    class DummyLoader:
-        @frozen_util.set_loader
-        def load_module(self, module):
-            return self.module
 
-class Source_SetLoaderTests(SetLoaderTests, unittest.TestCase):
-    class DummyLoader:
-        @source_util.set_loader
-        def load_module(self, module):
-            return self.module
+(Frozen_SetLoaderTests,
+ Source_SetLoaderTests
+ ) = util.test_both(SetLoaderTests, util=importlib_util)
 
 
 class ResolveNameTests:
@@ -307,9 +395,10 @@ class ResolveNameTests:
         with self.assertRaises(ValueError):
             self.util.resolve_name('..bacon', 'spam')
 
-Frozen_ResolveNameTests, Source_ResolveNameTests = test_util.test_both(
-        ResolveNameTests,
-        util=[frozen_util, source_util])
+
+(Frozen_ResolveNameTests,
+ Source_ResolveNameTests
+ ) = util.test_both(ResolveNameTests, util=importlib_util)
 
 
 class FindSpecTests:
@@ -320,7 +409,7 @@ class FindSpecTests:
 
     def test_sys_modules(self):
         name = 'some_mod'
-        with test_util.uncache(name):
+        with util.uncache(name):
             module = types.ModuleType(name)
             loader = 'a loader!'
             spec = self.machinery.ModuleSpec(name, loader)
@@ -332,7 +421,7 @@ class FindSpecTests:
 
     def test_sys_modules_without___loader__(self):
         name = 'some_mod'
-        with test_util.uncache(name):
+        with util.uncache(name):
             module = types.ModuleType(name)
             del module.__loader__
             loader = 'a loader!'
@@ -344,7 +433,7 @@ class FindSpecTests:
 
     def test_sys_modules_spec_is_None(self):
         name = 'some_mod'
-        with test_util.uncache(name):
+        with util.uncache(name):
             module = types.ModuleType(name)
             module.__spec__ = None
             sys.modules[name] = module
@@ -353,7 +442,7 @@ class FindSpecTests:
 
     def test_sys_modules_loader_is_None(self):
         name = 'some_mod'
-        with test_util.uncache(name):
+        with util.uncache(name):
             module = types.ModuleType(name)
             spec = self.machinery.ModuleSpec(name, None)
             module.__spec__ = spec
@@ -363,7 +452,7 @@ class FindSpecTests:
 
     def test_sys_modules_spec_is_not_set(self):
         name = 'some_mod'
-        with test_util.uncache(name):
+        with util.uncache(name):
             module = types.ModuleType(name)
             try:
                 del module.__spec__
@@ -375,8 +464,8 @@ class FindSpecTests:
 
     def test_success(self):
         name = 'some_mod'
-        with test_util.uncache(name):
-            with test_util.import_state(meta_path=[self.FakeMetaFinder]):
+        with util.uncache(name):
+            with util.import_state(meta_path=[self.FakeMetaFinder]):
                 self.assertEqual((name, None, None),
                                  self.util.find_spec(name))
 
@@ -384,8 +473,8 @@ class FindSpecTests:
 #        # Searching on a path should work.
 #        name = 'some_mod'
 #        path = 'path to some place'
-#        with test_util.uncache(name):
-#            with test_util.import_state(meta_path=[self.FakeMetaFinder]):
+#        with util.uncache(name):
+#            with util.import_state(meta_path=[self.FakeMetaFinder]):
 #                self.assertEqual((name, path, None),
 #                                 self.util.find_spec(name, path))
 
@@ -396,8 +485,8 @@ class FindSpecTests:
     def test_find_submodule(self):
         name = 'spam'
         subname = 'ham'
-        with test_util.temp_module(name, pkg=True) as pkg_dir:
-            fullname, _ = test_util.submodule(name, subname, pkg_dir)
+        with util.temp_module(name, pkg=True) as pkg_dir:
+            fullname, _ = util.submodule(name, subname, pkg_dir)
             spec = self.util.find_spec(fullname)
             self.assertIsNot(spec, None)
             self.assertIn(name, sorted(sys.modules))
@@ -409,9 +498,9 @@ class FindSpecTests:
     def test_find_submodule_parent_already_imported(self):
         name = 'spam'
         subname = 'ham'
-        with test_util.temp_module(name, pkg=True) as pkg_dir:
+        with util.temp_module(name, pkg=True) as pkg_dir:
             self.init.import_module(name)
-            fullname, _ = test_util.submodule(name, subname, pkg_dir)
+            fullname, _ = util.submodule(name, subname, pkg_dir)
             spec = self.util.find_spec(fullname)
             self.assertIsNot(spec, None)
             self.assertIn(name, sorted(sys.modules))
@@ -423,8 +512,8 @@ class FindSpecTests:
     def test_find_relative_module(self):
         name = 'spam'
         subname = 'ham'
-        with test_util.temp_module(name, pkg=True) as pkg_dir:
-            fullname, _ = test_util.submodule(name, subname, pkg_dir)
+        with util.temp_module(name, pkg=True) as pkg_dir:
+            fullname, _ = util.submodule(name, subname, pkg_dir)
             relname = '.' + subname
             spec = self.util.find_spec(relname, name)
             self.assertIsNot(spec, None)
@@ -437,8 +526,8 @@ class FindSpecTests:
     def test_find_relative_module_missing_package(self):
         name = 'spam'
         subname = 'ham'
-        with test_util.temp_module(name, pkg=True) as pkg_dir:
-            fullname, _ = test_util.submodule(name, subname, pkg_dir)
+        with util.temp_module(name, pkg=True) as pkg_dir:
+            fullname, _ = util.submodule(name, subname, pkg_dir)
             relname = '.' + subname
             with self.assertRaises(ValueError):
                 self.util.find_spec(relname)
@@ -446,15 +535,10 @@ class FindSpecTests:
             self.assertNotIn(fullname, sorted(sys.modules))
 
 
-class Frozen_FindSpecTests(FindSpecTests, unittest.TestCase):
-    init = frozen_init
-    machinery = frozen_machinery
-    util = frozen_util
-
-class Source_FindSpecTests(FindSpecTests, unittest.TestCase):
-    init = source_init
-    machinery = source_machinery
-    util = source_util
+(Frozen_FindSpecTests,
+ Source_FindSpecTests
+ ) = util.test_both(FindSpecTests, init=init, util=importlib_util,
+                         machinery=machinery)
 
 
 class MagicNumberTests:
@@ -467,8 +551,10 @@ class MagicNumberTests:
         # The magic number uses \r\n to come out wrong when splitting on lines.
         self.assertTrue(self.util.MAGIC_NUMBER.endswith(b'\r\n'))
 
-Frozen_MagicNumberTests, Source_MagicNumberTests = test_util.test_both(
-        MagicNumberTests, util=[frozen_util, source_util])
+
+(Frozen_MagicNumberTests,
+ Source_MagicNumberTests
+ ) = util.test_both(MagicNumberTests, util=importlib_util)
 
 
 class PEP3147Tests:
@@ -583,9 +669,10 @@ class PEP3147Tests:
             ValueError, self.util.source_from_cache,
             '/foo/bar/foo.cpython-32.foo.pyc')
 
-Frozen_PEP3147Tests, Source_PEP3147Tests = test_util.test_both(
-        PEP3147Tests,
-        util=[frozen_util, source_util])
+
+(Frozen_PEP3147Tests,
+ Source_PEP3147Tests
+ ) = util.test_both(PEP3147Tests, util=importlib_util)
 
 
 if __name__ == '__main__':
diff --git a/Lib/test/test_importlib/test_windows.py b/Lib/test/test_importlib/test_windows.py
index 96b4adcd05..c893bcf565 100644
--- a/Lib/test/test_importlib/test_windows.py
+++ b/Lib/test/test_importlib/test_windows.py
@@ -1,14 +1,64 @@
-from . import util
-frozen_machinery, source_machinery = util.import_importlib('importlib.machinery')
+from . import util as test_util
+machinery = test_util.import_importlib('importlib.machinery')
 
+import os
+import re
 import sys
 import unittest
+from test import support
+from distutils.util import get_platform
+from contextlib import contextmanager
+from .util import temp_module
+
+support.import_module('winreg', required_on=['win'])
+from winreg import (
+    CreateKey, HKEY_CURRENT_USER,
+    SetValue, REG_SZ, KEY_ALL_ACCESS,
+    EnumKey, CloseKey, DeleteKey, OpenKey
+)
+
+def delete_registry_tree(root, subkey):
+    try:
+        hkey = OpenKey(root, subkey, access=KEY_ALL_ACCESS)
+    except OSError:
+        # subkey does not exist
+        return
+    while True:
+        try:
+            subsubkey = EnumKey(hkey, 0)
+        except OSError:
+            # no more subkeys
+            break
+        delete_registry_tree(hkey, subsubkey)
+    CloseKey(hkey)
+    DeleteKey(root, subkey)
+
+@contextmanager
+def setup_module(machinery, name, path=None):
+    if machinery.WindowsRegistryFinder.DEBUG_BUILD:
+        root = machinery.WindowsRegistryFinder.REGISTRY_KEY_DEBUG
+    else:
+        root = machinery.WindowsRegistryFinder.REGISTRY_KEY
+    key = root.format(fullname=name,
+                      sys_version=sys.version[:3])
+    try:
+        with temp_module(name, "a = 1") as location:
+            subkey = CreateKey(HKEY_CURRENT_USER, key)
+            if path is None:
+                path = location + ".py"
+            SetValue(subkey, "", REG_SZ, path)
+            yield
+    finally:
+        if machinery.WindowsRegistryFinder.DEBUG_BUILD:
+            key = os.path.dirname(key)
+        delete_registry_tree(HKEY_CURRENT_USER, key)
 
 
 @unittest.skipUnless(sys.platform.startswith('win'), 'requires Windows')
 class WindowsRegistryFinderTests:
-
-    # XXX Need a test that finds the spec via the registry.
+    # The module name is process-specific, allowing for
+    # simultaneous runs of the same test on a single machine.
+    test_module = "spamham{}".format(os.getpid())
 
     def test_find_spec_missing(self):
         spec = self.machinery.WindowsRegistryFinder.find_spec('spam')
@@ -18,12 +68,42 @@ class WindowsRegistryFinderTests:
         loader = self.machinery.WindowsRegistryFinder.find_module('spam')
         self.assertIs(loader, None)
 
+    def test_module_found(self):
+        with setup_module(self.machinery, self.test_module):
+            loader = self.machinery.WindowsRegistryFinder.find_module(self.test_module)
+            spec = self.machinery.WindowsRegistryFinder.find_spec(self.test_module)
+            self.assertIsNot(loader, None)
+            self.assertIsNot(spec, None)
+
+    def test_module_not_found(self):
+        with setup_module(self.machinery, self.test_module, path="."):
+            loader = self.machinery.WindowsRegistryFinder.find_module(self.test_module)
+            spec = self.machinery.WindowsRegistryFinder.find_spec(self.test_module)
+            self.assertIsNone(loader)
+            self.assertIsNone(spec)
+
+(Frozen_WindowsRegistryFinderTests,
+ Source_WindowsRegistryFinderTests
+ ) = test_util.test_both(WindowsRegistryFinderTests, machinery=machinery)
+
+@unittest.skipUnless(sys.platform.startswith('win'), 'requires Windows')
+class WindowsExtensionSuffixTests:
+    def test_tagged_suffix(self):
+        suffixes = self.machinery.EXTENSION_SUFFIXES
+        expected_tag = ".cp{0.major}{0.minor}-{1}.pyd".format(sys.version_info,
+            re.sub('[^a-zA-Z0-9]', '_', get_platform()))
+        try:
+            untagged_i = suffixes.index(".pyd")
+        except ValueError:
+            untagged_i = suffixes.index("_d.pyd")
+            expected_tag = "_d" + expected_tag
 
-class Frozen_WindowsRegistryFinderTests(WindowsRegistryFinderTests,
-                                        unittest.TestCase):
-    machinery = frozen_machinery
+        self.assertIn(expected_tag, suffixes)
 
+        # Ensure the tags are in the correct order
+        tagged_i = suffixes.index(expected_tag)
+        self.assertLess(tagged_i, untagged_i)
 
-class Source_WindowsRegistryFinderTests(WindowsRegistryFinderTests,
-                                        unittest.TestCase):
-    machinery = source_machinery
+(Frozen_WindowsExtensionSuffixTests,
+ Source_WindowsExtensionSuffixTests
+ ) = test_util.test_both(WindowsExtensionSuffixTests, machinery=machinery)
diff --git a/Lib/test/test_importlib/util.py b/Lib/test/test_importlib/util.py
index 885cec3b29..aa4cd7e861 100644
--- a/Lib/test/test_importlib/util.py
+++ b/Lib/test/test_importlib/util.py
@@ -1,31 +1,85 @@
-from contextlib import contextmanager
-from importlib import util, invalidate_caches
+import builtins
+import contextlib
+import errno
+import functools
+import importlib
+from importlib import machinery, util, invalidate_caches
+import os
 import os.path
 from test import support
 import unittest
 import sys
+import tempfile
 import types
 
 
+BUILTINS = types.SimpleNamespace()
+BUILTINS.good_name = None
+BUILTINS.bad_name = None
+if 'errno' in sys.builtin_module_names:
+    BUILTINS.good_name = 'errno'
+if 'importlib' not in sys.builtin_module_names:
+    BUILTINS.bad_name = 'importlib'
+
+EXTENSIONS = types.SimpleNamespace()
+EXTENSIONS.path = None
+EXTENSIONS.ext = None
+EXTENSIONS.filename = None
+EXTENSIONS.file_path = None
+EXTENSIONS.name = '_testcapi'
+
+def _extension_details():
+    global EXTENSIONS
+    for path in sys.path:
+        for ext in machinery.EXTENSION_SUFFIXES:
+            filename = EXTENSIONS.name + ext
+            file_path = os.path.join(path, filename)
+            if os.path.exists(file_path):
+                EXTENSIONS.path = path
+                EXTENSIONS.ext = ext
+                EXTENSIONS.filename = filename
+                EXTENSIONS.file_path = file_path
+                return
+
+_extension_details()
+
+
 def import_importlib(module_name):
     """Import a module from importlib both w/ and w/o _frozen_importlib."""
     fresh = ('importlib',) if '.' in module_name else ()
     frozen = support.import_fresh_module(module_name)
     source = support.import_fresh_module(module_name, fresh=fresh,
                                          blocked=('_frozen_importlib',))
+    return {'Frozen': frozen, 'Source': source}
+
+
+def specialize_class(cls, kind, base=None, **kwargs):
+    # XXX Support passing in submodule names--load (and cache) them?
+    # That would clean up the test modules a bit more.
+    if base is None:
+        base = unittest.TestCase
+    elif not isinstance(base, type):
+        base = base[kind]
+    name = '{}_{}'.format(kind, cls.__name__)
+    bases = (cls, base)
+    specialized = types.new_class(name, bases)
+    specialized.__module__ = cls.__module__
+    specialized._NAME = cls.__name__
+    specialized._KIND = kind
+    for attr, values in kwargs.items():
+        value = values[kind]
+        setattr(specialized, attr, value)
+    return specialized
+
+
+def split_frozen(cls, base=None, **kwargs):
+    frozen = specialize_class(cls, 'Frozen', base, **kwargs)
+    source = specialize_class(cls, 'Source', base, **kwargs)
     return frozen, source
 
 
-def test_both(test_class, **kwargs):
-    frozen_tests = types.new_class('Frozen_'+test_class.__name__,
-                                   (test_class, unittest.TestCase))
-    source_tests = types.new_class('Source_'+test_class.__name__,
-                                   (test_class, unittest.TestCase))
-    frozen_tests.__module__ = source_tests.__module__ = test_class.__module__
-    for attr, (frozen_value, source_value) in kwargs.items():
-        setattr(frozen_tests, attr, frozen_value)
-        setattr(source_tests, attr, source_value)
-    return frozen_tests, source_tests
+def test_both(test_class, base=None, **kwargs):
+    return split_frozen(test_class, base, **kwargs)
 
 
 CASE_INSENSITIVE_FS = True
@@ -38,6 +92,10 @@ if sys.platform not in ('win32', 'cygwin'):
     if not os.path.exists(changed_name):
         CASE_INSENSITIVE_FS = False
 
+source_importlib = import_importlib('importlib')['Source']
+__import__ = {'Frozen': staticmethod(builtins.__import__),
+              'Source': staticmethod(source_importlib.__import__)}
+
 
 def case_insensitive_tests(test):
     """Class decorator that nullifies tests requiring a case-insensitive
@@ -53,7 +111,7 @@ def submodule(parent, name, pkg_dir, content=''):
     return '{}.{}'.format(parent, name), path
 
 
-@contextmanager
+@contextlib.contextmanager
 def uncache(*names):
     """Uncache a module from sys.modules.
 
@@ -79,7 +137,7 @@ def uncache(*names):
                 pass
 
 
-@contextmanager
+@contextlib.contextmanager
 def temp_module(name, content='', *, pkg=False):
     conflicts = [n for n in sys.modules if n.partition('.')[0] == name]
     with support.temp_cwd(None) as cwd:
@@ -103,7 +161,7 @@ def temp_module(name, content='', *, pkg=False):
                 yield location
 
 
-@contextmanager
+@contextlib.contextmanager
 def import_state(**kwargs):
     """Context manager to manage the various importers and stored state in the
     sys module.
@@ -198,6 +256,7 @@ class mock_modules(_ImporterMock):
                     raise
             return self.modules[fullname]
 
+
 class mock_spec(_ImporterMock):
 
     """Importer mock using PEP 451 APIs."""
@@ -223,3 +282,99 @@ class mock_spec(_ImporterMock):
             self.module_code[module.__spec__.name]()
         except KeyError:
             pass
+
+
+def writes_bytecode_files(fxn):
+    """Decorator to protect sys.dont_write_bytecode from mutation and to skip
+    tests that require it to be set to False."""
+    if sys.dont_write_bytecode:
+        return lambda *args, **kwargs: None
+    @functools.wraps(fxn)
+    def wrapper(*args, **kwargs):
+        original = sys.dont_write_bytecode
+        sys.dont_write_bytecode = False
+        try:
+            to_return = fxn(*args, **kwargs)
+        finally:
+            sys.dont_write_bytecode = original
+        return to_return
+    return wrapper
+
+
+def ensure_bytecode_path(bytecode_path):
+    """Ensure that the __pycache__ directory for PEP 3147 pyc file exists.
+
+    :param bytecode_path: File system path to PEP 3147 pyc file.
+    """
+    try:
+        os.mkdir(os.path.dirname(bytecode_path))
+    except OSError as error:
+        if error.errno != errno.EEXIST:
+            raise
+
+
+@contextlib.contextmanager
+def create_modules(*names):
+    """Temporarily create each named module with an attribute (named 'attr')
+    that contains the name passed into the context manager that caused the
+    creation of the module.
+
+    All files are created in a temporary directory returned by
+    tempfile.mkdtemp(). This directory is inserted at the beginning of
+    sys.path. When the context manager exits all created files (source and
+    bytecode) are explicitly deleted.
+
+    No magic is performed when creating packages! This means that if you create
+    a module within a package you must also create the package's __init__ as
+    well.
+
+    """
+    source = 'attr = {0!r}'
+    created_paths = []
+    mapping = {}
+    state_manager = None
+    uncache_manager = None
+    try:
+        temp_dir = tempfile.mkdtemp()
+        mapping['.root'] = temp_dir
+        import_names = set()
+        for name in names:
+            if not name.endswith('__init__'):
+                import_name = name
+            else:
+                import_name = name[:-len('.__init__')]
+            import_names.add(import_name)
+            if import_name in sys.modules:
+                del sys.modules[import_name]
+            name_parts = name.split('.')
+            file_path = temp_dir
+            for directory in name_parts[:-1]:
+                file_path = os.path.join(file_path, directory)
+                if not os.path.exists(file_path):
+                    os.mkdir(file_path)
+                    created_paths.append(file_path)
+            file_path = os.path.join(file_path, name_parts[-1] + '.py')
+            with open(file_path, 'w') as file:
+                file.write(source.format(name))
+            created_paths.append(file_path)
+            mapping[name] = file_path
+        uncache_manager = uncache(*import_names)
+        uncache_manager.__enter__()
+        state_manager = import_state(path=[temp_dir])
+        state_manager.__enter__()
+        yield mapping
+    finally:
+        if state_manager is not None:
+            state_manager.__exit__(None, None, None)
+        if uncache_manager is not None:
+            uncache_manager.__exit__(None, None, None)
+        support.rmtree(temp_dir)
+
+
+def mock_path_hook(*entries, importer):
+    """A mock sys.path_hooks entry."""
+    def hook(entry):
+        if entry not in entries:
+            raise ImportError
+        return importer
+    return hook
diff --git a/Lib/test/test_inspect.py b/Lib/test/test_inspect.py
index fc3bf07f1c..bbc53856f1 100644
--- a/Lib/test/test_inspect.py
+++ b/Lib/test/test_inspect.py
@@ -1,3 +1,4 @@
+import builtins
 import collections
 import datetime
 import functools
@@ -8,6 +9,7 @@ import linecache
 import os
 from os.path import normcase
 import _pickle
+import pickle
 import re
 import shutil
 import sys
@@ -23,7 +25,7 @@ except ImportError:
     ThreadPoolExecutor = None
 
 from test.support import run_unittest, TESTFN, DirsOnSysPath, cpython_only
-from test.support import MISSING_C_DOCSTRINGS
+from test.support import MISSING_C_DOCSTRINGS, cpython_only
 from test.script_helper import assert_python_ok, assert_python_failure
 from test import inspect_fodder as mod
 from test import inspect_fodder2 as mod2
@@ -76,6 +78,7 @@ def generator_function_example(self):
     for i in range(2):
         yield i
 
+
 class TestPredicates(IsTestBase):
     def test_sixteen(self):
         count = len([x for x in dir(inspect) if x.startswith('is')])
@@ -182,6 +185,14 @@ class TestInterpreterStack(IsTestBase):
              (modfile, 43, 'argue', ['            spam(a, b, c)\n'], 0))
         self.assertEqual(revise(*mod.st[3][1:]),
              (modfile, 39, 'abuse', ['        self.argue(a, b, c)\n'], 0))
+        # Test named tuple fields
+        record = mod.st[0]
+        self.assertIs(record.frame, mod.fr)
+        self.assertEqual(record.lineno, 16)
+        self.assertEqual(record.filename, mod.__file__)
+        self.assertEqual(record.function, 'eggs')
+        self.assertIn('inspect.stack()', record.code_context[0])
+        self.assertEqual(record.index, 0)
 
     def test_trace(self):
         self.assertEqual(len(git.tr), 3)
@@ -369,6 +380,9 @@ class TestDecorators(GetSourceBase):
     def test_replacing_decorator(self):
         self.assertSourceEqual(mod2.gone, 9, 10)
 
+    def test_getsource_unwrap(self):
+        self.assertSourceEqual(mod2.real, 122, 124)
+
 class TestOneliners(GetSourceBase):
     fodderModule = mod2
     def test_oneline_lambda(self):
@@ -1615,6 +1629,68 @@ class TestGetGeneratorState(unittest.TestCase):
         self.assertRaises(TypeError, inspect.getgeneratorlocals, (2,3))
 
 
+class MySignature(inspect.Signature):
+    # Top-level to make it picklable;
+    # used in test_signature_object_pickle
+    pass
+
+class MyParameter(inspect.Parameter):
+    # Top-level to make it picklable;
+    # used in test_signature_object_pickle
+    pass
+
+    @cpython_only
+    @unittest.skipIf(MISSING_C_DOCSTRINGS,
+                     "Signature information for builtins requires docstrings")
+    def test_builtins_have_signatures(self):
+        # This checks all builtin callables in CPython have signatures
+        # A few have signatures Signature can't yet handle, so we skip those
+        # since they will have to wait until PEP 457 adds the required
+        # introspection support to the inspect module
+        # Some others also haven't been converted yet for various other
+        # reasons, so we also skip those for the time being, but design
+        # the test to fail in order to indicate when it needs to be
+        # updated.
+        no_signature = set()
+        # These need PEP 457 groups
+        needs_groups = ["range", "slice", "dir", "getattr",
+                        "next", "iter", "vars"]
+        no_signature |= needs_groups
+        # These need PEP 457 groups or a signature change to accept None
+        needs_semantic_update = ["round"]
+        no_signature |= needs_semantic_update
+        # These need *args support in Argument Clinic
+        needs_varargs = ["min", "max", "print", "__build_class__"]
+        no_signature |= needs_varargs
+        # These simply weren't covered in the initial AC conversion
+        # for builtin callables
+        not_converted_yet = ["open", "__import__"]
+        no_signature |= not_converted_yet
+        # These builtin types are expected to provide introspection info
+        types_with_signatures = set()
+        # Check the signatures we expect to be there
+        ns = vars(builtins)
+        for name, obj in sorted(ns.items()):
+            if not callable(obj):
+                continue
+            # The builtin types haven't been converted to AC yet
+            if isinstance(obj, type) and (name not in types_with_signatures):
+                # Note that this also skips all the exception types
+                no_signature.append(name)
+            if (name in no_signature):
+                # Not yet converted
+                continue
+            with self.subTest(builtin=name):
+                self.assertIsNotNone(inspect.signature(obj))
+        # Check callables that haven't been converted don't claim a signature
+        # This ensures this test will start failing as more signatures are
+        # added, so the affected items can be moved into the scope of the
+        # regression test above
+        for name in no_signature:
+            with self.subTest(builtin=name):
+                self.assertIsNone(ns[name].__text_signature__)
+
+
 class TestSignatureObject(unittest.TestCase):
     @staticmethod
     def signature(func):
@@ -1672,6 +1748,37 @@ class TestSignatureObject(unittest.TestCase):
         with self.assertRaisesRegex(ValueError, 'follows default argument'):
             S((pkd, pk))
 
+        self.assertTrue(repr(sig).startswith('<Signature'))
+        self.assertTrue('"(po, pk' in repr(sig))
+
+    def test_signature_object_pickle(self):
+        def foo(a, b, *, c:1={}, **kw) -> {42:'ham'}: pass
+        foo_partial = functools.partial(foo, a=1)
+
+        sig = inspect.signature(foo_partial)
+
+        for ver in range(pickle.HIGHEST_PROTOCOL + 1):
+            with self.subTest(pickle_ver=ver, subclass=False):
+                sig_pickled = pickle.loads(pickle.dumps(sig, ver))
+                self.assertEqual(sig, sig_pickled)
+
+        # Test that basic sub-classing works
+        sig = inspect.signature(foo)
+        myparam = MyParameter(name='z', kind=inspect.Parameter.POSITIONAL_ONLY)
+        myparams = collections.OrderedDict(sig.parameters, a=myparam)
+        mysig = MySignature().replace(parameters=myparams.values(),
+                                      return_annotation=sig.return_annotation)
+        self.assertTrue(isinstance(mysig, MySignature))
+        self.assertTrue(isinstance(mysig.parameters['z'], MyParameter))
+
+        for ver in range(pickle.HIGHEST_PROTOCOL + 1):
+            with self.subTest(pickle_ver=ver, subclass=True):
+                sig_pickled = pickle.loads(pickle.dumps(mysig, ver))
+                self.assertEqual(mysig, sig_pickled)
+                self.assertTrue(isinstance(sig_pickled, MySignature))
+                self.assertTrue(isinstance(sig_pickled.parameters['z'],
+                                           MyParameter))
+
     def test_signature_immutability(self):
         def test(a):
             pass
@@ -2435,49 +2542,91 @@ class TestSignatureObject(unittest.TestCase):
 
         def bar(a, *, b:int) -> float: pass
         self.assertEqual(inspect.signature(foo), inspect.signature(bar))
+        self.assertEqual(
+            hash(inspect.signature(foo)), hash(inspect.signature(bar)))
 
         def bar(a, *, b:int) -> int: pass
         self.assertNotEqual(inspect.signature(foo), inspect.signature(bar))
+        self.assertNotEqual(
+            hash(inspect.signature(foo)), hash(inspect.signature(bar)))
 
         def bar(a, *, b:int): pass
         self.assertNotEqual(inspect.signature(foo), inspect.signature(bar))
+        self.assertNotEqual(
+            hash(inspect.signature(foo)), hash(inspect.signature(bar)))
 
         def bar(a, *, b:int=42) -> float: pass
         self.assertNotEqual(inspect.signature(foo), inspect.signature(bar))
+        self.assertNotEqual(
+            hash(inspect.signature(foo)), hash(inspect.signature(bar)))
 
         def bar(a, *, c) -> float: pass
         self.assertNotEqual(inspect.signature(foo), inspect.signature(bar))
+        self.assertNotEqual(
+            hash(inspect.signature(foo)), hash(inspect.signature(bar)))
 
         def bar(a, b:int) -> float: pass
         self.assertNotEqual(inspect.signature(foo), inspect.signature(bar))
+        self.assertNotEqual(
+            hash(inspect.signature(foo)), hash(inspect.signature(bar)))
         def spam(b:int, a) -> float: pass
         self.assertNotEqual(inspect.signature(spam), inspect.signature(bar))
+        self.assertNotEqual(
+            hash(inspect.signature(spam)), hash(inspect.signature(bar)))
 
         def foo(*, a, b, c): pass
         def bar(*, c, b, a): pass
         self.assertEqual(inspect.signature(foo), inspect.signature(bar))
+        self.assertEqual(
+            hash(inspect.signature(foo)), hash(inspect.signature(bar)))
 
         def foo(*, a=1, b, c): pass
         def bar(*, c, b, a=1): pass
         self.assertEqual(inspect.signature(foo), inspect.signature(bar))
+        self.assertEqual(
+            hash(inspect.signature(foo)), hash(inspect.signature(bar)))
 
         def foo(pos, *, a=1, b, c): pass
         def bar(pos, *, c, b, a=1): pass
         self.assertEqual(inspect.signature(foo), inspect.signature(bar))
+        self.assertEqual(
+            hash(inspect.signature(foo)), hash(inspect.signature(bar)))
 
         def foo(pos, *, a, b, c): pass
         def bar(pos, *, c, b, a=1): pass
         self.assertNotEqual(inspect.signature(foo), inspect.signature(bar))
+        self.assertNotEqual(
+            hash(inspect.signature(foo)), hash(inspect.signature(bar)))
 
         def foo(pos, *args, a=42, b, c, **kwargs:int): pass
         def bar(pos, *args, c, b, a=42, **kwargs:int): pass
         self.assertEqual(inspect.signature(foo), inspect.signature(bar))
+        self.assertEqual(
+            hash(inspect.signature(foo)), hash(inspect.signature(bar)))
+
+    def test_signature_hashable(self):
+        S = inspect.Signature
+        P = inspect.Parameter
 
-    def test_signature_unhashable(self):
         def foo(a): pass
-        sig = inspect.signature(foo)
+        foo_sig = inspect.signature(foo)
+
+        manual_sig = S(parameters=[P('a', P.POSITIONAL_OR_KEYWORD)])
+
+        self.assertEqual(hash(foo_sig), hash(manual_sig))
+        self.assertNotEqual(hash(foo_sig),
+                            hash(manual_sig.replace(return_annotation='spam')))
+
+        def bar(a) -> 1: pass
+        self.assertNotEqual(hash(foo_sig), hash(inspect.signature(bar)))
+
+        def foo(a={}): pass
         with self.assertRaisesRegex(TypeError, 'unhashable type'):
-            hash(sig)
+            hash(inspect.signature(foo))
+
+        def foo(a) -> {}: pass
+        with self.assertRaisesRegex(TypeError, 'unhashable type'):
+            hash(inspect.signature(foo))
 
     def test_signature_str(self):
         def foo(a:int=1, *, b, c=None, **kwargs) -> 42:
@@ -2551,6 +2700,19 @@ class TestSignatureObject(unittest.TestCase):
         self.assertEqual(self.signature(Spam.foo),
                          self.signature(Ham.foo))
 
+    def test_signature_from_callable_python_obj(self):
+        class MySignature(inspect.Signature): pass
+        def foo(a, *, b:1): pass
+        foo_sig = MySignature.from_callable(foo)
+        self.assertTrue(isinstance(foo_sig, MySignature))
+
+    @unittest.skipIf(MISSING_C_DOCSTRINGS,
+                     "Signature information for builtins requires docstrings")
+    def test_signature_from_callable_builtin_obj(self):
+        class MySignature(inspect.Signature): pass
+        sig = MySignature.from_callable(_pickle.Pickler)
+        self.assertTrue(isinstance(sig, MySignature))
+
 
 class TestParameterObject(unittest.TestCase):
     def test_signature_parameter_kinds(self):
@@ -2596,6 +2758,16 @@ class TestParameterObject(unittest.TestCase):
             p.replace(kind=inspect.Parameter.VAR_POSITIONAL)
 
         self.assertTrue(repr(p).startswith('<Parameter'))
+        self.assertTrue('"a=42"' in repr(p))
+
+    def test_signature_parameter_hashable(self):
+        P = inspect.Parameter
+        foo = P('foo', kind=P.POSITIONAL_ONLY)
+        self.assertEqual(hash(foo), hash(P('foo', kind=P.POSITIONAL_ONLY)))
+        self.assertNotEqual(hash(foo), hash(P('foo', kind=P.POSITIONAL_ONLY,
+                                              default=42)))
+        self.assertNotEqual(hash(foo),
+                            hash(foo.replace(kind=P.VAR_POSITIONAL)))
 
     def test_signature_parameter_equality(self):
         P = inspect.Parameter
@@ -2607,13 +2779,6 @@ class TestParameterObject(unittest.TestCase):
         self.assertEqual(p, P('foo', default=42,
                               kind=inspect.Parameter.KEYWORD_ONLY))
 
-    def test_signature_parameter_unhashable(self):
-        p = inspect.Parameter('foo', default=42,
-                              kind=inspect.Parameter.KEYWORD_ONLY)
-
-        with self.assertRaisesRegex(TypeError, 'unhashable type'):
-            hash(p)
-
     def test_signature_parameter_replace(self):
         p = inspect.Parameter('foo', default=42,
                               kind=inspect.Parameter.KEYWORD_ONLY)
@@ -2922,6 +3087,16 @@ class TestBoundArguments(unittest.TestCase):
         ba4 = inspect.signature(bar).bind(1)
         self.assertNotEqual(ba, ba4)
 
+    def test_signature_bound_arguments_pickle(self):
+        def foo(a, b, *, c:1={}, **kw) -> {42:'ham'}: pass
+        sig = inspect.signature(foo)
+        ba = sig.bind(20, 30, z={})
+
+        for ver in range(pickle.HIGHEST_PROTOCOL + 1):
+            with self.subTest(pickle_ver=ver):
+                ba_pickled = pickle.loads(pickle.dumps(ba, ver))
+                self.assertEqual(ba, ba_pickled)
+
 
 class TestSignaturePrivateHelpers(unittest.TestCase):
     def test_signature_get_bound_param(self):
diff --git a/Lib/test/test_io.py b/Lib/test/test_io.py
index a424f760f7..c867502e9b 100644
--- a/Lib/test/test_io.py
+++ b/Lib/test/test_io.py
@@ -44,10 +44,6 @@ try:
     import threading
 except ImportError:
     threading = None
-try:
-    import fcntl
-except ImportError:
-    fcntl = None
 
 def _default_chunk_size():
     """Get the default TextIOWrapper chunk size"""
@@ -367,8 +363,8 @@ class IOTest(unittest.TestCase):
 
     def test_open_handles_NUL_chars(self):
         fn_with_NUL = 'foo\0bar'
-        self.assertRaises(TypeError, self.open, fn_with_NUL, 'w')
-        self.assertRaises(TypeError, self.open, bytes(fn_with_NUL, 'ascii'), 'w')
+        self.assertRaises(ValueError, self.open, fn_with_NUL, 'w')
+        self.assertRaises(ValueError, self.open, bytes(fn_with_NUL, 'ascii'), 'w')
 
     def test_raw_file_io(self):
         with self.open(support.TESTFN, "wb", buffering=0) as f:
@@ -780,7 +776,7 @@ class CommonBufferedTests:
     def test_repr(self):
         raw = self.MockRawIO()
         b = self.tp(raw)
-        clsname = "%s.%s" % (self.tp.__module__, self.tp.__name__)
+        clsname = "%s.%s" % (self.tp.__module__, self.tp.__qualname__)
         self.assertEqual(repr(b), "<%s>" % clsname)
         raw.name = "dummy"
         self.assertEqual(repr(b), "<%s name='dummy'>" % clsname)
@@ -945,6 +941,71 @@ class BufferedReaderTest(unittest.TestCase, CommonBufferedTests):
         self.assertEqual(bufio.readinto(b), 1)
         self.assertEqual(b, b"cb")
 
+    def test_readinto1(self):
+        buffer_size = 10
+        rawio = self.MockRawIO((b"abc", b"de", b"fgh", b"jkl"))
+        bufio = self.tp(rawio, buffer_size=buffer_size)
+        b = bytearray(2)
+        self.assertEqual(bufio.peek(3), b'abc')
+        self.assertEqual(rawio._reads, 1)
+        self.assertEqual(bufio.readinto1(b), 2)
+        self.assertEqual(b, b"ab")
+        self.assertEqual(rawio._reads, 1)
+        self.assertEqual(bufio.readinto1(b), 1)
+        self.assertEqual(b[:1], b"c")
+        self.assertEqual(rawio._reads, 1)
+        self.assertEqual(bufio.readinto1(b), 2)
+        self.assertEqual(b, b"de")
+        self.assertEqual(rawio._reads, 2)
+        b = bytearray(2*buffer_size)
+        self.assertEqual(bufio.peek(3), b'fgh')
+        self.assertEqual(rawio._reads, 3)
+        self.assertEqual(bufio.readinto1(b), 6)
+        self.assertEqual(b[:6], b"fghjkl")
+        self.assertEqual(rawio._reads, 4)
+
+    def test_readinto_array(self):
+        buffer_size = 60
+        data = b"a" * 26
+        rawio = self.MockRawIO((data,))
+        bufio = self.tp(rawio, buffer_size=buffer_size)
+
+        # Create an array with element size > 1 byte
+        b = array.array('i', b'x' * 32)
+        assert len(b) != 16
+
+        # Read into it. We should get as many *bytes* as we can fit into b
+        # (which is more than the number of elements)
+        n = bufio.readinto(b)
+        self.assertGreater(n, len(b))
+
+        # Check that old contents of b are preserved
+        bm = memoryview(b).cast('B')
+        self.assertLess(n, len(bm))
+        self.assertEqual(bm[:n], data[:n])
+        self.assertEqual(bm[n:], b'x' * (len(bm[n:])))
+
+    def test_readinto1_array(self):
+        buffer_size = 60
+        data = b"a" * 26
+        rawio = self.MockRawIO((data,))
+        bufio = self.tp(rawio, buffer_size=buffer_size)
+
+        # Create an array with element size > 1 byte
+        b = array.array('i', b'x' * 32)
+        assert len(b) != 16
+
+        # Read into it. We should get as many *bytes* as we can fit into b
+        # (which is more than the number of elements)
+        n = bufio.readinto1(b)
+        self.assertGreater(n, len(b))
+
+        # Check that old contents of b are preserved
+        bm = memoryview(b).cast('B')
+        self.assertLess(n, len(bm))
+        self.assertEqual(bm[:n], data[:n])
+        self.assertEqual(bm[n:], b'x' * (len(bm[n:])))
+
     def test_readlines(self):
         def bufio():
             rawio = self.MockRawIO((b"abc\n", b"d\n", b"ef"))
@@ -2795,6 +2856,17 @@ class TextIOWrapperTest(unittest.TestCase):
         self.assertFalse(err)
         self.assertEqual("ok", out.decode().strip())
 
+    def test_read_byteslike(self):
+        r = MemviewBytesIO(b'Just some random string\n')
+        t = self.TextIOWrapper(r, 'utf-8')
+
+        # TextIOwrapper will not read the full string, because
+        # we truncate it to a multiple of the native int size
+        # so that we can construct a more complex memoryview.
+        bytes_val =  _to_memoryview(r.getvalue()).tobytes()
+
+        self.assertEqual(t.read(200), bytes_val.decode('utf-8'))
+
     def test_issue22849(self):
         class F(object):
             def readable(self): return True
@@ -2811,6 +2883,25 @@ class TextIOWrapperTest(unittest.TestCase):
         t = self.TextIOWrapper(F(), encoding='utf-8')
 
 
+class MemviewBytesIO(io.BytesIO):
+    '''A BytesIO object whose read method returns memoryviews
+       rather than bytes'''
+
+    def read1(self, len_):
+        return _to_memoryview(super().read1(len_))
+
+    def read(self, len_):
+        return _to_memoryview(super().read(len_))
+
+def _to_memoryview(buf):
+    '''Convert bytes-object *buf* to a non-trivial memoryview'''
+
+    arr = array.array('i')
+    idx = len(buf) - len(buf) % arr.itemsize
+    arr.frombytes(buf[:idx])
+    return memoryview(arr)
+
+
 class CTextIOWrapperTest(TextIOWrapperTest):
     io = io
     shutdown_error = "RuntimeError: could not find io module state"
@@ -3057,6 +3148,8 @@ class MiscIOTest(unittest.TestCase):
                 self.assertRaises(ValueError, f.readall)
             if hasattr(f, "readinto"):
                 self.assertRaises(ValueError, f.readinto, bytearray(1024))
+            if hasattr(f, "readinto1"):
+                self.assertRaises(ValueError, f.readinto1, bytearray(1024))
             self.assertRaises(ValueError, f.readline)
             self.assertRaises(ValueError, f.readlines)
             self.assertRaises(ValueError, f.seek, 0)
@@ -3170,26 +3263,20 @@ class MiscIOTest(unittest.TestCase):
                 with self.open(support.TESTFN, **kwargs) as f:
                     self.assertRaises(TypeError, pickle.dumps, f, protocol)
 
-    @unittest.skipUnless(fcntl, 'fcntl required for this test')
     def test_nonblock_pipe_write_bigbuf(self):
         self._test_nonblock_pipe_write(16*1024)
 
-    @unittest.skipUnless(fcntl, 'fcntl required for this test')
     def test_nonblock_pipe_write_smallbuf(self):
         self._test_nonblock_pipe_write(1024)
 
-    def _set_non_blocking(self, fd):
-        flags = fcntl.fcntl(fd, fcntl.F_GETFL)
-        self.assertNotEqual(flags, -1)
-        res = fcntl.fcntl(fd, fcntl.F_SETFL, flags | os.O_NONBLOCK)
-        self.assertEqual(res, 0)
-
+    @unittest.skipUnless(hasattr(os, 'set_blocking'),
+                         'os.set_blocking() required for this test')
     def _test_nonblock_pipe_write(self, bufsize):
         sent = []
         received = []
         r, w = os.pipe()
-        self._set_non_blocking(r)
-        self._set_non_blocking(w)
+        os.set_blocking(r, False)
+        os.set_blocking(w, False)
 
         # To exercise all code paths in the C implementation we need
         # to play with buffer sizes.  For instance, if we choose a
diff --git a/Lib/test/test_ipaddress.py b/Lib/test/test_ipaddress.py
index bfb569950f..e985329117 100644
--- a/Lib/test/test_ipaddress.py
+++ b/Lib/test/test_ipaddress.py
@@ -9,6 +9,7 @@ import re
 import contextlib
 import functools
 import operator
+import pickle
 import ipaddress
 
 
@@ -83,6 +84,13 @@ class CommonTestMixin:
         self.assertRaises(TypeError, hex, self.factory(1))
         self.assertRaises(TypeError, bytes, self.factory(1))
 
+    def pickle_test(self, addr):
+        for proto in range(pickle.HIGHEST_PROTOCOL + 1):
+            with self.subTest(proto=proto):
+                x = self.factory(addr)
+                y = pickle.loads(pickle.dumps(x, proto))
+                self.assertEqual(y, x)
+
 
 class CommonTestMixin_v4(CommonTestMixin):
 
@@ -248,6 +256,9 @@ class AddressTestCase_v4(BaseTestCase, CommonTestMixin_v4):
         assertBadOctet("257.0.0.0", 257)
         assertBadOctet("192.168.0.999", 999)
 
+    def test_pickle(self):
+        self.pickle_test('192.0.2.1')
+
 
 class AddressTestCase_v6(BaseTestCase, CommonTestMixin_v6):
     factory = ipaddress.IPv6Address
@@ -380,6 +391,9 @@ class AddressTestCase_v6(BaseTestCase, CommonTestMixin_v6):
         assertBadPart("02001:db8::", "02001")
         assertBadPart('2001:888888::1', "888888")
 
+    def test_pickle(self):
+        self.pickle_test('2001:db8::')
+
 
 class NetmaskTestMixin_v4(CommonTestMixin_v4):
     """Input validation on interfaces and networks is very similar"""
@@ -443,6 +457,11 @@ class NetmaskTestMixin_v4(CommonTestMixin_v4):
         assertBadNetmask("1.1.1.1", "pudding")
         assertBadNetmask("1.1.1.1", "::")
 
+    def test_pickle(self):
+        self.pickle_test('192.0.2.0/27')
+        self.pickle_test('192.0.2.0/31')  # IPV4LENGTH - 1
+        self.pickle_test('192.0.2.0')     # IPV4LENGTH
+
 
 class InterfaceTestCase_v4(BaseTestCase, NetmaskTestMixin_v4):
     factory = ipaddress.IPv4Interface
@@ -501,6 +520,11 @@ class NetmaskTestMixin_v6(CommonTestMixin_v6):
         assertBadNetmask("::1", "pudding")
         assertBadNetmask("::", "::")
 
+    def test_pickle(self):
+        self.pickle_test('2001:db8::1000/124')
+        self.pickle_test('2001:db8::1000/127')  # IPV6LENGTH - 1
+        self.pickle_test('2001:db8::1000')      # IPV6LENGTH
+
 
 class InterfaceTestCase_v6(BaseTestCase, NetmaskTestMixin_v6):
     factory = ipaddress.IPv6Interface
@@ -670,6 +694,119 @@ class IpaddrUnitTest(unittest.TestCase):
         self.assertEqual("IPv6Interface('::1/128')",
                          repr(ipaddress.IPv6Interface('::1')))
 
+    # issue #16531: constructing IPv4Network from a (address, mask) tuple
+    def testIPv4Tuple(self):
+        # /32
+        ip = ipaddress.IPv4Address('192.0.2.1')
+        net = ipaddress.IPv4Network('192.0.2.1/32')
+        self.assertEqual(ipaddress.IPv4Network(('192.0.2.1', 32)), net)
+        self.assertEqual(ipaddress.IPv4Network((ip, 32)), net)
+        self.assertEqual(ipaddress.IPv4Network((3221225985, 32)), net)
+        self.assertEqual(ipaddress.IPv4Network(('192.0.2.1',
+                                                '255.255.255.255')), net)
+        self.assertEqual(ipaddress.IPv4Network((ip,
+                                                '255.255.255.255')), net)
+        self.assertEqual(ipaddress.IPv4Network((3221225985,
+                                                '255.255.255.255')), net)
+        # strict=True and host bits set
+        with self.assertRaises(ValueError):
+            ipaddress.IPv4Network(('192.0.2.1', 24))
+        with self.assertRaises(ValueError):
+            ipaddress.IPv4Network((ip, 24))
+        with self.assertRaises(ValueError):
+            ipaddress.IPv4Network((3221225985, 24))
+        with self.assertRaises(ValueError):
+            ipaddress.IPv4Network(('192.0.2.1', '255.255.255.0'))
+        with self.assertRaises(ValueError):
+            ipaddress.IPv4Network((ip, '255.255.255.0'))
+        with self.assertRaises(ValueError):
+            ipaddress.IPv4Network((3221225985, '255.255.255.0'))
+        # strict=False and host bits set
+        net = ipaddress.IPv4Network('192.0.2.0/24')
+        self.assertEqual(ipaddress.IPv4Network(('192.0.2.1', 24),
+                                               strict=False), net)
+        self.assertEqual(ipaddress.IPv4Network((ip, 24),
+                                               strict=False), net)
+        self.assertEqual(ipaddress.IPv4Network((3221225985, 24),
+                                               strict=False), net)
+        self.assertEqual(ipaddress.IPv4Network(('192.0.2.1',
+                                                '255.255.255.0'),
+                                               strict=False), net)
+        self.assertEqual(ipaddress.IPv4Network((ip,
+                                                '255.255.255.0'),
+                                               strict=False), net)
+        self.assertEqual(ipaddress.IPv4Network((3221225985,
+                                                '255.255.255.0'),
+                                               strict=False), net)
+
+        # /24
+        ip = ipaddress.IPv4Address('192.0.2.0')
+        net = ipaddress.IPv4Network('192.0.2.0/24')
+        self.assertEqual(ipaddress.IPv4Network(('192.0.2.0',
+                                                '255.255.255.0')), net)
+        self.assertEqual(ipaddress.IPv4Network((ip,
+                                                '255.255.255.0')), net)
+        self.assertEqual(ipaddress.IPv4Network((3221225984,
+                                                '255.255.255.0')), net)
+        self.assertEqual(ipaddress.IPv4Network(('192.0.2.0', 24)), net)
+        self.assertEqual(ipaddress.IPv4Network((ip, 24)), net)
+        self.assertEqual(ipaddress.IPv4Network((3221225984, 24)), net)
+
+        self.assertEqual(ipaddress.IPv4Interface(('192.0.2.1', 24)),
+                         ipaddress.IPv4Interface('192.0.2.1/24'))
+        self.assertEqual(ipaddress.IPv4Interface((3221225985, 24)),
+                         ipaddress.IPv4Interface('192.0.2.1/24'))
+
+    # issue #16531: constructing IPv6Network from a (address, mask) tuple
+    def testIPv6Tuple(self):
+        # /128
+        ip = ipaddress.IPv6Address('2001:db8::')
+        net = ipaddress.IPv6Network('2001:db8::/128')
+        self.assertEqual(ipaddress.IPv6Network(('2001:db8::', '128')),
+                         net)
+        self.assertEqual(ipaddress.IPv6Network(
+                (42540766411282592856903984951653826560, 128)),
+                         net)
+        self.assertEqual(ipaddress.IPv6Network((ip, '128')),
+                         net)
+        ip = ipaddress.IPv6Address('2001:db8::')
+        net = ipaddress.IPv6Network('2001:db8::/96')
+        self.assertEqual(ipaddress.IPv6Network(('2001:db8::', '96')),
+                         net)
+        self.assertEqual(ipaddress.IPv6Network(
+                (42540766411282592856903984951653826560, 96)),
+                         net)
+        self.assertEqual(ipaddress.IPv6Network((ip, '96')),
+                         net)
+
+        # strict=True and host bits set
+        ip = ipaddress.IPv6Address('2001:db8::1')
+        with self.assertRaises(ValueError):
+            ipaddress.IPv6Network(('2001:db8::1', 96))
+        with self.assertRaises(ValueError):
+            ipaddress.IPv6Network((
+                42540766411282592856903984951653826561, 96))
+        with self.assertRaises(ValueError):
+            ipaddress.IPv6Network((ip, 96))
+        # strict=False and host bits set
+        net = ipaddress.IPv6Network('2001:db8::/96')
+        self.assertEqual(ipaddress.IPv6Network(('2001:db8::1', 96),
+                                               strict=False),
+                         net)
+        self.assertEqual(ipaddress.IPv6Network(
+                             (42540766411282592856903984951653826561, 96),
+                             strict=False),
+                         net)
+        self.assertEqual(ipaddress.IPv6Network((ip, 96), strict=False),
+                         net)
+
+        # /96
+        self.assertEqual(ipaddress.IPv6Interface(('2001:db8::1', '96')),
+                         ipaddress.IPv6Interface('2001:db8::1/96'))
+        self.assertEqual(ipaddress.IPv6Interface(
+                (42540766411282592856903984951653826561, '96')),
+                         ipaddress.IPv6Interface('2001:db8::1/96'))
+
     # issue57
     def testAddressIntMath(self):
         self.assertEqual(ipaddress.IPv4Address('1.1.1.1') + 255,
@@ -690,20 +827,18 @@ class IpaddrUnitTest(unittest.TestCase):
                           2 ** ipaddress.IPV6LENGTH)
 
     def testInternals(self):
-        first, last = ipaddress._find_address_range([
-            ipaddress.IPv4Address('10.10.10.10'),
-            ipaddress.IPv4Address('10.10.10.12')])
-        self.assertEqual(first, last)
+        ip1 = ipaddress.IPv4Address('10.10.10.10')
+        ip2 = ipaddress.IPv4Address('10.10.10.11')
+        ip3 = ipaddress.IPv4Address('10.10.10.12')
+        self.assertEqual(list(ipaddress._find_address_range([ip1])),
+                         [(ip1, ip1)])
+        self.assertEqual(list(ipaddress._find_address_range([ip1, ip3])),
+                         [(ip1, ip1), (ip3, ip3)])
+        self.assertEqual(list(ipaddress._find_address_range([ip1, ip2, ip3])),
+                         [(ip1, ip3)])
         self.assertEqual(128, ipaddress._count_righthand_zero_bits(0, 128))
         self.assertEqual("IPv4Network('1.2.3.0/24')", repr(self.ipv4_network))
 
-    def testMissingAddressVersion(self):
-        class Broken(ipaddress._BaseAddress):
-            pass
-        broken = Broken('127.0.0.1')
-        with self.assertRaisesRegex(NotImplementedError, "Broken.*version"):
-            broken.version
-
     def testMissingNetworkVersion(self):
         class Broken(ipaddress._BaseNetwork):
             pass
@@ -1635,6 +1770,14 @@ class IpaddrUnitTest(unittest.TestCase):
                          addr3.exploded)
         self.assertEqual('192.168.178.1', addr4.exploded)
 
+    def testReversePointer(self):
+        addr1 = ipaddress.IPv4Address('127.0.0.1')
+        addr2 = ipaddress.IPv6Address('2001:db8::1')
+        self.assertEqual('1.0.0.127.in-addr.arpa', addr1.reverse_pointer)
+        self.assertEqual('1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.8.' +
+                         'b.d.0.1.0.0.2.ip6.arpa',
+                         addr2.reverse_pointer)
+
     def testIntRepresentation(self):
         self.assertEqual(16909060, int(self.ipv4_address))
         self.assertEqual(42540616829182469433547762482097946625,
diff --git a/Lib/test/test_itertools.py b/Lib/test/test_itertools.py
index 244598b752..6a0130e6e0 100644
--- a/Lib/test/test_itertools.py
+++ b/Lib/test/test_itertools.py
@@ -1856,8 +1856,6 @@ class RegressionTests(unittest.TestCase):
             hist.append(3)
             yield 2
             hist.append(4)
-            if x:
-                raise StopIteration
 
         hist = []
         self.assertRaises(AssertionError, list, chain(gen1(), gen2(False)))
diff --git a/Lib/test/test_json/__init__.py b/Lib/test/test_json/__init__.py
index 2cf1032f35..0807e6fb4f 100644
--- a/Lib/test/test_json/__init__.py
+++ b/Lib/test/test_json/__init__.py
@@ -9,12 +9,15 @@ from test import support
 # import json with and without accelerations
 cjson = support.import_fresh_module('json', fresh=['_json'])
 pyjson = support.import_fresh_module('json', blocked=['_json'])
+# JSONDecodeError is cached inside the _json module
+cjson.JSONDecodeError = cjson.decoder.JSONDecodeError = json.JSONDecodeError
 
 # create two base classes that will be used by the other tests
 class PyTest(unittest.TestCase):
     json = pyjson
     loads = staticmethod(pyjson.loads)
     dumps = staticmethod(pyjson.dumps)
+    JSONDecodeError = staticmethod(pyjson.JSONDecodeError)
 
 @unittest.skipUnless(cjson, 'requires _json')
 class CTest(unittest.TestCase):
@@ -22,6 +25,7 @@ class CTest(unittest.TestCase):
         json = cjson
         loads = staticmethod(cjson.loads)
         dumps = staticmethod(cjson.dumps)
+        JSONDecodeError = staticmethod(cjson.JSONDecodeError)
 
 # test PyTest and CTest checking if the functions come from the right module
 class TestPyTest(PyTest):
diff --git a/Lib/test/test_json/test_decode.py b/Lib/test/test_json/test_decode.py
index 591b2e253d..cc83b45e8b 100644
--- a/Lib/test/test_json/test_decode.py
+++ b/Lib/test/test_json/test_decode.py
@@ -63,12 +63,12 @@ class TestDecode:
     def test_extra_data(self):
         s = '[1, 2, 3]5'
         msg = 'Extra data'
-        self.assertRaisesRegex(ValueError, msg, self.loads, s)
+        self.assertRaisesRegex(self.JSONDecodeError, msg, self.loads, s)
 
     def test_invalid_escape(self):
         s = '["abc\\y"]'
         msg = 'escape'
-        self.assertRaisesRegex(ValueError, msg, self.loads, s)
+        self.assertRaisesRegex(self.JSONDecodeError, msg, self.loads, s)
 
     def test_invalid_input_type(self):
         msg = 'the JSON object must be str'
@@ -80,10 +80,10 @@ class TestDecode:
     def test_string_with_utf8_bom(self):
         # see #18958
         bom_json = "[1,2,3]".encode('utf-8-sig').decode('utf-8')
-        with self.assertRaises(ValueError) as cm:
+        with self.assertRaises(self.JSONDecodeError) as cm:
             self.loads(bom_json)
         self.assertIn('BOM', str(cm.exception))
-        with self.assertRaises(ValueError) as cm:
+        with self.assertRaises(self.JSONDecodeError) as cm:
             self.json.load(StringIO(bom_json))
         self.assertIn('BOM', str(cm.exception))
         # make sure that the BOM is not detected in the middle of a string
diff --git a/Lib/test/test_json/test_encode_basestring_ascii.py b/Lib/test/test_json/test_encode_basestring_ascii.py
index 2122da17fd..4bbc6c7148 100644
--- a/Lib/test/test_json/test_encode_basestring_ascii.py
+++ b/Lib/test/test_json/test_encode_basestring_ascii.py
@@ -12,9 +12,6 @@ CASES = [
     (' s p a c e d ', '" s p a c e d "'),
     ('\U0001d120', '"\\ud834\\udd20"'),
     ('\u03b1\u03a9', '"\\u03b1\\u03a9"'),
-    ('\u03b1\u03a9', '"\\u03b1\\u03a9"'),
-    ('\u03b1\u03a9', '"\\u03b1\\u03a9"'),
-    ('\u03b1\u03a9', '"\\u03b1\\u03a9"'),
     ("`1~!@#$%^&*()_+-={':[,]}|;.</>?", '"`1~!@#$%^&*()_+-={\':[,]}|;.</>?"'),
     ('\x08\x0c\n\r\t', '"\\b\\f\\n\\r\\t"'),
     ('\u0123\u4567\u89ab\ucdef\uabcd\uef4a', '"\\u0123\\u4567\\u89ab\\ucdef\\uabcd\\uef4a"'),
diff --git a/Lib/test/test_json/test_fail.py b/Lib/test/test_json/test_fail.py
index 7caafdbddd..95ff5b8d1e 100644
--- a/Lib/test/test_json/test_fail.py
+++ b/Lib/test/test_json/test_fail.py
@@ -87,7 +87,7 @@ class TestFail:
                 continue
             try:
                 self.loads(doc)
-            except ValueError:
+            except self.JSONDecodeError:
                 pass
             else:
                 self.fail("Expected failure for fail{0}.json: {1!r}".format(idx, doc))
@@ -124,10 +124,16 @@ class TestFail:
             ('"spam', 'Unterminated string starting at', 0),
         ]
         for data, msg, idx in test_cases:
-            self.assertRaisesRegex(ValueError,
-                r'^{0}: line 1 column {1} \(char {2}\)'.format(
-                    re.escape(msg), idx + 1, idx),
-                self.loads, data)
+            with self.assertRaises(self.JSONDecodeError) as cm:
+                self.loads(data)
+            err = cm.exception
+            self.assertEqual(err.msg, msg)
+            self.assertEqual(err.pos, idx)
+            self.assertEqual(err.lineno, 1)
+            self.assertEqual(err.colno, idx + 1)
+            self.assertEqual(str(err),
+                             '%s: line 1 column %d (char %d)' %
+                             (msg, idx + 1, idx))
 
     def test_unexpected_data(self):
         test_cases = [
@@ -154,10 +160,16 @@ class TestFail:
             ('{"spam":42,}', 'Expecting property name enclosed in double quotes', 11),
         ]
         for data, msg, idx in test_cases:
-            self.assertRaisesRegex(ValueError,
-                r'^{0}: line 1 column {1} \(char {2}\)'.format(
-                    re.escape(msg), idx + 1, idx),
-                self.loads, data)
+            with self.assertRaises(self.JSONDecodeError) as cm:
+                self.loads(data)
+            err = cm.exception
+            self.assertEqual(err.msg, msg)
+            self.assertEqual(err.pos, idx)
+            self.assertEqual(err.lineno, 1)
+            self.assertEqual(err.colno, idx + 1)
+            self.assertEqual(str(err),
+                             '%s: line 1 column %d (char %d)' %
+                             (msg, idx + 1, idx))
 
     def test_extra_data(self):
         test_cases = [
@@ -171,11 +183,16 @@ class TestFail:
             ('"spam",42', 'Extra data', 6),
         ]
         for data, msg, idx in test_cases:
-            self.assertRaisesRegex(ValueError,
-                r'^{0}: line 1 column {1} - line 1 column {2}'
-                r' \(char {3} - {4}\)'.format(
-                    re.escape(msg), idx + 1, len(data) + 1, idx, len(data)),
-                self.loads, data)
+            with self.assertRaises(self.JSONDecodeError) as cm:
+                self.loads(data)
+            err = cm.exception
+            self.assertEqual(err.msg, msg)
+            self.assertEqual(err.pos, idx)
+            self.assertEqual(err.lineno, 1)
+            self.assertEqual(err.colno, idx + 1)
+            self.assertEqual(str(err),
+                             '%s: line 1 column %d (char %d)' %
+                             (msg, idx + 1, idx))
 
     def test_linecol(self):
         test_cases = [
@@ -185,10 +202,16 @@ class TestFail:
             ('\n  \n\n     !', 4, 6, 10),
         ]
         for data, line, col, idx in test_cases:
-            self.assertRaisesRegex(ValueError,
-                r'^Expecting value: line {0} column {1}'
-                r' \(char {2}\)$'.format(line, col, idx),
-                self.loads, data)
+            with self.assertRaises(self.JSONDecodeError) as cm:
+                self.loads(data)
+            err = cm.exception
+            self.assertEqual(err.msg, 'Expecting value')
+            self.assertEqual(err.pos, idx)
+            self.assertEqual(err.lineno, line)
+            self.assertEqual(err.colno, col)
+            self.assertEqual(str(err),
+                             'Expecting value: line %s column %d (char %d)' %
+                             (line, col, idx))
 
 class TestPyFail(TestFail, PyTest): pass
 class TestCFail(TestFail, CTest): pass
diff --git a/Lib/test/test_json/test_scanstring.py b/Lib/test/test_json/test_scanstring.py
index 07f4358100..2d3ee8a8bf 100644
--- a/Lib/test/test_json/test_scanstring.py
+++ b/Lib/test/test_json/test_scanstring.py
@@ -129,7 +129,7 @@ class TestScanstring:
             '"\\ud834\\u0X20"',
         ]
         for s in bad_escapes:
-            with self.assertRaises(ValueError, msg=s):
+            with self.assertRaises(self.JSONDecodeError, msg=s):
                 scanstring(s, 1, True)
 
     def test_overflow(self):
diff --git a/Lib/test/test_json/test_tool.py b/Lib/test/test_json/test_tool.py
index 0c39e56837..bd63e2b311 100644
--- a/Lib/test/test_json/test_tool.py
+++ b/Lib/test/test_json/test_tool.py
@@ -6,6 +6,7 @@ import subprocess
 from test import support
 from test.script_helper import assert_python_ok
 
+
 class TestTool(unittest.TestCase):
     data = """
 
@@ -15,7 +16,7 @@ class TestTool(unittest.TestCase):
             :"yes"}  ]
            """
 
-    expect = textwrap.dedent("""\
+    expect_without_sort_keys = textwrap.dedent("""\
     [
         [
             "blorpie"
@@ -37,6 +38,28 @@ class TestTool(unittest.TestCase):
     ]
     """)
 
+    expect = textwrap.dedent("""\
+    [
+        [
+            "blorpie"
+        ],
+        [
+            "whoops"
+        ],
+        [],
+        "d-shtaeou",
+        "d-nthiouh",
+        "i-vhbjkhnth",
+        {
+            "nifty": 87
+        },
+        {
+            "morefield": false,
+            "field": "yes"
+        }
+    ]
+    """)
+
     def test_stdin_stdout(self):
         with subprocess.Popen(
                 (sys.executable, '-m', 'json.tool'),
@@ -55,6 +78,7 @@ class TestTool(unittest.TestCase):
     def test_infile_stdout(self):
         infile = self._create_infile()
         rc, out, err = assert_python_ok('-m', 'json.tool', infile)
+        self.assertEqual(rc, 0)
         self.assertEqual(out.splitlines(), self.expect.encode().splitlines())
         self.assertEqual(err, b'')
 
@@ -65,5 +89,20 @@ class TestTool(unittest.TestCase):
         self.addCleanup(os.remove, outfile)
         with open(outfile, "r") as fp:
             self.assertEqual(fp.read(), self.expect)
+        self.assertEqual(rc, 0)
         self.assertEqual(out, b'')
         self.assertEqual(err, b'')
+
+    def test_help_flag(self):
+        rc, out, err = assert_python_ok('-m', 'json.tool', '-h')
+        self.assertEqual(rc, 0)
+        self.assertTrue(out.startswith(b'usage: '))
+        self.assertEqual(err, b'')
+
+    def test_sort_keys_flag(self):
+        infile = self._create_infile()
+        rc, out, err = assert_python_ok('-m', 'json.tool', '--sort-keys', infile)
+        self.assertEqual(rc, 0)
+        self.assertEqual(out.splitlines(),
+                         self.expect_without_sort_keys.encode().splitlines())
+        self.assertEqual(err, b'')
diff --git a/Lib/test/test_kqueue.py b/Lib/test/test_kqueue.py
index f79bd8978c..2585ca6810 100644
--- a/Lib/test/test_kqueue.py
+++ b/Lib/test/test_kqueue.py
@@ -114,7 +114,7 @@ class TestKQueue(unittest.TestCase):
     def test_queue_event(self):
         serverSocket = socket.socket()
         serverSocket.bind(('127.0.0.1', 0))
-        serverSocket.listen(1)
+        serverSocket.listen()
         client = socket.socket()
         client.setblocking(False)
         try:
diff --git a/Lib/test/test_locale.py b/Lib/test/test_locale.py
index 9369a2531e..fae2c3dabb 100644
--- a/Lib/test/test_locale.py
+++ b/Lib/test/test_locale.py
@@ -524,5 +524,59 @@ class TestMiscellaneous(unittest.TestCase):
             locale.setlocale(locale.LC_ALL, (b'not', b'valid'))
 
 
+class BaseDelocalizeTest(BaseLocalizedTest):
+
+    def _test_delocalize(self, value, out):
+        self.assertEqual(locale.delocalize(value), out)
+
+    def _test_atof(self, value, out):
+        self.assertEqual(locale.atof(value), out)
+
+    def _test_atoi(self, value, out):
+        self.assertEqual(locale.atoi(value), out)
+
+
+class TestEnUSDelocalize(EnUSCookedTest, BaseDelocalizeTest):
+
+    def test_delocalize(self):
+        self._test_delocalize('50000.00', '50000.00')
+        self._test_delocalize('50,000.00', '50000.00')
+
+    def test_atof(self):
+        self._test_atof('50000.00', 50000.)
+        self._test_atof('50,000.00', 50000.)
+
+    def test_atoi(self):
+        self._test_atoi('50000', 50000)
+        self._test_atoi('50,000', 50000)
+
+
+class TestCDelocalizeTest(CCookedTest, BaseDelocalizeTest):
+
+    def test_delocalize(self):
+        self._test_delocalize('50000.00', '50000.00')
+
+    def test_atof(self):
+        self._test_atof('50000.00', 50000.)
+
+    def test_atoi(self):
+        self._test_atoi('50000', 50000)
+
+
+class TestfrFRDelocalizeTest(FrFRCookedTest, BaseDelocalizeTest):
+
+    def test_delocalize(self):
+        self._test_delocalize('50000,00', '50000.00')
+        self._test_delocalize('50 000,00', '50000.00')
+
+    def test_atof(self):
+        self._test_atof('50000,00', 50000.)
+        self._test_atof('50 000,00', 50000.)
+
+    def test_atoi(self):
+        self._test_atoi('50000', 50000)
+        self._test_atoi('50 000', 50000)
+
+
 if __name__ == '__main__':
     unittest.main()
diff --git a/Lib/test/test_logging.py b/Lib/test/test_logging.py
index 54be2176a8..c8b6a98032 100644
--- a/Lib/test/test_logging.py
+++ b/Lib/test/test_logging.py
@@ -1,4 +1,4 @@
-# Copyright 2001-2013 by Vinay Sajip. All Rights Reserved.
+# Copyright 2001-2014 by Vinay Sajip. All Rights Reserved.
 #
 # Permission to use, copy, modify, and distribute this software and its
 # documentation for any purpose and without fee is hereby granted,
@@ -16,7 +16,7 @@
 
 """Test harness for the logging module. Run all tests.
 
-Copyright (C) 2001-2013 Vinay Sajip. All Rights Reserved.
+Copyright (C) 2001-2014 Vinay Sajip. All Rights Reserved.
 """
 
 import logging
@@ -34,14 +34,12 @@ import os
 import queue
 import random
 import re
-import select
 import socket
 import struct
 import sys
 import tempfile
 from test.script_helper import assert_python_ok
-from test.support import (captured_stdout, run_with_locale, run_unittest,
-                          patch, requires_zlib, TestHandler, Matcher, HOST)
+from test import support
 import textwrap
 import time
 import unittest
@@ -51,16 +49,12 @@ try:
     import threading
     # The following imports are needed only for tests which
     # require threading
-    import asynchat
     import asyncore
-    import errno
     from http.server import HTTPServer, BaseHTTPRequestHandler
     import smtpd
     from urllib.parse import urlparse, parse_qs
     from socketserver import (ThreadingUDPServer, DatagramRequestHandler,
-                              ThreadingTCPServer, StreamRequestHandler,
-                              ThreadingUnixStreamServer,
-                              ThreadingUnixDatagramServer)
+                              ThreadingTCPServer, StreamRequestHandler)
 except ImportError:
     threading = None
 try:
@@ -645,22 +639,23 @@ class StreamHandlerTest(BaseTest):
         h = TestStreamHandler(BadStream())
         r = logging.makeLogRecord({})
         old_raise = logging.raiseExceptions
-        old_stderr = sys.stderr
+
         try:
             h.handle(r)
             self.assertIs(h.error_record, r)
+
             h = logging.StreamHandler(BadStream())
-            sys.stderr = sio = io.StringIO()
-            h.handle(r)
-            self.assertIn('\nRuntimeError: deliberate mistake\n',
-                          sio.getvalue())
+            with support.captured_stderr() as stderr:
+                h.handle(r)
+                msg = '\nRuntimeError: deliberate mistake\n'
+                self.assertIn(msg, stderr.getvalue())
+
             logging.raiseExceptions = False
-            sys.stderr = sio = io.StringIO()
-            h.handle(r)
-            self.assertEqual('', sio.getvalue())
+            with support.captured_stderr() as stderr:
+                h.handle(r)
+                self.assertEqual('', stderr.getvalue())
         finally:
             logging.raiseExceptions = old_raise
-            sys.stderr = old_stderr
 
 # -- The following section could be moved into a server_helper.py module
 # -- if it proves to be of wider utility than just test_logging
@@ -688,7 +683,8 @@ if threading:
         """
 
         def __init__(self, addr, handler, poll_interval, sockmap):
-            smtpd.SMTPServer.__init__(self, addr, None, map=sockmap)
+            smtpd.SMTPServer.__init__(self, addr, None, map=sockmap,
+                                      decode_data=True)
             self.port = self.socket.getsockname()[1]
             self._handler = handler
             self._thread = None
@@ -930,10 +926,10 @@ class SMTPHandlerTest(BaseTest):
     TIMEOUT = 8.0
     def test_basic(self):
         sockmap = {}
-        server = TestSMTPServer((HOST, 0), self.process_message, 0.001,
+        server = TestSMTPServer((support.HOST, 0), self.process_message, 0.001,
                                 sockmap)
         server.start()
-        addr = (HOST, server.port)
+        addr = (support.HOST, server.port)
         h = logging.handlers.SMTPHandler(addr, 'me', 'you', 'Log',
                                          timeout=self.TIMEOUT)
         self.assertEqual(h.toaddrs, ['you'])
@@ -1249,7 +1245,7 @@ class ConfigFileTest(BaseTest):
 
     def test_config0_ok(self):
         # A simple config file which overrides the default settings.
-        with captured_stdout() as output:
+        with support.captured_stdout() as output:
             self.apply_config(self.config0)
             logger = logging.getLogger()
             # Won't output anything
@@ -1264,7 +1260,7 @@ class ConfigFileTest(BaseTest):
 
     def test_config0_using_cp_ok(self):
         # A simple config file which overrides the default settings.
-        with captured_stdout() as output:
+        with support.captured_stdout() as output:
             file = io.StringIO(textwrap.dedent(self.config0))
             cp = configparser.ConfigParser()
             cp.read_file(file)
@@ -1282,7 +1278,7 @@ class ConfigFileTest(BaseTest):
 
     def test_config1_ok(self, config=config1):
         # A config file defining a sub-parser as well.
-        with captured_stdout() as output:
+        with support.captured_stdout() as output:
             self.apply_config(config)
             logger = logging.getLogger("compiler.parser")
             # Both will output a message
@@ -1305,7 +1301,7 @@ class ConfigFileTest(BaseTest):
 
     def test_config4_ok(self):
         # A config file specifying a custom formatter class.
-        with captured_stdout() as output:
+        with support.captured_stdout() as output:
             self.apply_config(self.config4)
             logger = logging.getLogger()
             try:
@@ -1325,7 +1321,7 @@ class ConfigFileTest(BaseTest):
         self.test_config1_ok(config=self.config6)
 
     def test_config7_ok(self):
-        with captured_stdout() as output:
+        with support.captured_stdout() as output:
             self.apply_config(self.config1a)
             logger = logging.getLogger("compiler.parser")
             # See issue #11424. compiler-hyphenated sorts
@@ -1345,7 +1341,7 @@ class ConfigFileTest(BaseTest):
             ], stream=output)
             # Original logger output is empty.
             self.assert_log_lines([])
-        with captured_stdout() as output:
+        with support.captured_stdout() as output:
             self.apply_config(self.config7)
             logger = logging.getLogger("compiler.parser")
             self.assertFalse(logger.disabled)
@@ -2492,7 +2488,7 @@ class ConfigDictTest(BaseTest):
 
     def test_config0_ok(self):
         # A simple config which overrides the default settings.
-        with captured_stdout() as output:
+        with support.captured_stdout() as output:
             self.apply_config(self.config0)
             logger = logging.getLogger()
             # Won't output anything
@@ -2507,7 +2503,7 @@ class ConfigDictTest(BaseTest):
 
     def test_config1_ok(self, config=config1):
         # A config defining a sub-parser as well.
-        with captured_stdout() as output:
+        with support.captured_stdout() as output:
             self.apply_config(config)
             logger = logging.getLogger("compiler.parser")
             # Both will output a message
@@ -2538,7 +2534,7 @@ class ConfigDictTest(BaseTest):
 
     def test_config4_ok(self):
         # A config specifying a custom formatter class.
-        with captured_stdout() as output:
+        with support.captured_stdout() as output:
             self.apply_config(self.config4)
             #logger = logging.getLogger()
             try:
@@ -2553,7 +2549,7 @@ class ConfigDictTest(BaseTest):
 
     def test_config4a_ok(self):
         # A config specifying a custom formatter class.
-        with captured_stdout() as output:
+        with support.captured_stdout() as output:
             self.apply_config(self.config4a)
             #logger = logging.getLogger()
             try:
@@ -2573,7 +2569,7 @@ class ConfigDictTest(BaseTest):
         self.assertRaises(Exception, self.apply_config, self.config6)
 
     def test_config7_ok(self):
-        with captured_stdout() as output:
+        with support.captured_stdout() as output:
             self.apply_config(self.config1)
             logger = logging.getLogger("compiler.parser")
             # Both will output a message
@@ -2585,7 +2581,7 @@ class ConfigDictTest(BaseTest):
             ], stream=output)
             # Original logger output is empty.
             self.assert_log_lines([])
-        with captured_stdout() as output:
+        with support.captured_stdout() as output:
             self.apply_config(self.config7)
             logger = logging.getLogger("compiler.parser")
             self.assertTrue(logger.disabled)
@@ -2602,7 +2598,7 @@ class ConfigDictTest(BaseTest):
 
     #Same as test_config_7_ok but don't disable old loggers.
     def test_config_8_ok(self):
-        with captured_stdout() as output:
+        with support.captured_stdout() as output:
             self.apply_config(self.config1)
             logger = logging.getLogger("compiler.parser")
             # All will output a message
@@ -2614,7 +2610,7 @@ class ConfigDictTest(BaseTest):
             ], stream=output)
             # Original logger output is empty.
             self.assert_log_lines([])
-        with captured_stdout() as output:
+        with support.captured_stdout() as output:
             self.apply_config(self.config8)
             logger = logging.getLogger("compiler.parser")
             self.assertFalse(logger.disabled)
@@ -2635,7 +2631,7 @@ class ConfigDictTest(BaseTest):
             self.assert_log_lines([])
 
     def test_config_8a_ok(self):
-        with captured_stdout() as output:
+        with support.captured_stdout() as output:
             self.apply_config(self.config1a)
             logger = logging.getLogger("compiler.parser")
             # See issue #11424. compiler-hyphenated sorts
@@ -2655,7 +2651,7 @@ class ConfigDictTest(BaseTest):
             ], stream=output)
             # Original logger output is empty.
             self.assert_log_lines([])
-        with captured_stdout() as output:
+        with support.captured_stdout() as output:
             self.apply_config(self.config8a)
             logger = logging.getLogger("compiler.parser")
             self.assertFalse(logger.disabled)
@@ -2678,7 +2674,7 @@ class ConfigDictTest(BaseTest):
             self.assert_log_lines([])
 
     def test_config_9_ok(self):
-        with captured_stdout() as output:
+        with support.captured_stdout() as output:
             self.apply_config(self.config9)
             logger = logging.getLogger("compiler.parser")
             #Nothing will be output since both handler and logger are set to WARNING
@@ -2696,7 +2692,7 @@ class ConfigDictTest(BaseTest):
             ], stream=output)
 
     def test_config_10_ok(self):
-        with captured_stdout() as output:
+        with support.captured_stdout() as output:
             self.apply_config(self.config10)
             logger = logging.getLogger("compiler.parser")
             logger.warning(self.next_message())
@@ -2724,7 +2720,7 @@ class ConfigDictTest(BaseTest):
         self.assertRaises(Exception, self.apply_config, self.config13)
 
     def test_config14_ok(self):
-        with captured_stdout() as output:
+        with support.captured_stdout() as output:
             self.apply_config(self.config14)
             h = logging._handlers['hand1']
             self.assertEqual(h.foo, 'bar')
@@ -2763,7 +2759,7 @@ class ConfigDictTest(BaseTest):
 
     @unittest.skipUnless(threading, 'Threading required for this test.')
     def test_listen_config_10_ok(self):
-        with captured_stdout() as output:
+        with support.captured_stdout() as output:
             self.setup_via_listener(json.dumps(self.config10))
             logger = logging.getLogger("compiler.parser")
             logger.warning(self.next_message())
@@ -2783,7 +2779,7 @@ class ConfigDictTest(BaseTest):
 
     @unittest.skipUnless(threading, 'Threading required for this test.')
     def test_listen_config_1_ok(self):
-        with captured_stdout() as output:
+        with support.captured_stdout() as output:
             self.setup_via_listener(textwrap.dedent(ConfigFileTest.config1))
             logger = logging.getLogger("compiler.parser")
             # Both will output a message
@@ -2810,7 +2806,7 @@ class ConfigDictTest(BaseTest):
         # First, specify a verification function that will fail.
         # We expect to see no output, since our configuration
         # never took effect.
-        with captured_stdout() as output:
+        with support.captured_stdout() as output:
             self.setup_via_listener(to_send, verify_fail)
             # Both will output a message
             logger.info(self.next_message())
@@ -2825,7 +2821,7 @@ class ConfigDictTest(BaseTest):
         # Now, perform no verification. Our configuration
         # should take effect.
 
-        with captured_stdout() as output:
+        with support.captured_stdout() as output:
             self.setup_via_listener(to_send)    # no verify callable specified
             logger = logging.getLogger("compiler.parser")
             # Both will output a message
@@ -2843,7 +2839,7 @@ class ConfigDictTest(BaseTest):
 
         # Now, perform verification which transforms the bytes.
 
-        with captured_stdout() as output:
+        with support.captured_stdout() as output:
             self.setup_via_listener(to_send[::-1], verify_reverse)
             logger = logging.getLogger("compiler.parser")
             # Both will output a message
@@ -2998,7 +2994,7 @@ class QueueHandlerTest(BaseTest):
     @unittest.skipUnless(hasattr(logging.handlers, 'QueueListener'),
                          'logging.handlers.QueueListener required for this test')
     def test_queue_listener(self):
-        handler = TestHandler(Matcher())
+        handler = support.TestHandler(support.Matcher())
         listener = logging.handlers.QueueListener(self.queue, handler)
         listener.start()
         try:
@@ -3010,6 +3006,25 @@ class QueueHandlerTest(BaseTest):
         self.assertTrue(handler.matches(levelno=logging.WARNING, message='1'))
         self.assertTrue(handler.matches(levelno=logging.ERROR, message='2'))
         self.assertTrue(handler.matches(levelno=logging.CRITICAL, message='3'))
+        handler.close()
+
+        # Now test with respect_handler_level set
+
+        handler = support.TestHandler(support.Matcher())
+        handler.setLevel(logging.CRITICAL)
+        listener = logging.handlers.QueueListener(self.queue, handler,
+                                                  respect_handler_level=True)
+        listener.start()
+        try:
+            self.que_logger.warning(self.next_message())
+            self.que_logger.error(self.next_message())
+            self.que_logger.critical(self.next_message())
+        finally:
+            listener.stop()
+        self.assertFalse(handler.matches(levelno=logging.WARNING, message='4'))
+        self.assertFalse(handler.matches(levelno=logging.ERROR, message='5'))
+        self.assertTrue(handler.matches(levelno=logging.CRITICAL, message='6'))
+
 
 ZERO = datetime.timedelta(0)
 
@@ -3166,32 +3181,35 @@ class LastResortTest(BaseTest):
         # Test the last resort handler
         root = self.root_logger
         root.removeHandler(self.root_hdlr)
-        old_stderr = sys.stderr
         old_lastresort = logging.lastResort
         old_raise_exceptions = logging.raiseExceptions
+
         try:
-            sys.stderr = sio = io.StringIO()
-            root.debug('This should not appear')
-            self.assertEqual(sio.getvalue(), '')
-            root.warning('This is your final chance!')
-            self.assertEqual(sio.getvalue(), 'This is your final chance!\n')
-            #No handlers and no last resort, so 'No handlers' message
+            with support.captured_stderr() as stderr:
+                root.debug('This should not appear')
+                self.assertEqual(stderr.getvalue(), '')
+                root.warning('Final chance!')
+                self.assertEqual(stderr.getvalue(), 'Final chance!\n')
+
+            # No handlers and no last resort, so 'No handlers' message
             logging.lastResort = None
-            sys.stderr = sio = io.StringIO()
-            root.warning('This is your final chance!')
-            self.assertEqual(sio.getvalue(), 'No handlers could be found for logger "root"\n')
+            with support.captured_stderr() as stderr:
+                root.warning('Final chance!')
+                msg = 'No handlers could be found for logger "root"\n'
+                self.assertEqual(stderr.getvalue(), msg)
+
             # 'No handlers' message only printed once
-            sys.stderr = sio = io.StringIO()
-            root.warning('This is your final chance!')
-            self.assertEqual(sio.getvalue(), '')
+            with support.captured_stderr() as stderr:
+                root.warning('Final chance!')
+                self.assertEqual(stderr.getvalue(), '')
+
+            # If raiseExceptions is False, no message is printed
             root.manager.emittedNoHandlerWarning = False
-            #If raiseExceptions is False, no message is printed
             logging.raiseExceptions = False
-            sys.stderr = sio = io.StringIO()
-            root.warning('This is your final chance!')
-            self.assertEqual(sio.getvalue(), '')
+            with support.captured_stderr() as stderr:
+                root.warning('Final chance!')
+                self.assertEqual(stderr.getvalue(), '')
         finally:
-            sys.stderr = old_stderr
             root.addHandler(self.root_hdlr)
             logging.lastResort = old_lastresort
             logging.raiseExceptions = old_raise_exceptions
@@ -3322,8 +3340,8 @@ class ModuleLevelMiscTest(BaseTest):
 
     def _test_log(self, method, level=None):
         called = []
-        patch(self, logging, 'basicConfig',
-              lambda *a, **kw: called.append((a, kw)))
+        support.patch(self, logging, 'basicConfig',
+                      lambda *a, **kw: called.append((a, kw)))
 
         recording = RecordingHandler()
         logging.root.addHandler(recording)
@@ -3494,7 +3512,7 @@ class BasicConfigTest(unittest.TestCase):
         self.assertEqual(logging.root.level, self.original_logging_level)
 
     def test_strformatstyle(self):
-        with captured_stdout() as output:
+        with support.captured_stdout() as output:
             logging.basicConfig(stream=sys.stdout, style="{")
             logging.error("Log an error")
             sys.stdout.seek(0)
@@ -3502,7 +3520,7 @@ class BasicConfigTest(unittest.TestCase):
                 "ERROR:root:Log an error")
 
     def test_stringtemplatestyle(self):
-        with captured_stdout() as output:
+        with support.captured_stdout() as output:
             logging.basicConfig(stream=sys.stdout, style="$")
             logging.error("Log an error")
             sys.stdout.seek(0)
@@ -3619,7 +3637,7 @@ class BasicConfigTest(unittest.TestCase):
             self.addCleanup(logging.root.setLevel, old_level)
             called.append((a, kw))
 
-        patch(self, logging, 'basicConfig', my_basic_config)
+        support.patch(self, logging, 'basicConfig', my_basic_config)
 
         log_method = getattr(logging, method)
         if level is not None:
@@ -3685,6 +3703,19 @@ class LoggerAdapterTest(unittest.TestCase):
         self.assertEqual(record.exc_info,
                          (exc.__class__, exc, exc.__traceback__))
 
+    def test_exception_excinfo(self):
+        try:
+            1 / 0
+        except ZeroDivisionError as e:
+            exc = e
+
+        self.adapter.exception('exc_info test', exc_info=exc)
+
+        self.assertEqual(len(self.recording.records), 1)
+        record = self.recording.records[0]
+        self.assertEqual(record.exc_info,
+                         (exc.__class__, exc, exc.__traceback__))
+
     def test_critical(self):
         msg = 'critical test! %r'
         self.adapter.critical(msg, self.recording)
@@ -3759,8 +3790,8 @@ class LoggerTest(BaseTest):
 
     def test_find_caller_with_stack_info(self):
         called = []
-        patch(self, logging.traceback, 'print_stack',
-              lambda f, file: called.append(file.getvalue()))
+        support.patch(self, logging.traceback, 'print_stack',
+                      lambda f, file: called.append(file.getvalue()))
 
         self.logger.findCaller(stack_info=True)
 
@@ -3897,7 +3928,7 @@ class RotatingFileHandlerTest(BaseFileTest):
         self.assertFalse(os.path.exists(namer(self.fn + ".3")))
         rh.close()
 
-    @requires_zlib
+    @support.requires_zlib
     def test_rotator(self):
         def namer(name):
             return name + ".gz"
@@ -4130,22 +4161,20 @@ class NTEventLogHandlerTest(BaseTest):
 # Set the locale to the platform-dependent default.  I have no idea
 # why the test does this, but in any case we save the current locale
 # first and restore it at the end.
-@run_with_locale('LC_ALL', '')
+@support.run_with_locale('LC_ALL', '')
 def test_main():
-    run_unittest(BuiltinLevelsTest, BasicFilterTest,
-                 CustomLevelsAndFiltersTest, HandlerTest, MemoryHandlerTest,
-                 ConfigFileTest, SocketHandlerTest, DatagramHandlerTest,
-                 MemoryTest, EncodingTest, WarningsTest, ConfigDictTest,
-                 ManagerTest, FormatterTest, BufferingFormatterTest,
-                 StreamHandlerTest, LogRecordFactoryTest, ChildLoggerTest,
-                 QueueHandlerTest, ShutdownTest, ModuleLevelMiscTest,
-                 BasicConfigTest, LoggerAdapterTest, LoggerTest,
-                 SMTPHandlerTest, FileHandlerTest, RotatingFileHandlerTest,
-                 LastResortTest, LogRecordTest, ExceptionTest,
-                 SysLogHandlerTest, HTTPHandlerTest, NTEventLogHandlerTest,
-                 TimedRotatingFileHandlerTest, UnixSocketHandlerTest,
-                 UnixDatagramHandlerTest, UnixSysLogHandlerTest
-                )
+    support.run_unittest(
+        BuiltinLevelsTest, BasicFilterTest, CustomLevelsAndFiltersTest,
+        HandlerTest, MemoryHandlerTest, ConfigFileTest, SocketHandlerTest,
+        DatagramHandlerTest, MemoryTest, EncodingTest, WarningsTest,
+        ConfigDictTest, ManagerTest, FormatterTest, BufferingFormatterTest,
+        StreamHandlerTest, LogRecordFactoryTest, ChildLoggerTest,
+        QueueHandlerTest, ShutdownTest, ModuleLevelMiscTest, BasicConfigTest,
+        LoggerAdapterTest, LoggerTest, SMTPHandlerTest, FileHandlerTest,
+        RotatingFileHandlerTest,  LastResortTest, LogRecordTest,
+        ExceptionTest, SysLogHandlerTest, HTTPHandlerTest,
+        NTEventLogHandlerTest, TimedRotatingFileHandlerTest,
+        UnixSocketHandlerTest, UnixDatagramHandlerTest, UnixSysLogHandlerTest)
 
 if __name__ == "__main__":
     test_main()
diff --git a/Lib/test/test_long.py b/Lib/test/test_long.py
index 5f14795649..57847d88f7 100644
--- a/Lib/test/test_long.py
+++ b/Lib/test/test_long.py
@@ -599,8 +599,6 @@ class LongTest(unittest.TestCase):
                 return (x > y) - (x < y)
             def __eq__(self, other):
                 return self._cmp__(other) == 0
-            def __ne__(self, other):
-                return self._cmp__(other) != 0
             def __ge__(self, other):
                 return self._cmp__(other) >= 0
             def __gt__(self, other):
diff --git a/Lib/test/test_lzma.py b/Lib/test/test_lzma.py
index 07fadbde11..cded28c9b2 100644
--- a/Lib/test/test_lzma.py
+++ b/Lib/test/test_lzma.py
@@ -135,6 +135,97 @@ class CompressorDecompressorTestCase(unittest.TestCase):
         self.assertTrue(lzd.eof)
         self.assertEqual(lzd.unused_data, b"")
 
+    def test_decompressor_chunks_maxsize(self):
+        lzd = LZMADecompressor()
+        max_length = 100
+        out = []
+
+        # Feed first half the input
+        len_ = len(COMPRESSED_XZ) // 2
+        out.append(lzd.decompress(COMPRESSED_XZ[:len_],
+                                  max_length=max_length))
+        self.assertFalse(lzd.needs_input)
+        self.assertEqual(len(out[-1]), max_length)
+
+        # Retrieve more data without providing more input
+        out.append(lzd.decompress(b'', max_length=max_length))
+        self.assertFalse(lzd.needs_input)
+        self.assertEqual(len(out[-1]), max_length)
+
+        # Retrieve more data while providing more input
+        out.append(lzd.decompress(COMPRESSED_XZ[len_:],
+                                  max_length=max_length))
+        self.assertLessEqual(len(out[-1]), max_length)
+
+        # Retrieve remaining uncompressed data
+        while not lzd.eof:
+            out.append(lzd.decompress(b'', max_length=max_length))
+            self.assertLessEqual(len(out[-1]), max_length)
+
+        out = b"".join(out)
+        self.assertEqual(out, INPUT)
+        self.assertEqual(lzd.check, lzma.CHECK_CRC64)
+        self.assertEqual(lzd.unused_data, b"")
+
+    def test_decompressor_inputbuf_1(self):
+        # Test reusing input buffer after moving existing
+        # contents to beginning
+        lzd = LZMADecompressor()
+        out = []
+
+        # Create input buffer and fill it
+        self.assertEqual(lzd.decompress(COMPRESSED_XZ[:100],
+                                        max_length=0), b'')
+
+        # Retrieve some results, freeing capacity at beginning
+        # of input buffer
+        out.append(lzd.decompress(b'', 2))
+
+        # Add more data that fits into input buffer after
+        # moving existing data to beginning
+        out.append(lzd.decompress(COMPRESSED_XZ[100:105], 15))
+
+        # Decompress rest of data
+        out.append(lzd.decompress(COMPRESSED_XZ[105:]))
+        self.assertEqual(b''.join(out), INPUT)
+
+    def test_decompressor_inputbuf_2(self):
+        # Test reusing input buffer by appending data at the
+        # end right away
+        lzd = LZMADecompressor()
+        out = []
+
+        # Create input buffer and empty it
+        self.assertEqual(lzd.decompress(COMPRESSED_XZ[:200],
+                                        max_length=0), b'')
+        out.append(lzd.decompress(b''))
+
+        # Fill buffer with new data
+        out.append(lzd.decompress(COMPRESSED_XZ[200:280], 2))
+
+        # Append some more data, not enough to require resize
+        out.append(lzd.decompress(COMPRESSED_XZ[280:300], 2))
+
+        # Decompress rest of data
+        out.append(lzd.decompress(COMPRESSED_XZ[300:]))
+        self.assertEqual(b''.join(out), INPUT)
+
+    def test_decompressor_inputbuf_3(self):
+        # Test reusing input buffer after extending it
+
+        lzd = LZMADecompressor()
+        out = []
+
+        # Create almost full input buffer
+        out.append(lzd.decompress(COMPRESSED_XZ[:200], 5))
+
+        # Add even more data to it, requiring resize
+        out.append(lzd.decompress(COMPRESSED_XZ[200:300], 5))
+
+        # Decompress rest of data
+        out.append(lzd.decompress(COMPRESSED_XZ[300:]))
+        self.assertEqual(b''.join(out), INPUT)
+
     def test_decompressor_unused_data(self):
         lzd = LZMADecompressor()
         extra = b"fooblibar"
diff --git a/Lib/test/test_macpath.py b/Lib/test/test_macpath.py
index 22f84919bb..80bec7a799 100644
--- a/Lib/test/test_macpath.py
+++ b/Lib/test/test_macpath.py
@@ -142,6 +142,8 @@ class MacPathTestCase(unittest.TestCase):
 class MacCommonTest(test_genericpath.CommonTest, unittest.TestCase):
     pathmodule = macpath
 
+    test_relpath_errors = None
+
 
 if __name__ == "__main__":
     unittest.main()
diff --git a/Lib/test/test_marshal.py b/Lib/test/test_marshal.py
index 903e12c8c4..c7def9a599 100644
--- a/Lib/test/test_marshal.py
+++ b/Lib/test/test_marshal.py
@@ -193,7 +193,7 @@ class BugsTestCase(unittest.TestCase):
         head = last = []
         # The max stack depth should match the value in Python/marshal.c.
         if os.name == 'nt' and hasattr(sys, 'gettotalrefcount'):
-            MAX_MARSHAL_STACK_DEPTH = 1500
+            MAX_MARSHAL_STACK_DEPTH = 1000
         else:
             MAX_MARSHAL_STACK_DEPTH = 2000
         for i in range(MAX_MARSHAL_STACK_DEPTH - 2):
diff --git a/Lib/test/test_math.py b/Lib/test/test_math.py
index 48f84ba732..023dea9465 100644
--- a/Lib/test/test_math.py
+++ b/Lib/test/test_math.py
@@ -422,9 +422,17 @@ class MathTests(unittest.TestCase):
             self.assertEqual(math.factorial(i), py_factorial(i))
         self.assertRaises(ValueError, math.factorial, -1)
         self.assertRaises(ValueError, math.factorial, -1.0)
+        self.assertRaises(ValueError, math.factorial, -10**100)
+        self.assertRaises(ValueError, math.factorial, -1e100)
         self.assertRaises(ValueError, math.factorial, math.pi)
-        self.assertRaises(OverflowError, math.factorial, sys.maxsize+1)
-        self.assertRaises(OverflowError, math.factorial, 10e100)
+
+    # Other implementations may place different upper bounds.
+    @support.cpython_only
+    def testFactorialHugeInputs(self):
+        # Currently raises ValueError for inputs that are too large
+        # to fit into a C long.
+        self.assertRaises(OverflowError, math.factorial, 10**100)
+        self.assertRaises(OverflowError, math.factorial, 1e100)
 
     def testFloor(self):
         self.assertRaises(TypeError, math.floor)
@@ -975,6 +983,17 @@ class MathTests(unittest.TestCase):
         self.assertFalse(math.isinf(0.))
         self.assertFalse(math.isinf(1.))
 
+    @requires_IEEE_754
+    def test_nan_constant(self):
+        self.assertTrue(math.isnan(math.nan))
+
+    @requires_IEEE_754
+    def test_inf_constant(self):
+        self.assertTrue(math.isinf(math.inf))
+        self.assertGreater(math.inf, 0.0)
+        self.assertEqual(math.inf, float("inf"))
+        self.assertEqual(-math.inf, float("-inf"))
+
     # RED_FLAG 16-Oct-2000 Tim
     # While 2.0 is more consistent about exceptions than previous releases, it
     # still fails this part of the test on some platforms.  For now, we only
diff --git a/Lib/test/test_memoryio.py b/Lib/test/test_memoryio.py
index 9a2461dea6..77749e78e8 100644
--- a/Lib/test/test_memoryio.py
+++ b/Lib/test/test_memoryio.py
@@ -9,6 +9,7 @@ from test import support
 import io
 import _pyio as pyio
 import pickle
+import sys
 
 class MemorySeekTestMixin:
 
@@ -717,12 +718,56 @@ class CBytesIOTest(PyBytesIOTest):
 
     @support.cpython_only
     def test_sizeof(self):
-        basesize = support.calcobjsize('P2nN2Pn')
+        basesize = support.calcobjsize('P2n2Pn')
         check = self.check_sizeof
         self.assertEqual(object.__sizeof__(io.BytesIO()), basesize)
         check(io.BytesIO(), basesize )
-        check(io.BytesIO(b'a'), basesize + 1 + 1 )
-        check(io.BytesIO(b'a' * 1000), basesize + 1000 + 1 )
+        check(io.BytesIO(b'a' * 1000), basesize + sys.getsizeof(b'a' * 1000))
+
+    # Various tests of copy-on-write behaviour for BytesIO.
+
+    def _test_cow_mutation(self, mutation):
+        # Common code for all BytesIO copy-on-write mutation tests.
+        imm = b' ' * 1024
+        old_rc = sys.getrefcount(imm)
+        memio = self.ioclass(imm)
+        self.assertEqual(sys.getrefcount(imm), old_rc + 1)
+        mutation(memio)
+        self.assertEqual(sys.getrefcount(imm), old_rc)
+
+    @support.cpython_only
+    def test_cow_truncate(self):
+        # Ensure truncate causes a copy.
+        def mutation(memio):
+            memio.truncate(1)
+        self._test_cow_mutation(mutation)
+
+    @support.cpython_only
+    def test_cow_write(self):
+        # Ensure write that would not cause a resize still results in a copy.
+        def mutation(memio):
+            memio.seek(0)
+            memio.write(b'foo')
+        self._test_cow_mutation(mutation)
+
+    @support.cpython_only
+    def test_cow_setstate(self):
+        # __setstate__ should cause buffer to be released.
+        memio = self.ioclass(b'foooooo')
+        state = memio.__getstate__()
+        def mutation(memio):
+            memio.__setstate__(state)
+        self._test_cow_mutation(mutation)
+
+    @support.cpython_only
+    def test_cow_mutable(self):
+        # BytesIO should accept only Bytes for copy-on-write sharing, since
+        # arbitrary buffer-exporting objects like bytearray() aren't guaranteed
+        # to be immutable.
+        ba = bytearray(1024)
+        old_rc = sys.getrefcount(ba)
+        memio = self.ioclass(ba)
+        self.assertEqual(sys.getrefcount(ba), old_rc)
 
 class CStringIOTest(PyStringIOTest):
     ioclass = io.StringIO
diff --git a/Lib/test/test_memoryview.py b/Lib/test/test_memoryview.py
index 4bc31330b7..e9bd9fdf82 100644
--- a/Lib/test/test_memoryview.py
+++ b/Lib/test/test_memoryview.py
@@ -369,12 +369,12 @@ class AbstractMemoryTests:
         d = memoryview(b)
 
         del b
- 
+
         self.assertEqual(c[0], 256)
         self.assertEqual(d[0], 256)
         self.assertEqual(c.format, "H")
         self.assertEqual(d.format, "H")
- 
+
         _ = m.cast('I')
         self.assertEqual(c[0], 256)
         self.assertEqual(d[0], 256)
diff --git a/Lib/test/test_module.py b/Lib/test/test_module.py
index 1230293670..9da3536333 100644
--- a/Lib/test/test_module.py
+++ b/Lib/test/test_module.py
@@ -30,6 +30,22 @@ class ModuleTests(unittest.TestCase):
             pass
         self.assertEqual(foo.__doc__, ModuleType.__doc__)
 
+    def test_unintialized_missing_getattr(self):
+        # Issue 8297
+        # test the text in the AttributeError of an uninitialized module
+        foo = ModuleType.__new__(ModuleType)
+        self.assertRaisesRegex(
+                AttributeError, "module has no attribute 'not_here'",
+                getattr, foo, "not_here")
+
+    def test_missing_getattr(self):
+        # Issue 8297
+        # test the text in the AttributeError
+        foo = ModuleType("foo")
+        self.assertRaisesRegex(
+                AttributeError, "module 'foo' has no attribute 'not_here'",
+                getattr, foo, "not_here")
+
     def test_no_docstring(self):
         # Regularly initialized module, no docstring
         foo = ModuleType("foo")
@@ -211,6 +227,14 @@ a = A(destroyed)"""
             b"len = len",
             b"shutil.rmtree = rmtree"})
 
+    def test_descriptor_errors_propogate(self):
+        class Descr:
+            def __get__(self, o, t):
+                raise RuntimeError
+        class M(ModuleType):
+            melon = Descr()
+        self.assertRaises(RuntimeError, getattr, M("mymod"), "melon")
+
     # frozen and namespace module reprs are tested in importlib.
 
 
diff --git a/Lib/test/test_operator.py b/Lib/test/test_operator.py
index ab58a98365..1bd0391ee2 100644
--- a/Lib/test/test_operator.py
+++ b/Lib/test/test_operator.py
@@ -203,6 +203,15 @@ class OperatorTestCase:
         self.assertRaises(TypeError, operator.mul, None, None)
         self.assertTrue(operator.mul(5, 2) == 10)
 
+    def test_matmul(self):
+        operator = self.module
+        self.assertRaises(TypeError, operator.matmul)
+        self.assertRaises(TypeError, operator.matmul, 42, 42)
+        class M:
+            def __matmul__(self, other):
+                return other - 1
+        self.assertEqual(M() @ 42, 41)
+
     def test_neg(self):
         operator = self.module
         self.assertRaises(TypeError, operator.neg)
@@ -416,6 +425,7 @@ class OperatorTestCase:
             def __ilshift__  (self, other): return "ilshift"
             def __imod__     (self, other): return "imod"
             def __imul__     (self, other): return "imul"
+            def __imatmul__  (self, other): return "imatmul"
             def __ior__      (self, other): return "ior"
             def __ipow__     (self, other): return "ipow"
             def __irshift__  (self, other): return "irshift"
@@ -430,6 +440,7 @@ class OperatorTestCase:
         self.assertEqual(operator.ilshift  (c, 5), "ilshift")
         self.assertEqual(operator.imod     (c, 5), "imod")
         self.assertEqual(operator.imul     (c, 5), "imul")
+        self.assertEqual(operator.imatmul  (c, 5), "imatmul")
         self.assertEqual(operator.ior      (c, 5), "ior")
         self.assertEqual(operator.ipow     (c, 5), "ipow")
         self.assertEqual(operator.irshift  (c, 5), "irshift")
diff --git a/Lib/test/test_os.py b/Lib/test/test_os.py
index 152ba93576..afa7a4a1d1 100644
--- a/Lib/test/test_os.py
+++ b/Lib/test/test_os.py
@@ -4,6 +4,7 @@
 
 import os
 import errno
+import getpass
 import unittest
 import warnings
 import sys
@@ -40,9 +41,35 @@ try:
     import fcntl
 except ImportError:
     fcntl = None
+try:
+    import _winapi
+except ImportError:
+    _winapi = None
+try:
+    import grp
+    groups = [g.gr_gid for g in grp.getgrall() if getpass.getuser() in g.gr_mem]
+    if hasattr(os, 'getgid'):
+        process_gid = os.getgid()
+        if process_gid not in groups:
+            groups.append(process_gid)
+except ImportError:
+    groups = []
+try:
+    import pwd
+    all_users = [u.pw_uid for u in pwd.getpwall()]
+except ImportError:
+    all_users = []
+try:
+    from _testcapi import INT_MAX, PY_SSIZE_T_MAX
+except ImportError:
+    INT_MAX = PY_SSIZE_T_MAX = sys.maxsize
 
 from test.script_helper import assert_python_ok
 
+root_in_posix = False
+if hasattr(os, 'geteuid'):
+    root_in_posix = (os.geteuid() == 0)
+
 with warnings.catch_warnings():
     warnings.simplefilter("ignore", DeprecationWarning)
     os.stat_float_times(True)
@@ -116,6 +143,26 @@ class FileTests(unittest.TestCase):
             self.assertEqual(type(s), bytes)
             self.assertEqual(s, b"spam")
 
+    @support.cpython_only
+    # Skip the test on 32-bit platforms: the number of bytes must fit in a
+    # Py_ssize_t type
+    @unittest.skipUnless(INT_MAX < PY_SSIZE_T_MAX,
+                         "needs INT_MAX < PY_SSIZE_T_MAX")
+    @support.bigmemtest(size=INT_MAX + 10, memuse=1, dry_run=False)
+    def test_large_read(self, size):
+        with open(support.TESTFN, "wb") as fp:
+            fp.write(b'test')
+        self.addCleanup(support.unlink, support.TESTFN)
+
+        # Issue #21932: Make sure that os.read() does not raise an
+        # OverflowError for size larger than INT_MAX
+        with open(support.TESTFN, "rb") as fp:
+            data = os.read(fp.fileno(), size)
+
+        # The test does not try to read more than 2 GB at once because the
+        # operating system is free to return less bytes than requested.
+        self.assertEqual(data, b'test')
+
     def test_write(self):
         # os.write() accepts bytes- and buffer-like objects but not strings
         fd = os.open(support.TESTFN, os.O_CREAT | os.O_WRONLY)
@@ -533,6 +580,28 @@ class StatAttributeTests(unittest.TestCase):
             os.stat(r)
         self.assertEqual(ctx.exception.errno, errno.EBADF)
 
+    def check_file_attributes(self, result):
+        self.assertTrue(hasattr(result, 'st_file_attributes'))
+        self.assertTrue(isinstance(result.st_file_attributes, int))
+        self.assertTrue(0 <= result.st_file_attributes <= 0xFFFFFFFF)
+
+    @unittest.skipUnless(sys.platform == "win32",
+                         "st_file_attributes is Win32 specific")
+    def test_file_attributes(self):
+        # test file st_file_attributes (FILE_ATTRIBUTE_DIRECTORY not set)
+        result = os.stat(self.fname)
+        self.check_file_attributes(result)
+        self.assertEqual(
+            result.st_file_attributes & stat.FILE_ATTRIBUTE_DIRECTORY,
+            0)
+
+        # test directory st_file_attributes (FILE_ATTRIBUTE_DIRECTORY set)
+        result = os.stat(support.TESTFN)
+        self.check_file_attributes(result)
+        self.assertEqual(
+            result.st_file_attributes & stat.FILE_ATTRIBUTE_DIRECTORY,
+            stat.FILE_ATTRIBUTE_DIRECTORY)
+
 from test import mapping_tests
 
 class EnvironTests(mapping_tests.BasicTestMappingProtocol):
@@ -912,17 +981,6 @@ class MakedirTests(unittest.TestCase):
         os.makedirs(path, mode=mode, exist_ok=True)
         os.umask(old_mask)
 
-    @unittest.skipUnless(hasattr(os, 'chown'), 'test needs os.chown')
-    def test_chown_uid_gid_arguments_must_be_index(self):
-        stat = os.stat(support.TESTFN)
-        uid = stat.st_uid
-        gid = stat.st_gid
-        for value in (-1.0, -1j, decimal.Decimal(-1), fractions.Fraction(-2, 2)):
-            self.assertRaises(TypeError, os.chown, support.TESTFN, value, gid)
-            self.assertRaises(TypeError, os.chown, support.TESTFN, uid, value)
-        self.assertIsNone(os.chown(support.TESTFN, uid, gid))
-        self.assertIsNone(os.chown(support.TESTFN, -1, -1))
-
     def test_exist_ok_s_isgid_directory(self):
         path = os.path.join(support.TESTFN, 'dir1')
         S_ISGID = stat.S_ISGID
@@ -973,6 +1031,58 @@ class MakedirTests(unittest.TestCase):
         os.removedirs(path)
 
 
+@unittest.skipUnless(hasattr(os, 'chown'), "Test needs chown")
+class ChownFileTests(unittest.TestCase):
+
+    def setUpClass():
+        os.mkdir(support.TESTFN)
+
+    def test_chown_uid_gid_arguments_must_be_index(self):
+        stat = os.stat(support.TESTFN)
+        uid = stat.st_uid
+        gid = stat.st_gid
+        for value in (-1.0, -1j, decimal.Decimal(-1), fractions.Fraction(-2, 2)):
+            self.assertRaises(TypeError, os.chown, support.TESTFN, value, gid)
+            self.assertRaises(TypeError, os.chown, support.TESTFN, uid, value)
+        self.assertIsNone(os.chown(support.TESTFN, uid, gid))
+        self.assertIsNone(os.chown(support.TESTFN, -1, -1))
+
+    @unittest.skipUnless(len(groups) > 1, "test needs more than one group")
+    def test_chown(self):
+        gid_1, gid_2 = groups[:2]
+        uid = os.stat(support.TESTFN).st_uid
+        os.chown(support.TESTFN, uid, gid_1)
+        gid = os.stat(support.TESTFN).st_gid
+        self.assertEqual(gid, gid_1)
+        os.chown(support.TESTFN, uid, gid_2)
+        gid = os.stat(support.TESTFN).st_gid
+        self.assertEqual(gid, gid_2)
+
+    @unittest.skipUnless(root_in_posix and len(all_users) > 1,
+                         "test needs root privilege and more than one user")
+    def test_chown_with_root(self):
+        uid_1, uid_2 = all_users[:2]
+        gid = os.stat(support.TESTFN).st_gid
+        os.chown(support.TESTFN, uid_1, gid)
+        uid = os.stat(support.TESTFN).st_uid
+        self.assertEqual(uid, uid_1)
+        os.chown(support.TESTFN, uid_2, gid)
+        uid = os.stat(support.TESTFN).st_uid
+        self.assertEqual(uid, uid_2)
+
+    @unittest.skipUnless(not root_in_posix and len(all_users) > 1,
+                         "test needs non-root account and more than one user")
+    def test_chown_without_permission(self):
+        uid_1, uid_2 = all_users[:2]
+        gid = os.stat(support.TESTFN).st_gid
+        with self.assertRaises(PermissionError):
+            os.chown(support.TESTFN, uid_1, gid)
+            os.chown(support.TESTFN, uid_2, gid)
+
+    def tearDownClass():
+        os.rmdir(support.TESTFN)
+
+
 class RemoveDirsTests(unittest.TestCase):
     def setUp(self):
         os.makedirs(support.TESTFN)
@@ -1339,6 +1449,16 @@ class TestInvalidFD(unittest.TestCase):
     def test_writev(self):
         self.check(os.writev, [b'abc'])
 
+    def test_inheritable(self):
+        self.check(os.get_inheritable)
+        self.check(os.set_inheritable, True)
+
+    @unittest.skipUnless(hasattr(os, 'get_blocking'),
+                         'needs os.get_blocking() and os.set_blocking()')
+    def test_blocking(self):
+        self.check(os.get_blocking)
+        self.check(os.set_blocking, True)
+
 
 class LinkTests(unittest.TestCase):
     def setUp(self):
@@ -1786,6 +1906,37 @@ class Win32SymlinkTests(unittest.TestCase):
             shutil.rmtree(level1)
 
 
+@unittest.skipUnless(sys.platform == "win32", "Win32 specific tests")
+class Win32JunctionTests(unittest.TestCase):
+    junction = 'junctiontest'
+    junction_target = os.path.dirname(os.path.abspath(__file__))
+
+    def setUp(self):
+        assert os.path.exists(self.junction_target)
+        assert not os.path.exists(self.junction)
+
+    def tearDown(self):
+        if os.path.exists(self.junction):
+            # os.rmdir delegates to Windows' RemoveDirectoryW,
+            # which removes junction points safely.
+            os.rmdir(self.junction)
+
+    def test_create_junction(self):
+        _winapi.CreateJunction(self.junction_target, self.junction)
+        self.assertTrue(os.path.exists(self.junction))
+        self.assertTrue(os.path.isdir(self.junction))
+
+        # Junctions are not recognized as links.
+        self.assertFalse(os.path.islink(self.junction))
+
+    def test_unlink_removes_junction(self):
+        _winapi.CreateJunction(self.junction_target, self.junction)
+        self.assertTrue(os.path.exists(self.junction))
+
+        os.unlink(self.junction)
+        self.assertFalse(os.path.exists(self.junction))
+
+
 @support.skip_unless_symlink
 class NonLocalSymlinkTests(unittest.TestCase):
 
@@ -1992,11 +2143,13 @@ class TestSendfile(unittest.TestCase):
 
     @classmethod
     def setUpClass(cls):
+        cls.key = support.threading_setup()
         with open(support.TESTFN, "wb") as f:
             f.write(cls.DATA)
 
     @classmethod
     def tearDownClass(cls):
+        support.threading_cleanup(*cls.key)
         support.unlink(support.TESTFN)
 
     def setUp(self):
@@ -2523,41 +2676,27 @@ class FDInheritanceTests(unittest.TestCase):
         self.assertEqual(os.get_inheritable(slave_fd), False)
 
 
-@support.reap_threads
-def test_main():
-    support.run_unittest(
-        FileTests,
-        StatAttributeTests,
-        EnvironTests,
-        WalkTests,
-        FwalkTests,
-        MakedirTests,
-        DevNullTests,
-        URandomTests,
-        ExecTests,
-        Win32ErrorTests,
-        TestInvalidFD,
-        PosixUidGidTests,
-        Pep383Tests,
-        Win32KillTests,
-        Win32ListdirTests,
-        Win32SymlinkTests,
-        NonLocalSymlinkTests,
-        FSEncodingTests,
-        DeviceEncodingTests,
-        PidTests,
-        LoginTests,
-        LinkTests,
-        TestSendfile,
-        ProgramPriorityTests,
-        ExtendedAttributeTests,
-        Win32DeprecatedBytesAPI,
-        TermsizeTests,
-        OSErrorTests,
-        RemoveDirsTests,
-        CPUCountTests,
-        FDInheritanceTests,
-    )
+@unittest.skipUnless(hasattr(os, 'get_blocking'),
+                     'needs os.get_blocking() and os.set_blocking()')
+class BlockingTests(unittest.TestCase):
+    def test_blocking(self):
+        fd = os.open(__file__, os.O_RDONLY)
+        self.addCleanup(os.close, fd)
+        self.assertEqual(os.get_blocking(fd), True)
+
+        os.set_blocking(fd, False)
+        self.assertEqual(os.get_blocking(fd), False)
+
+        os.set_blocking(fd, True)
+        self.assertEqual(os.get_blocking(fd), True)
+
+
+
+class ExportsTests(unittest.TestCase):
+    def test_os_all(self):
+        self.assertIn('open', os.__all__)
+        self.assertIn('walk', os.__all__)
+
 
 if __name__ == "__main__":
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_pathlib.py b/Lib/test/test_pathlib.py
index 11420e2c17..1c53ab78ea 100644
--- a/Lib/test/test_pathlib.py
+++ b/Lib/test/test_pathlib.py
@@ -4,13 +4,10 @@ import os
 import errno
 import pathlib
 import pickle
-import shutil
 import socket
 import stat
-import sys
 import tempfile
 import unittest
-from contextlib import contextmanager
 
 from test import support
 TESTFN = support.TESTFN
@@ -747,7 +744,6 @@ class PureWindowsPathTest(_BasePurePathTest, unittest.TestCase):
         self.assertEqual(P('//Some/SHARE/a/B'), P('//somE/share/A/b'))
 
     def test_as_uri(self):
-        from urllib.parse import quote_from_bytes
         P = self.cls
         with self.assertRaises(ValueError):
             P('/a/b').as_uri()
@@ -1269,11 +1265,55 @@ class _BasePathTest(object):
         p = self.cls.cwd()
         self._test_cwd(p)
 
+    def _test_home(self, p):
+        q = self.cls(os.path.expanduser('~'))
+        self.assertEqual(p, q)
+        self.assertEqual(str(p), str(q))
+        self.assertIs(type(p), type(q))
+        self.assertTrue(p.is_absolute())
+
+    def test_home(self):
+        p = self.cls.home()
+        self._test_home(p)
+
+    def test_samefile(self):
+        fileA_path = os.path.join(BASE, 'fileA')
+        fileB_path = os.path.join(BASE, 'dirB', 'fileB')
+        p = self.cls(fileA_path)
+        pp = self.cls(fileA_path)
+        q = self.cls(fileB_path)
+        self.assertTrue(p.samefile(fileA_path))
+        self.assertTrue(p.samefile(pp))
+        self.assertFalse(p.samefile(fileB_path))
+        self.assertFalse(p.samefile(q))
+        # Test the non-existent file case
+        non_existent = os.path.join(BASE, 'foo')
+        r = self.cls(non_existent)
+        self.assertRaises(FileNotFoundError, p.samefile, r)
+        self.assertRaises(FileNotFoundError, p.samefile, non_existent)
+        self.assertRaises(FileNotFoundError, r.samefile, p)
+        self.assertRaises(FileNotFoundError, r.samefile, non_existent)
+        self.assertRaises(FileNotFoundError, r.samefile, r)
+        self.assertRaises(FileNotFoundError, r.samefile, non_existent)
+
     def test_empty_path(self):
         # The empty path points to '.'
         p = self.cls('')
         self.assertEqual(p.stat(), os.stat('.'))
 
+    def test_expanduser_common(self):
+        P = self.cls
+        p = P('~')
+        self.assertEqual(p.expanduser(), P(os.path.expanduser('~')))
+        p = P('foo')
+        self.assertEqual(p.expanduser(), p)
+        p = P('/~')
+        self.assertEqual(p.expanduser(), p)
+        p = P('../~')
+        self.assertEqual(p.expanduser(), p)
+        p = P(P('').absolute().anchor) / '~'
+        self.assertEqual(p.expanduser(), p)
+
     def test_exists(self):
         P = self.cls
         p = P(BASE)
@@ -1301,6 +1341,23 @@ class _BasePathTest(object):
             self.assertIsInstance(f, io.RawIOBase)
             self.assertEqual(f.read().strip(), b"this is file A")
 
+    def test_read_write_bytes(self):
+        p = self.cls(BASE)
+        (p / 'fileA').write_bytes(b'abcdefg')
+        self.assertEqual((p / 'fileA').read_bytes(), b'abcdefg')
+        # check that trying to write str does not truncate the file
+        self.assertRaises(TypeError, (p / 'fileA').write_bytes, 'somestr')
+        self.assertEqual((p / 'fileA').read_bytes(), b'abcdefg')
+
+    def test_read_write_text(self):
+        p = self.cls(BASE)
+        (p / 'fileA').write_text('äbcdefg', encoding='latin-1')
+        self.assertEqual((p / 'fileA').read_text(
+            encoding='utf-8', errors='ignore'), 'bcdefg')
+        # check that trying to write bytes does not truncate the file
+        self.assertRaises(TypeError, (p / 'fileA').write_text, b'somebytes')
+        self.assertEqual((p / 'fileA').read_text(encoding='latin-1'), 'äbcdefg')
+
     def test_iterdir(self):
         P = self.cls
         p = P(BASE)
@@ -1604,6 +1661,59 @@ class _BasePathTest(object):
         # the parent's permissions follow the default process settings
         self.assertEqual(stat.S_IMODE(p.parent.stat().st_mode), mode)
 
+    def test_mkdir_exist_ok(self):
+        p = self.cls(BASE, 'dirB')
+        st_ctime_first = p.stat().st_ctime
+        self.assertTrue(p.exists())
+        self.assertTrue(p.is_dir())
+        with self.assertRaises(FileExistsError) as cm:
+            p.mkdir()
+        self.assertEqual(cm.exception.errno, errno.EEXIST)
+        p.mkdir(exist_ok=True)
+        self.assertTrue(p.exists())
+        self.assertEqual(p.stat().st_ctime, st_ctime_first)
+
+    def test_mkdir_exist_ok_with_parent(self):
+        p = self.cls(BASE, 'dirC')
+        self.assertTrue(p.exists())
+        with self.assertRaises(FileExistsError) as cm:
+            p.mkdir()
+        self.assertEqual(cm.exception.errno, errno.EEXIST)
+        p = p / 'newdirC'
+        p.mkdir(parents=True)
+        st_ctime_first = p.stat().st_ctime
+        self.assertTrue(p.exists())
+        with self.assertRaises(FileExistsError) as cm:
+            p.mkdir(parents=True)
+        self.assertEqual(cm.exception.errno, errno.EEXIST)
+        p.mkdir(parents=True, exist_ok=True)
+        self.assertTrue(p.exists())
+        self.assertEqual(p.stat().st_ctime, st_ctime_first)
+
+    def test_mkdir_with_child_file(self):
+        p = self.cls(BASE, 'dirB', 'fileB')
+        self.assertTrue(p.exists())
+        # An exception is raised when the last path component is an existing
+        # regular file, regardless of whether exist_ok is true or not.
+        with self.assertRaises(FileExistsError) as cm:
+            p.mkdir(parents=True)
+        self.assertEqual(cm.exception.errno, errno.EEXIST)
+        with self.assertRaises(FileExistsError) as cm:
+            p.mkdir(parents=True, exist_ok=True)
+        self.assertEqual(cm.exception.errno, errno.EEXIST)
+
+    def test_mkdir_no_parents_file(self):
+        p = self.cls(BASE, 'fileA')
+        self.assertTrue(p.exists())
+        # An exception is raised when the last path component is an existing
+        # regular file, regardless of whether exist_ok is true or not.
+        with self.assertRaises(FileExistsError) as cm:
+            p.mkdir()
+        self.assertEqual(cm.exception.errno, errno.EEXIST)
+        with self.assertRaises(FileExistsError) as cm:
+            p.mkdir(exist_ok=True)
+        self.assertEqual(cm.exception.errno, errno.EEXIST)
+
     @with_symlinks
     def test_symlink_to(self):
         P = self.cls(BASE)
@@ -1846,7 +1956,6 @@ class PosixPathTest(_BasePathTest, unittest.TestCase):
     @with_symlinks
     def test_resolve_loop(self):
         # Loop detection for broken symlinks under POSIX
-        P = self.cls
         # Loops with relative symlinks
         os.symlink('linkX/inside', join('linkX'))
         self._check_symlink_loop(BASE, 'linkX')
@@ -1878,6 +1987,48 @@ class PosixPathTest(_BasePathTest, unittest.TestCase):
         self.assertEqual(given, expect)
         self.assertEqual(set(p.rglob("FILEd*")), set())
 
+    def test_expanduser(self):
+        P = self.cls
+        support.import_module('pwd')
+        import pwd
+        pwdent = pwd.getpwuid(os.getuid())
+        username = pwdent.pw_name
+        userhome = pwdent.pw_dir.rstrip('/')
+        # find arbitrary different user (if exists)
+        for pwdent in pwd.getpwall():
+            othername = pwdent.pw_name
+            otherhome = pwdent.pw_dir.rstrip('/')
+            if othername != username and otherhome:
+                break
+
+        p1 = P('~/Documents')
+        p2 = P('~' + username + '/Documents')
+        p3 = P('~' + othername + '/Documents')
+        p4 = P('../~' + username + '/Documents')
+        p5 = P('/~' + username + '/Documents')
+        p6 = P('')
+        p7 = P('~fakeuser/Documents')
+
+        with support.EnvironmentVarGuard() as env:
+            env.pop('HOME', None)
+
+            self.assertEqual(p1.expanduser(), P(userhome) / 'Documents')
+            self.assertEqual(p2.expanduser(), P(userhome) / 'Documents')
+            self.assertEqual(p3.expanduser(), P(otherhome) / 'Documents')
+            self.assertEqual(p4.expanduser(), p4)
+            self.assertEqual(p5.expanduser(), p5)
+            self.assertEqual(p6.expanduser(), p6)
+            self.assertRaises(RuntimeError, p7.expanduser)
+
+            env['HOME'] = '/tmp'
+            self.assertEqual(p1.expanduser(), P('/tmp/Documents'))
+            self.assertEqual(p2.expanduser(), P(userhome) / 'Documents')
+            self.assertEqual(p3.expanduser(), P(otherhome) / 'Documents')
+            self.assertEqual(p4.expanduser(), p4)
+            self.assertEqual(p5.expanduser(), p5)
+            self.assertEqual(p6.expanduser(), p6)
+            self.assertRaises(RuntimeError, p7.expanduser)
+
 
 @only_nt
 class WindowsPathTest(_BasePathTest, unittest.TestCase):
@@ -1893,6 +2044,61 @@ class WindowsPathTest(_BasePathTest, unittest.TestCase):
         p = P(BASE, "dirC")
         self.assertEqual(set(p.rglob("FILEd")), { P(BASE, "dirC/dirD/fileD") })
 
+    def test_expanduser(self):
+        P = self.cls
+        with support.EnvironmentVarGuard() as env:
+            env.pop('HOME', None)
+            env.pop('USERPROFILE', None)
+            env.pop('HOMEPATH', None)
+            env.pop('HOMEDRIVE', None)
+            env['USERNAME'] = 'alice'
+
+            # test that the path returns unchanged
+            p1 = P('~/My Documents')
+            p2 = P('~alice/My Documents')
+            p3 = P('~bob/My Documents')
+            p4 = P('/~/My Documents')
+            p5 = P('d:~/My Documents')
+            p6 = P('')
+            self.assertRaises(RuntimeError, p1.expanduser)
+            self.assertRaises(RuntimeError, p2.expanduser)
+            self.assertRaises(RuntimeError, p3.expanduser)
+            self.assertEqual(p4.expanduser(), p4)
+            self.assertEqual(p5.expanduser(), p5)
+            self.assertEqual(p6.expanduser(), p6)
+
+            def check():
+                env.pop('USERNAME', None)
+                self.assertEqual(p1.expanduser(),
+                                 P('C:/Users/alice/My Documents'))
+                self.assertRaises(KeyError, p2.expanduser)
+                env['USERNAME'] = 'alice'
+                self.assertEqual(p2.expanduser(),
+                                 P('C:/Users/alice/My Documents'))
+                self.assertEqual(p3.expanduser(),
+                                 P('C:/Users/bob/My Documents'))
+                self.assertEqual(p4.expanduser(), p4)
+                self.assertEqual(p5.expanduser(), p5)
+                self.assertEqual(p6.expanduser(), p6)
+
+            # test the first lookup key in the env vars
+            env['HOME'] = 'C:\\Users\\alice'
+            check()
+
+            # test that HOMEPATH is available instead
+            env.pop('HOME', None)
+            env['HOMEPATH'] = 'C:\\Users\\alice'
+            check()
+
+            env['HOMEDRIVE'] = 'C:\\'
+            env['HOMEPATH'] = 'Users\\alice'
+            check()
+
+            env.pop('HOMEDRIVE', None)
+            env.pop('HOMEPATH', None)
+            env['USERPROFILE'] = 'C:\\Users\\alice'
+            check()
+
 
 if __name__ == "__main__":
     unittest.main()
diff --git a/Lib/test/test_pkgutil.py b/Lib/test/test_pkgutil.py
index e0c8635de1..57ebf1fd7f 100644
--- a/Lib/test/test_pkgutil.py
+++ b/Lib/test/test_pkgutil.py
@@ -104,6 +104,9 @@ class PkgutilTests(unittest.TestCase):
 class PkgutilPEP302Tests(unittest.TestCase):
 
     class MyTestLoader(object):
+        def create_module(self, spec):
+            return None
+
         def exec_module(self, mod):
             # Count how many times the module is reloaded
             mod.__dict__['loads'] = mod.__dict__.get('loads', 0) + 1
diff --git a/Lib/test/test_platform.py b/Lib/test/test_platform.py
index b3de43b7ab..ededbdba42 100644
--- a/Lib/test/test_platform.py
+++ b/Lib/test/test_platform.py
@@ -307,7 +307,7 @@ class PlatformTest(unittest.TestCase):
             with mock.patch('platform._UNIXCONFDIR', tempdir):
                 distname, version, distid = platform.linux_distribution()
 
-            self.assertEqual(distname, 'Fedora')
+                self.assertEqual(distname, 'Fedora')
             self.assertEqual(version, '19')
             self.assertEqual(distid, 'Schr\xf6dinger\u2019s Cat')
 
diff --git a/Lib/test/test_poplib.py b/Lib/test/test_poplib.py
index 8a3c9f42fa..14a519d8ec 100644
--- a/Lib/test/test_poplib.py
+++ b/Lib/test/test_poplib.py
@@ -345,23 +345,18 @@ class TestPOP3Class(TestCase):
 
 
 if SUPPORTS_SSL:
+    from test.test_ftplib import SSLConnection
 
-    class DummyPOP3_SSLHandler(DummyPOP3Handler):
+    class DummyPOP3_SSLHandler(SSLConnection, DummyPOP3Handler):
 
         def __init__(self, conn):
             asynchat.async_chat.__init__(self, conn)
-            ssl_socket = ssl.wrap_socket(self.socket, certfile=CERTFILE,
-                                          server_side=True,
-                                          do_handshake_on_connect=False)
-            self.del_channel()
-            self.set_socket(ssl_socket)
-            # Must try handshake before calling push()
-            self.tls_active = True
-            self.tls_starting = True
-            self._do_tls_handshake()
+            self.secure_connection()
             self.set_terminator(b"\r\n")
             self.in_buffer = []
             self.push('+OK dummy pop3 server ready. <timestamp>')
+            self.tls_active = True
+            self.tls_starting = False
 
 
 @requires_ssl
@@ -452,7 +447,7 @@ class TestTimeouts(TestCase):
         del self.thread  # Clear out any dangling Thread objects.
 
     def server(self, evt, serv):
-        serv.listen(5)
+        serv.listen()
         evt.set()
         try:
             conn, addr = serv.accept()
diff --git a/Lib/test/test_posix.py b/Lib/test/test_posix.py
index 72fdd16f8d..f37f2de11c 100644
--- a/Lib/test/test_posix.py
+++ b/Lib/test/test_posix.py
@@ -9,7 +9,6 @@ import errno
 import sys
 import time
 import os
-import fcntl
 import platform
 import pwd
 import shutil
@@ -355,7 +354,7 @@ class PosixTester(unittest.TestCase):
     def test_oscloexec(self):
         fd = os.open(support.TESTFN, os.O_RDONLY|os.O_CLOEXEC)
         self.addCleanup(os.close, fd)
-        self.assertTrue(fcntl.fcntl(fd, fcntl.F_GETFD) & fcntl.FD_CLOEXEC)
+        self.assertFalse(os.get_inheritable(fd))
 
     @unittest.skipUnless(hasattr(posix, 'O_EXLOCK'),
                          'test needs posix.O_EXLOCK')
@@ -605,8 +604,8 @@ class PosixTester(unittest.TestCase):
         self.addCleanup(os.close, w)
         self.assertFalse(os.get_inheritable(r))
         self.assertFalse(os.get_inheritable(w))
-        self.assertTrue(fcntl.fcntl(r, fcntl.F_GETFL) & os.O_NONBLOCK)
-        self.assertTrue(fcntl.fcntl(w, fcntl.F_GETFL) & os.O_NONBLOCK)
+        self.assertFalse(os.get_blocking(r))
+        self.assertFalse(os.get_blocking(w))
         # try reading from an empty pipe: this should fail, not block
         self.assertRaises(OSError, os.read, r, 1)
         # try a write big enough to fill-up the pipe: this should either
diff --git a/Lib/test/test_posixpath.py b/Lib/test/test_posixpath.py
index ec2fbaee32..b2454794e5 100644
--- a/Lib/test/test_posixpath.py
+++ b/Lib/test/test_posixpath.py
@@ -57,18 +57,6 @@ class PosixPathTest(unittest.TestCase):
         self.assertEqual(posixpath.join(b"/foo/", b"bar/", b"baz/"),
                          b"/foo/bar/baz/")
 
-    def test_join_errors(self):
-        # Check posixpath.join raises friendly TypeErrors.
-        errmsg = "Can't mix strings and bytes in path components"
-        with self.assertRaisesRegex(TypeError, errmsg):
-            posixpath.join(b'bytes', 'str')
-        with self.assertRaisesRegex(TypeError, errmsg):
-            posixpath.join('str', b'bytes')
-        # regression, see #15377
-        with self.assertRaises(TypeError) as cm:
-            posixpath.join(None, 'str')
-        self.assertNotEqual(cm.exception.args[0], errmsg)
-
     def test_split(self):
         self.assertEqual(posixpath.split("/foo/bar"), ("/foo", "bar"))
         self.assertEqual(posixpath.split("/"), ("/", ""))
diff --git a/Lib/test/test_pprint.py b/Lib/test/test_pprint.py
index ad6a7a144a..c0568808a0 100644
--- a/Lib/test/test_pprint.py
+++ b/Lib/test/test_pprint.py
@@ -192,10 +192,52 @@ class QueryTestCase(unittest.TestCase):
         o = [o1, o2]
         expected = """\
 [   [0, 1, 2, 3, 4, 5, 6, 7, 8, 9],
+    {'first': 1, 'second': 2, 'third': 3}]"""
+        self.assertEqual(pprint.pformat(o, indent=4, width=42), expected)
+        expected = """\
+[   [0, 1, 2, 3, 4, 5, 6, 7, 8, 9],
     {   'first': 1,
         'second': 2,
         'third': 3}]"""
-        self.assertEqual(pprint.pformat(o, indent=4, width=42), expected)
+        self.assertEqual(pprint.pformat(o, indent=4, width=41), expected)
+
+    def test_width(self):
+        expected = """\
+[[[[[[1, 2, 3],
+     '1 2']]]],
+ {1: [1, 2, 3],
+  2: [12, 34]},
+ 'abc def ghi',
+ ('ab cd ef',),
+ set2({1, 23}),
+ [[[[[1, 2, 3],
+     '1 2']]]]]"""
+        o = eval(expected)
+        self.assertEqual(pprint.pformat(o, width=15), expected)
+        self.assertEqual(pprint.pformat(o, width=16), expected)
+        self.assertEqual(pprint.pformat(o, width=25), expected)
+        self.assertEqual(pprint.pformat(o, width=14), """\
+[[[[[[1,
+      2,
+      3],
+     '1 '
+     '2']]]],
+ {1: [1,
+      2,
+      3],
+  2: [12,
+      34]},
+ 'abc def '
+ 'ghi',
+ ('ab cd '
+  'ef',),
+ set2({1,
+       23}),
+ [[[[[1,
+      2,
+      3],
+     '1 '
+     '2']]]]]""")
 
     def test_sorted_dict(self):
         # Starting in Python 2.5, pprint sorts dict displays by key regardless
@@ -535,13 +577,12 @@ frozenset2({0,
     def test_str_wrap(self):
         # pprint tries to wrap strings intelligently
         fox = 'the quick brown fox jumped over a lazy dog'
-        self.assertEqual(pprint.pformat(fox, width=20), """\
-('the quick '
- 'brown fox '
- 'jumped over a '
- 'lazy dog')""")
+        self.assertEqual(pprint.pformat(fox, width=19), """\
+('the quick brown '
+ 'fox jumped over '
+ 'a lazy dog')""")
         self.assertEqual(pprint.pformat({'a': 1, 'b': fox, 'c': 2},
-                                        width=26), """\
+                                        width=25), """\
 {'a': 1,
  'b': 'the quick brown '
       'fox jumped over '
@@ -553,12 +594,34 @@ frozenset2({0,
         # - non-ASCII is allowed
         # - an apostrophe doesn't disrupt the pprint
         special = "Portons dix bons \"whiskys\"\nà l'avocat goujat\t qui fumait au zoo"
-        self.assertEqual(pprint.pformat(special, width=21), """\
-('Portons dix '
- 'bons "whiskys"\\n'
+        self.assertEqual(pprint.pformat(special, width=68), repr(special))
+        self.assertEqual(pprint.pformat(special, width=31), """\
+('Portons dix bons "whiskys"\\n'
+ "à l'avocat goujat\\t qui "
+ 'fumait au zoo')""")
+        self.assertEqual(pprint.pformat(special, width=20), """\
+('Portons dix bons '
+ '"whiskys"\\n'
  "à l'avocat "
  'goujat\\t qui '
  'fumait au zoo')""")
+        self.assertEqual(pprint.pformat([[[[[special]]]]], width=35), """\
+[[[[['Portons dix bons "whiskys"\\n'
+     "à l'avocat goujat\\t qui "
+     'fumait au zoo']]]]]""")
+        self.assertEqual(pprint.pformat([[[[[special]]]]], width=25), """\
+[[[[['Portons dix bons '
+     '"whiskys"\\n'
+     "à l'avocat "
+     'goujat\\t qui '
+     'fumait au zoo']]]]]""")
+        self.assertEqual(pprint.pformat([[[[[special]]]]], width=23), """\
+[[[[['Portons dix '
+     'bons "whiskys"\\n'
+     "à l'avocat "
+     'goujat\\t qui '
+     'fumait au '
+     'zoo']]]]]""")
         # An unwrappable string is formatted as its repr
         unwrappable = "x" * 100
         self.assertEqual(pprint.pformat(unwrappable, width=80), repr(unwrappable))
@@ -581,7 +644,19 @@ frozenset2({0,
   14, 15],
  [], [0], [0, 1], [0, 1, 2], [0, 1, 2, 3],
  [0, 1, 2, 3, 4]]"""
-        self.assertEqual(pprint.pformat(o, width=48, compact=True), expected)
+        self.assertEqual(pprint.pformat(o, width=47, compact=True), expected)
+
+    def test_compact_width(self):
+        levels = 20
+        number = 10
+        o = [0] * number
+        for i in range(levels - 1):
+            o = [o]
+        for w in range(levels * 2 + 1, levels + 3 * number - 1):
+            lines = pprint.pformat(o, width=w, compact=True).splitlines()
+            maxwidth = max(map(len, lines))
+            self.assertLessEqual(maxwidth, w)
+            self.assertGreater(maxwidth, w - 3)
 
 
 class DottedPrettyPrinter(pprint.PrettyPrinter):
diff --git a/Lib/test/test_pty.py b/Lib/test/test_pty.py
index 8916861f5b..9b783c3768 100644
--- a/Lib/test/test_pty.py
+++ b/Lib/test/test_pty.py
@@ -1,7 +1,6 @@
 from test.support import verbose, run_unittest, import_module, reap_children
 
-#Skip these tests if either fcntl or termios is not available
-fcntl = import_module('fcntl')
+# Skip these tests if termios is not available
 import_module('termios')
 
 import errno
@@ -84,16 +83,18 @@ class PtyTest(unittest.TestCase):
         # in master_open(), we need to read the EOF.
 
         # Ensure the fd is non-blocking in case there's nothing to read.
-        orig_flags = fcntl.fcntl(master_fd, fcntl.F_GETFL)
-        fcntl.fcntl(master_fd, fcntl.F_SETFL, orig_flags | os.O_NONBLOCK)
+        blocking = os.get_blocking(master_fd)
         try:
-            s1 = os.read(master_fd, 1024)
-            self.assertEqual(b'', s1)
-        except OSError as e:
-            if e.errno != errno.EAGAIN:
-                raise
-        # Restore the original flags.
-        fcntl.fcntl(master_fd, fcntl.F_SETFL, orig_flags)
+            os.set_blocking(master_fd, False)
+            try:
+                s1 = os.read(master_fd, 1024)
+                self.assertEqual(b'', s1)
+            except OSError as e:
+                if e.errno != errno.EAGAIN:
+                    raise
+        finally:
+            # Restore the original flags.
+            os.set_blocking(master_fd, blocking)
 
         debug("Writing to slave_fd")
         os.write(slave_fd, TEST_STRING_1)
diff --git a/Lib/test/test_pydoc.py b/Lib/test/test_pydoc.py
index 1427c77fb1..41ad792144 100644
--- a/Lib/test/test_pydoc.py
+++ b/Lib/test/test_pydoc.py
@@ -2,7 +2,6 @@ import os
 import sys
 import builtins
 import contextlib
-import difflib
 import importlib.util
 import inspect
 import pydoc
@@ -360,15 +359,6 @@ def get_pydoc_text(module):
     output = patt.sub('', output)
     return output.strip(), loc
 
-def print_diffs(text1, text2):
-    "Prints unified diffs for two texts"
-    # XXX now obsolete, use unittest built-in support
-    lines1 = text1.splitlines(keepends=True)
-    lines2 = text2.splitlines(keepends=True)
-    diffs = difflib.unified_diff(lines1, lines2, n=0, fromfile='expected',
-                                 tofile='got')
-    print('\n' + ''.join(diffs))
-
 def get_html_title(text):
     # Bit of hack, but good enough for test purposes
     header, _, _ = text.partition("</head>")
@@ -414,9 +404,7 @@ class PydocDocTest(unittest.TestCase):
         expected_html = expected_html_pattern % (
                         (mod_url, mod_file, doc_loc) +
                         expected_html_data_docstrings)
-        if result != expected_html:
-            print_diffs(expected_html, result)
-            self.fail("outputs are not equal, see diff above")
+        self.assertEqual(result, expected_html)
 
     @unittest.skipIf(sys.flags.optimize >= 2,
                      "Docstrings are omitted with -O2 and above")
@@ -429,9 +417,7 @@ class PydocDocTest(unittest.TestCase):
                         (doc_loc,) +
                         expected_text_data_docstrings +
                         (inspect.getabsfile(pydoc_mod),))
-        if result != expected_text:
-            print_diffs(expected_text, result)
-            self.fail("outputs are not equal, see diff above")
+        self.assertEqual(expected_text, result)
 
     def test_text_enum_member_with_value_zero(self):
         # Test issue #20654 to ensure enum member with value 0 can be
@@ -918,9 +904,7 @@ class PydocWithMetaClasses(unittest.TestCase):
         expected_text = expected_dynamicattribute_pattern % (
                 (__name__,) + expected_text_data_docstrings[:2])
         result = output.getvalue().strip()
-        if result != expected_text:
-            print_diffs(expected_text, result)
-            self.fail("outputs are not equal, see diff above")
+        self.assertEqual(expected_text, result)
 
     @unittest.skipIf(sys.flags.optimize >= 2,
                      "Docstrings are omitted with -O2 and above")
@@ -941,9 +925,7 @@ class PydocWithMetaClasses(unittest.TestCase):
         helper(Class)
         expected_text = expected_virtualattribute_pattern1 % __name__
         result = output.getvalue().strip()
-        if result != expected_text:
-            print_diffs(expected_text, result)
-            self.fail("outputs are not equal, see diff above")
+        self.assertEqual(expected_text, result)
 
     @unittest.skipIf(sys.flags.optimize >= 2,
                      "Docstrings are omitted with -O2 and above")
@@ -983,19 +965,13 @@ class PydocWithMetaClasses(unittest.TestCase):
         helper(Class1)
         expected_text1 = expected_virtualattribute_pattern2 % __name__
         result1 = output.getvalue().strip()
-        if result1 != expected_text1:
-            print_diffs(expected_text1, result1)
-            fail1 = True
+        self.assertEqual(expected_text1, result1)
         output = StringIO()
         helper = pydoc.Helper(output=output)
         helper(Class2)
         expected_text2 = expected_virtualattribute_pattern3 % __name__
         result2 = output.getvalue().strip()
-        if result2 != expected_text2:
-            print_diffs(expected_text2, result2)
-            fail2 = True
-        if fail1 or fail2:
-            self.fail("outputs are not equal, see diff above")
+        self.assertEqual(expected_text2, result2)
 
     @unittest.skipIf(sys.flags.optimize >= 2,
                      "Docstrings are omitted with -O2 and above")
@@ -1012,9 +988,7 @@ class PydocWithMetaClasses(unittest.TestCase):
         helper(C)
         expected_text = expected_missingattribute_pattern % __name__
         result = output.getvalue().strip()
-        if result != expected_text:
-            print_diffs(expected_text, result)
-            self.fail("outputs are not equal, see diff above")
+        self.assertEqual(expected_text, result)
 
 
 @reap_threads
diff --git a/Lib/test/test_re.py b/Lib/test/test_re.py
index d2547d4a96..2fb4764abf 100644
--- a/Lib/test/test_re.py
+++ b/Lib/test/test_re.py
@@ -84,7 +84,7 @@ class ReTests(unittest.TestCase):
         self.assertEqual(re.sub("(?i)b+", "x", "bbbb BBBB"), 'x x')
         self.assertEqual(re.sub(r'\d+', self.bump_num, '08.2 -2 23x99y'),
                          '9.3 -3 24x100y')
-        self.assertEqual(re.sub(r'\d+', self.bump_num, '08.2 -2 23x99y', 3),
+        self.assertEqual(re.sub(r'\d+', self.bump_num, '08.2 -2 23x99y', count=3),
                          '9.3 -3 23x99y')
 
         self.assertEqual(re.sub('.', lambda m: r"\n", 'x'), '\\n')
@@ -155,8 +155,8 @@ class ReTests(unittest.TestCase):
         self.assertEqual(re.sub('x', r'\09', 'x'), '\0' + '9')
         self.assertEqual(re.sub('x', r'\0a', 'x'), '\0' + 'a')
 
-        self.assertEqual(re.sub('x', r'\400', 'x'), '\0')
-        self.assertEqual(re.sub('x', r'\777', 'x'), '\377')
+        self.assertRaises(re.error, re.sub, 'x', r'\400', 'x')
+        self.assertRaises(re.error, re.sub, 'x', r'\777', 'x')
 
         self.assertRaises(re.error, re.sub, 'x', r'\1', 'x')
         self.assertRaises(re.error, re.sub, 'x', r'\8', 'x')
@@ -180,7 +180,7 @@ class ReTests(unittest.TestCase):
 
     def test_qualified_re_sub(self):
         self.assertEqual(re.sub('a', 'b', 'aaaaa'), 'bbbbb')
-        self.assertEqual(re.sub('a', 'b', 'aaaaa', 1), 'baaaa')
+        self.assertEqual(re.sub('a', 'b', 'aaaaa', count=1), 'baaaa')
 
     def test_bug_114660(self):
         self.assertEqual(re.sub(r'(\S)\s+(\S)', r'\1 \2', 'hello  there'),
@@ -194,6 +194,7 @@ class ReTests(unittest.TestCase):
     def test_symbolic_groups(self):
         re.compile('(?P<a>x)(?P=a)(?(a)y)')
         re.compile('(?P<a1>x)(?P=a1)(?(a1)y)')
+        re.compile('(?P<a1>x)\1(?(1)y)')
         self.assertRaises(re.error, re.compile, '(?P<a>)(?P<a>)')
         self.assertRaises(re.error, re.compile, '(?Px)')
         self.assertRaises(re.error, re.compile, '(?P=)')
@@ -213,6 +214,10 @@ class ReTests(unittest.TestCase):
         re.compile('(?P<µ>x)(?P=µ)(?(µ)y)')
         re.compile('(?P<𝔘𝔫𝔦𝔠𝔬𝔡𝔢>x)(?P=𝔘𝔫𝔦𝔠𝔬𝔡𝔢)(?(𝔘𝔫𝔦𝔠𝔬𝔡𝔢)y)')
         self.assertRaises(re.error, re.compile, '(?P<©>x)')
+        # Support > 100 groups.
+        pat = '|'.join('x(?P<a%d>%x)y' % (i, i) for i in range(1, 200 + 1))
+        pat = '(?:%s)(?(200)z|t)' % pat
+        self.assertEqual(re.match(pat, 'xc8yz').span(), (0, 5))
 
     def test_symbolic_refs(self):
         self.assertRaises(re.error, re.sub, '(?P<a>x)', '\g<a', 'xx')
@@ -221,48 +226,53 @@ class ReTests(unittest.TestCase):
         self.assertRaises(re.error, re.sub, '(?P<a>x)', '\g<a a>', 'xx')
         self.assertRaises(re.error, re.sub, '(?P<a>x)', '\g<>', 'xx')
         self.assertRaises(re.error, re.sub, '(?P<a>x)', '\g<1a1>', 'xx')
+        self.assertRaises(re.error, re.sub, '(?P<a>x)', r'\g<2>', 'xx')
+        self.assertRaises(re.error, re.sub, '(?P<a>x)', r'\2', 'xx')
         self.assertRaises(IndexError, re.sub, '(?P<a>x)', '\g<ab>', 'xx')
-        self.assertRaises(re.error, re.sub, '(?P<a>x)|(?P<b>y)', '\g<b>', 'xx')
-        self.assertRaises(re.error, re.sub, '(?P<a>x)|(?P<b>y)', '\\2', 'xx')
+        self.assertEqual(re.sub('(?P<a>x)|(?P<b>y)', r'\g<b>', 'xx'), '')
+        self.assertEqual(re.sub('(?P<a>x)|(?P<b>y)', r'\2', 'xx'), '')
         self.assertRaises(re.error, re.sub, '(?P<a>x)', '\g<-1>', 'xx')
         # New valid/invalid identifiers in Python 3
         self.assertEqual(re.sub('(?P<µ>x)', r'\g<µ>', 'xx'), 'xx')
         self.assertEqual(re.sub('(?P<𝔘𝔫𝔦𝔠𝔬𝔡𝔢>x)', r'\g<𝔘𝔫𝔦𝔠𝔬𝔡𝔢>', 'xx'), 'xx')
         self.assertRaises(re.error, re.sub, '(?P<a>x)', r'\g<©>', 'xx')
+        # Support > 100 groups.
+        pat = '|'.join('x(?P<a%d>%x)y' % (i, i) for i in range(1, 200 + 1))
+        self.assertEqual(re.sub(pat, '\g<200>', 'xc8yzxc8y'), 'c8zc8')
 
     def test_re_subn(self):
         self.assertEqual(re.subn("(?i)b+", "x", "bbbb BBBB"), ('x x', 2))
         self.assertEqual(re.subn("b+", "x", "bbbb BBBB"), ('x BBBB', 1))
         self.assertEqual(re.subn("b+", "x", "xyz"), ('xyz', 0))
         self.assertEqual(re.subn("b*", "x", "xyz"), ('xxxyxzx', 4))
-        self.assertEqual(re.subn("b*", "x", "xyz", 2), ('xxxyz', 2))
+        self.assertEqual(re.subn("b*", "x", "xyz", count=2), ('xxxyz', 2))
 
     def test_re_split(self):
         for string in ":a:b::c", S(":a:b::c"):
             self.assertTypedEqual(re.split(":", string),
                                   ['', 'a', 'b', '', 'c'])
-            self.assertTypedEqual(re.split(":*", string),
+            self.assertTypedEqual(re.split(":+", string),
                                   ['', 'a', 'b', 'c'])
-            self.assertTypedEqual(re.split("(:*)", string),
+            self.assertTypedEqual(re.split("(:+)", string),
                                   ['', ':', 'a', ':', 'b', '::', 'c'])
         for string in (b":a:b::c", B(b":a:b::c"), bytearray(b":a:b::c"),
                        memoryview(b":a:b::c")):
             self.assertTypedEqual(re.split(b":", string),
                                   [b'', b'a', b'b', b'', b'c'])
-            self.assertTypedEqual(re.split(b":*", string),
+            self.assertTypedEqual(re.split(b":+", string),
                                   [b'', b'a', b'b', b'c'])
-            self.assertTypedEqual(re.split(b"(:*)", string),
+            self.assertTypedEqual(re.split(b"(:+)", string),
                                   [b'', b':', b'a', b':', b'b', b'::', b'c'])
         for a, b, c in ("\xe0\xdf\xe7", "\u0430\u0431\u0432",
                         "\U0001d49c\U0001d49e\U0001d4b5"):
             string = ":%s:%s::%s" % (a, b, c)
             self.assertEqual(re.split(":", string), ['', a, b, '', c])
-            self.assertEqual(re.split(":*", string), ['', a, b, c])
-            self.assertEqual(re.split("(:*)", string),
+            self.assertEqual(re.split(":+", string), ['', a, b, c])
+            self.assertEqual(re.split("(:+)", string),
                              ['', ':', a, ':', b, '::', c])
 
-        self.assertEqual(re.split("(?::*)", ":a:b::c"), ['', 'a', 'b', 'c'])
-        self.assertEqual(re.split("(:)*", ":a:b::c"),
+        self.assertEqual(re.split("(?::+)", ":a:b::c"), ['', 'a', 'b', 'c'])
+        self.assertEqual(re.split("(:)+", ":a:b::c"),
                          ['', ':', 'a', ':', 'b', ':', 'c'])
         self.assertEqual(re.split("([b:]+)", ":a:b::c"),
                          ['', ':', 'a', ':b::', 'c'])
@@ -272,13 +282,34 @@ class ReTests(unittest.TestCase):
         self.assertEqual(re.split("(?:b)|(?::+)", ":a:b::c"),
                          ['', 'a', '', '', 'c'])
 
+        for sep, expected in [
+            (':*', ['', 'a', 'b', 'c']),
+            ('(?::*)', ['', 'a', 'b', 'c']),
+            ('(:*)', ['', ':', 'a', ':', 'b', '::', 'c']),
+            ('(:)*', ['', ':', 'a', ':', 'b', ':', 'c']),
+        ]:
+            with self.subTest(sep=sep), self.assertWarns(FutureWarning):
+                self.assertTypedEqual(re.split(sep, ':a:b::c'), expected)
+
+        for sep, expected in [
+            ('', [':a:b::c']),
+            (r'\b', [':a:b::c']),
+            (r'(?=:)', [':a:b::c']),
+            (r'(?<=:)', [':a:b::c']),
+        ]:
+            with self.subTest(sep=sep), self.assertRaises(ValueError):
+                self.assertTypedEqual(re.split(sep, ':a:b::c'), expected)
+
     def test_qualified_re_split(self):
-        self.assertEqual(re.split(":", ":a:b::c", 2), ['', 'a', 'b::c'])
-        self.assertEqual(re.split(':', 'a:b:c:d', 2), ['a', 'b', 'c:d'])
-        self.assertEqual(re.split("(:)", ":a:b::c", 2),
+        self.assertEqual(re.split(":", ":a:b::c", maxsplit=2), ['', 'a', 'b::c'])
+        self.assertEqual(re.split(':', 'a:b:c:d', maxsplit=2), ['a', 'b', 'c:d'])
+        self.assertEqual(re.split("(:)", ":a:b::c", maxsplit=2),
                          ['', ':', 'a', ':', 'b::c'])
-        self.assertEqual(re.split("(:*)", ":a:b::c", 2),
+        self.assertEqual(re.split("(:+)", ":a:b::c", maxsplit=2),
                          ['', ':', 'a', ':', 'b::c'])
+        with self.assertWarns(FutureWarning):
+            self.assertEqual(re.split("(:*)", ":a:b::c", maxsplit=2),
+                             ['', ':', 'a', ':', 'b::c'])
 
     def test_re_findall(self):
         self.assertEqual(re.findall(":+", "abc"), [])
@@ -405,6 +436,10 @@ class ReTests(unittest.TestCase):
         self.assertIsNone(p.match('abd'))
         self.assertIsNone(p.match('ac'))
 
+        # Support > 100 groups.
+        pat = '|'.join('x(?P<a%d>%x)y' % (i, i) for i in range(1, 200 + 1))
+        pat = '(?:%s)(?(200)z)' % pat
+        self.assertEqual(re.match(pat, 'xc8yz').span(), (0, 5))
 
     def test_re_groupref(self):
         self.assertEqual(re.match(r'^(\|)?([^()]+)\1$', '|a|').groups(),
@@ -428,6 +463,10 @@ class ReTests(unittest.TestCase):
                                   "first second")
                                   .expand(r"\2 \1 \g<second> \g<first>"),
                          "second first second first")
+        self.assertEqual(re.match("(?P<first>first)|(?P<second>second)",
+                                  "first")
+                                  .expand(r"\2 \g<second>"),
+                         " ")
 
     def test_repeat_minmax(self):
         self.assertIsNone(re.match("^(\w){1}$", "abc"))
@@ -484,10 +523,6 @@ class ReTests(unittest.TestCase):
                                    "abcd abc bcd bx", re.ASCII).group(1), "bx")
         self.assertEqual(re.search(r"\B(b.)\B",
                                    "abc bcd bc abxd", re.ASCII).group(1), "bx")
-        self.assertEqual(re.search(r"\b(b.)\b",
-                                   "abcd abc bcd bx", re.LOCALE).group(1), "bx")
-        self.assertEqual(re.search(r"\B(b.)\B",
-                                   "abc bcd bc abxd", re.LOCALE).group(1), "bx")
         self.assertEqual(re.search(r"^abc$", "\nabc\n", re.M).group(0), "abc")
         self.assertEqual(re.search(r"^\Aabc\Z$", "abc", re.M).group(0), "abc")
         self.assertIsNone(re.search(r"^\Aabc\Z$", "\nabc\n", re.M))
@@ -508,11 +543,23 @@ class ReTests(unittest.TestCase):
                                    b"1aa! a").group(0), b"1aa! a")
         self.assertEqual(re.search(r"\d\D\w\W\s\S",
                                    "1aa! a", re.ASCII).group(0), "1aa! a")
-        self.assertEqual(re.search(r"\d\D\w\W\s\S",
-                                   "1aa! a", re.LOCALE).group(0), "1aa! a")
         self.assertEqual(re.search(br"\d\D\w\W\s\S",
                                    b"1aa! a", re.LOCALE).group(0), b"1aa! a")
 
+    def test_other_escapes(self):
+        self.assertRaises(re.error, re.compile, "\\")
+        self.assertEqual(re.match(r"\(", '(').group(), '(')
+        self.assertIsNone(re.match(r"\(", ')'))
+        self.assertEqual(re.match(r"\\", '\\').group(), '\\')
+        self.assertEqual(re.match(r"\y", 'y').group(), 'y')
+        self.assertIsNone(re.match(r"\y", 'z'))
+        self.assertEqual(re.match(r"[\]]", ']').group(), ']')
+        self.assertIsNone(re.match(r"[\]]", '['))
+        self.assertEqual(re.match(r"[a\-c]", '-').group(), '-')
+        self.assertIsNone(re.match(r"[a\-c]", 'b'))
+        self.assertEqual(re.match(r"[\^a]+", 'a^').group(), 'a^')
+        self.assertIsNone(re.match(r"[\^a]+", 'b'))
+
     def test_string_boundaries(self):
         # See http://bugs.python.org/issue10713
         self.assertEqual(re.search(r"\b(abc)\b", "abc").group(1),
@@ -661,9 +708,12 @@ class ReTests(unittest.TestCase):
         self.assertEqual(_sre.getlower(ord('A'), 0), ord('a'))
         self.assertEqual(_sre.getlower(ord('A'), re.LOCALE), ord('a'))
         self.assertEqual(_sre.getlower(ord('A'), re.UNICODE), ord('a'))
+        self.assertEqual(_sre.getlower(ord('A'), re.ASCII), ord('a'))
 
         self.assertEqual(re.match("abc", "ABC", re.I).group(0), "ABC")
         self.assertEqual(re.match(b"abc", b"ABC", re.I).group(0), b"ABC")
+        self.assertEqual(re.match("abc", "ABC", re.I|re.A).group(0), "ABC")
+        self.assertEqual(re.match(b"abc", b"ABC", re.I|re.L).group(0), b"ABC")
 
     def test_not_literal(self):
         self.assertEqual(re.search("\s([^a])", " b").group(1), "b")
@@ -748,8 +798,10 @@ class ReTests(unittest.TestCase):
         self.assertEqual(re.X, re.VERBOSE)
 
     def test_flags(self):
-        for flag in [re.I, re.M, re.X, re.S, re.L]:
+        for flag in [re.I, re.M, re.X, re.S, re.A, re.U]:
             self.assertTrue(re.compile('^pattern$', flag))
+        for flag in [re.I, re.M, re.X, re.S, re.A, re.L]:
+            self.assertTrue(re.compile(b'^pattern$', flag))
 
     def test_sre_character_literals(self):
         for i in [0, 8, 16, 32, 64, 127, 128, 255, 256, 0xFFFF, 0x10000, 0x10FFFF]:
@@ -771,7 +823,7 @@ class ReTests(unittest.TestCase):
         self.assertTrue(re.match(r"\08", "\0008"))
         self.assertTrue(re.match(r"\01", "\001"))
         self.assertTrue(re.match(r"\018", "\0018"))
-        self.assertTrue(re.match(r"\567", chr(0o167)))
+        self.assertRaises(re.error, re.match, r"\567", "")
         self.assertRaises(re.error, re.match, r"\911", "")
         self.assertRaises(re.error, re.match, r"\x1", "")
         self.assertRaises(re.error, re.match, r"\x1z", "")
@@ -799,12 +851,13 @@ class ReTests(unittest.TestCase):
             self.assertTrue(re.match(r"[\U%08x]" % i, chr(i)))
             self.assertTrue(re.match(r"[\U%08x0]" % i, chr(i)+"0"))
             self.assertTrue(re.match(r"[\U%08xz]" % i, chr(i)+"z"))
-        self.assertTrue(re.match(r"[\U0001d49c-\U0001d4b5]", "\U0001d49e"))
+        self.assertRaises(re.error, re.match, r"[\567]", "")
         self.assertRaises(re.error, re.match, r"[\911]", "")
         self.assertRaises(re.error, re.match, r"[\x1z]", "")
         self.assertRaises(re.error, re.match, r"[\u123z]", "")
         self.assertRaises(re.error, re.match, r"[\U0001234z]", "")
         self.assertRaises(re.error, re.match, r"[\U00110000]", "")
+        self.assertTrue(re.match(r"[\U0001d49c-\U0001d4b5]", "\U0001d49e"))
 
     def test_sre_byte_literals(self):
         for i in [0, 8, 16, 32, 64, 127, 128, 255]:
@@ -820,7 +873,7 @@ class ReTests(unittest.TestCase):
         self.assertTrue(re.match(br"\08", b"\0008"))
         self.assertTrue(re.match(br"\01", b"\001"))
         self.assertTrue(re.match(br"\018", b"\0018"))
-        self.assertTrue(re.match(br"\567", bytes([0o167])))
+        self.assertRaises(re.error, re.match, br"\567", b"")
         self.assertRaises(re.error, re.match, br"\911", b"")
         self.assertRaises(re.error, re.match, br"\x1", b"")
         self.assertRaises(re.error, re.match, br"\x1z", b"")
@@ -837,6 +890,7 @@ class ReTests(unittest.TestCase):
             self.assertTrue(re.match((r"[\x%02xz]" % i).encode(), bytes([i])))
         self.assertTrue(re.match(br"[\u]", b'u'))
         self.assertTrue(re.match(br"[\U]", b'U'))
+        self.assertRaises(re.error, re.match, br"[\567]", b"")
         self.assertRaises(re.error, re.match, br"[\911]", b"")
         self.assertRaises(re.error, re.match, br"[\x1z]", b"")
 
@@ -1031,8 +1085,8 @@ class ReTests(unittest.TestCase):
 
     def test_inline_flags(self):
         # Bug #1700
-        upper_char = chr(0x1ea0) # Latin Capital Letter A with Dot Bellow
-        lower_char = chr(0x1ea1) # Latin Small Letter A with Dot Bellow
+        upper_char = '\u1ea0' # Latin Capital Letter A with Dot Below
+        lower_char = '\u1ea1' # Latin Small Letter A with Dot Below
 
         p = re.compile(upper_char, re.I | re.U)
         q = p.match(lower_char)
@@ -1112,6 +1166,52 @@ class ReTests(unittest.TestCase):
         self.assertRaises(ValueError, re.compile, '(?a)\w', re.UNICODE)
         self.assertRaises(ValueError, re.compile, '(?au)\w')
 
+    def test_locale_flag(self):
+        import locale
+        _, enc = locale.getlocale(locale.LC_CTYPE)
+        # Search non-ASCII letter
+        for i in range(128, 256):
+            try:
+                c = bytes([i]).decode(enc)
+                sletter = c.lower()
+                if sletter == c: continue
+                bletter = sletter.encode(enc)
+                if len(bletter) != 1: continue
+                if bletter.decode(enc) != sletter: continue
+                bpat = re.escape(bytes([i]))
+                break
+            except (UnicodeError, TypeError):
+                pass
+        else:
+            bletter = None
+            bpat = b'A'
+        # Bytes patterns
+        pat = re.compile(bpat, re.LOCALE | re.IGNORECASE)
+        if bletter:
+            self.assertTrue(pat.match(bletter))
+        pat = re.compile(b'(?L)' + bpat, re.IGNORECASE)
+        if bletter:
+            self.assertTrue(pat.match(bletter))
+        pat = re.compile(bpat, re.IGNORECASE)
+        if bletter:
+            self.assertIsNone(pat.match(bletter))
+        pat = re.compile(b'\w', re.LOCALE)
+        if bletter:
+            self.assertTrue(pat.match(bletter))
+        pat = re.compile(b'(?L)\w')
+        if bletter:
+            self.assertTrue(pat.match(bletter))
+        pat = re.compile(b'\w')
+        if bletter:
+            self.assertIsNone(pat.match(bletter))
+        # Incompatibilities
+        self.assertWarns(DeprecationWarning, re.compile, '', re.LOCALE)
+        self.assertWarns(DeprecationWarning, re.compile, '(?L)')
+        self.assertWarns(DeprecationWarning, re.compile, b'', re.LOCALE | re.ASCII)
+        self.assertWarns(DeprecationWarning, re.compile, b'(?L)', re.ASCII)
+        self.assertWarns(DeprecationWarning, re.compile, b'(?a)', re.LOCALE)
+        self.assertWarns(DeprecationWarning, re.compile, b'(?aL)')
+
     def test_bug_6509(self):
         # Replacement strings of both types must parse properly.
         # all strings
@@ -1139,8 +1239,10 @@ class ReTests(unittest.TestCase):
         # a RuntimeError is raised instead of OverflowError.
         long_overflow = 2**128
         self.assertRaises(TypeError, re.finditer, "a", {})
-        self.assertRaises(OverflowError, _sre.compile, "abc", 0, [long_overflow])
-        self.assertRaises(TypeError, _sre.compile, {}, 0, [])
+        with self.assertRaises(OverflowError):
+            _sre.compile("abc", 0, [long_overflow], 0, [], [])
+        with self.assertRaises(TypeError):
+            _sre.compile({}, 0, [], 0, [], [])
 
     def test_search_dot_unicode(self):
         self.assertTrue(re.search("123.*-", '123abc-'))
@@ -1278,22 +1380,22 @@ class ReTests(unittest.TestCase):
         with captured_stdout() as out:
             re.compile(pat, re.DEBUG)
         dump = '''\
-subpattern 1
-  literal 46
-subpattern None
-  branch
-    in
-      literal 99
-      literal 104
-  or
-    literal 112
-    literal 121
-subpattern None
-  groupref_exists 1
-    at at_end
-  else
-    literal 58
-    literal 32
+SUBPATTERN 1
+  LITERAL 46
+SUBPATTERN None
+  BRANCH
+    IN
+      LITERAL 99
+      LITERAL 104
+  OR
+    LITERAL 112
+    LITERAL 121
+SUBPATTERN None
+  GROUPREF_EXISTS 1
+    AT AT_END
+  ELSE
+    LITERAL 58
+    LITERAL 32
 '''
         self.assertEqual(out.getvalue(), dump)
         # Debug output is output again even a second time (bypassing
@@ -1361,6 +1463,42 @@ subpattern None
         self.assertIsNone(re.match(b'(?Li)\xc5', b'\xe5'))
         self.assertIsNone(re.match(b'(?Li)\xe5', b'\xc5'))
 
+    def test_error(self):
+        with self.assertRaises(re.error) as cm:
+            re.compile('(\u20ac))')
+        err = cm.exception
+        self.assertIsInstance(err.pattern, str)
+        self.assertEqual(err.pattern, '(\u20ac))')
+        self.assertEqual(err.pos, 3)
+        self.assertEqual(err.lineno, 1)
+        self.assertEqual(err.colno, 4)
+        self.assertIn(err.msg, str(err))
+        self.assertIn(' at position 3', str(err))
+        self.assertNotIn(' at position 3', err.msg)
+        # Bytes pattern
+        with self.assertRaises(re.error) as cm:
+            re.compile(b'(\xa4))')
+        err = cm.exception
+        self.assertIsInstance(err.pattern, bytes)
+        self.assertEqual(err.pattern, b'(\xa4))')
+        self.assertEqual(err.pos, 3)
+        # Multiline pattern
+        with self.assertRaises(re.error) as cm:
+            re.compile("""
+                (
+                    abc
+                )
+                )
+                (
+                """, re.VERBOSE)
+        err = cm.exception
+        self.assertEqual(err.pos, 77)
+        self.assertEqual(err.lineno, 5)
+        self.assertEqual(err.colno, 17)
+        self.assertIn(err.msg, str(err))
+        self.assertIn(' at position 77', str(err))
+        self.assertIn('(line 5, column 17)', str(err))
+
 
 class PatternReprTests(unittest.TestCase):
     def check(self, pattern, expected):
@@ -1405,6 +1543,10 @@ class PatternReprTests(unittest.TestCase):
         self.check_flags(b'bytes pattern', re.A,
                          "re.compile(b'bytes pattern', re.ASCII)")
 
+    def test_locale(self):
+        self.check_flags(b'bytes pattern', re.L,
+                         "re.compile(b'bytes pattern', re.LOCALE)")
+
     def test_quotes(self):
         self.check('random "double quoted" pattern',
             '''re.compile('random "double quoted" pattern')''')
@@ -1518,8 +1660,16 @@ class ExternalTests(unittest.TestCase):
                     pass
                 else:
                     with self.subTest('bytes pattern match'):
-                        bpat = re.compile(bpat)
-                        self.assertTrue(bpat.search(bs))
+                        obj = re.compile(bpat)
+                        self.assertTrue(obj.search(bs))
+
+                    # Try the match with LOCALE enabled, and check that it
+                    # still succeeds.
+                    with self.subTest('locale-sensitive match'):
+                        obj = re.compile(bpat, re.LOCALE)
+                        result = obj.search(bs)
+                        if result is None:
+                            print('=== Fails on locale-sensitive match', t)
 
                 # Try the match with the search area limited to the extent
                 # of the match and see if it still succeeds.  \B will
@@ -1537,13 +1687,6 @@ class ExternalTests(unittest.TestCase):
                     obj = re.compile(pattern, re.IGNORECASE)
                     self.assertTrue(obj.search(s))
 
-                # Try the match with LOCALE enabled, and check that it
-                # still succeeds.
-                if '(?u)' not in pattern:
-                    with self.subTest('locale-sensitive match'):
-                        obj = re.compile(pattern, re.LOCALE)
-                        self.assertTrue(obj.search(s))
-
                 # Try the match with UNICODE locale enabled, and check
                 # that it still succeeds.
                 with self.subTest('unicode-sensitive match'):
diff --git a/Lib/test/test_readline.py b/Lib/test/test_readline.py
index 0b2b0a5c2f..23d6194e8e 100644
--- a/Lib/test/test_readline.py
+++ b/Lib/test/test_readline.py
@@ -2,8 +2,9 @@
 Very minimal unittests for parts of the readline module.
 """
 import os
+import tempfile
 import unittest
-from test.support import run_unittest, import_module
+from test.support import run_unittest, import_module, unlink
 from test.script_helper import assert_python_ok
 
 # Skip tests if there is no readline module
@@ -42,6 +43,45 @@ class TestHistoryManipulation (unittest.TestCase):
 
         self.assertEqual(readline.get_current_history_length(), 1)
 
+    @unittest.skipUnless(hasattr(readline, "append_history_file"),
+                         "append_history not available")
+    def test_write_read_append(self):
+        hfile = tempfile.NamedTemporaryFile(delete=False)
+        hfile.close()
+        hfilename = hfile.name
+        self.addCleanup(unlink, hfilename)
+
+        # test write-clear-read == nop
+        readline.clear_history()
+        readline.add_history("first line")
+        readline.add_history("second line")
+        readline.write_history_file(hfilename)
+
+        readline.clear_history()
+        self.assertEqual(readline.get_current_history_length(), 0)
+
+        readline.read_history_file(hfilename)
+        self.assertEqual(readline.get_current_history_length(), 2)
+        self.assertEqual(readline.get_history_item(1), "first line")
+        self.assertEqual(readline.get_history_item(2), "second line")
+
+        # test append
+        readline.append_history_file(1, hfilename)
+        readline.clear_history()
+        readline.read_history_file(hfilename)
+        self.assertEqual(readline.get_current_history_length(), 3)
+        self.assertEqual(readline.get_history_item(1), "first line")
+        self.assertEqual(readline.get_history_item(2), "second line")
+        self.assertEqual(readline.get_history_item(3), "second line")
+
+        # test 'no such file' behaviour
+        os.unlink(hfilename)
+        with self.assertRaises(FileNotFoundError):
+            readline.append_history_file(1, hfilename)
+
+        # write_history_file can create the target
+        readline.write_history_file(hfilename)
+
 
 class TestReadline(unittest.TestCase):
 
diff --git a/Lib/test/test_reprlib.py b/Lib/test/test_reprlib.py
index ae67f06bc4..a51c4d7523 100644
--- a/Lib/test/test_reprlib.py
+++ b/Lib/test/test_reprlib.py
@@ -10,7 +10,7 @@ import importlib
 import importlib.util
 import unittest
 
-from test.support import run_unittest, create_empty_file, verbose
+from test.support import create_empty_file, verbose
 from reprlib import repr as r # Don't shadow builtin repr
 from reprlib import Repr
 from reprlib import recursive_repr
@@ -70,18 +70,18 @@ class ReprTests(unittest.TestCase):
         eq(r([1, 2, 3, 4, 5, 6, 7]), "[1, 2, 3, 4, 5, 6, ...]")
 
         # Sets give up after 6 as well
-        eq(r(set([])), "set([])")
-        eq(r(set([1])), "set([1])")
-        eq(r(set([1, 2, 3])), "set([1, 2, 3])")
-        eq(r(set([1, 2, 3, 4, 5, 6])), "set([1, 2, 3, 4, 5, 6])")
-        eq(r(set([1, 2, 3, 4, 5, 6, 7])), "set([1, 2, 3, 4, 5, 6, ...])")
+        eq(r(set([])), "set()")
+        eq(r(set([1])), "{1}")
+        eq(r(set([1, 2, 3])), "{1, 2, 3}")
+        eq(r(set([1, 2, 3, 4, 5, 6])), "{1, 2, 3, 4, 5, 6}")
+        eq(r(set([1, 2, 3, 4, 5, 6, 7])), "{1, 2, 3, 4, 5, 6, ...}")
 
         # Frozensets give up after 6 as well
-        eq(r(frozenset([])), "frozenset([])")
-        eq(r(frozenset([1])), "frozenset([1])")
-        eq(r(frozenset([1, 2, 3])), "frozenset([1, 2, 3])")
-        eq(r(frozenset([1, 2, 3, 4, 5, 6])), "frozenset([1, 2, 3, 4, 5, 6])")
-        eq(r(frozenset([1, 2, 3, 4, 5, 6, 7])), "frozenset([1, 2, 3, 4, 5, 6, ...])")
+        eq(r(frozenset([])), "frozenset()")
+        eq(r(frozenset([1])), "frozenset({1})")
+        eq(r(frozenset([1, 2, 3])), "frozenset({1, 2, 3})")
+        eq(r(frozenset([1, 2, 3, 4, 5, 6])), "frozenset({1, 2, 3, 4, 5, 6})")
+        eq(r(frozenset([1, 2, 3, 4, 5, 6, 7])), "frozenset({1, 2, 3, 4, 5, 6, ...})")
 
         # collections.deque after 6
         eq(r(deque([1, 2, 3, 4, 5, 6, 7])), "deque([1, 2, 3, 4, 5, 6, ...])")
@@ -94,7 +94,7 @@ class ReprTests(unittest.TestCase):
         eq(r(d), "{'alice': 1, 'arthur': 1, 'bob': 2, 'charles': 3, ...}")
 
         # array.array after 5.
-        eq(r(array('i')), "array('i', [])")
+        eq(r(array('i')), "array('i')")
         eq(r(array('i', [1])), "array('i', [1])")
         eq(r(array('i', [1, 2])), "array('i', [1, 2])")
         eq(r(array('i', [1, 2, 3])), "array('i', [1, 2, 3])")
@@ -103,6 +103,20 @@ class ReprTests(unittest.TestCase):
         eq(r(array('i', [1, 2, 3, 4, 5, 6])),
                    "array('i', [1, 2, 3, 4, 5, ...])")
 
+    def test_set_literal(self):
+        eq = self.assertEqual
+        eq(r({1}), "{1}")
+        eq(r({1, 2, 3}), "{1, 2, 3}")
+        eq(r({1, 2, 3, 4, 5, 6}), "{1, 2, 3, 4, 5, 6}")
+        eq(r({1, 2, 3, 4, 5, 6, 7}), "{1, 2, 3, 4, 5, 6, ...}")
+
+    def test_frozenset(self):
+        eq = self.assertEqual
+        eq(r(frozenset({1})), "frozenset({1})")
+        eq(r(frozenset({1, 2, 3})), "frozenset({1, 2, 3})")
+        eq(r(frozenset({1, 2, 3, 4, 5, 6})), "frozenset({1, 2, 3, 4, 5, 6})")
+        eq(r(frozenset({1, 2, 3, 4, 5, 6, 7})), "frozenset({1, 2, 3, 4, 5, 6, ...})")
+
     def test_numbers(self):
         eq = self.assertEqual
         eq(r(123), repr(123))
@@ -123,7 +137,7 @@ class ReprTests(unittest.TestCase):
         eq(r(i2), expected)
 
         i3 = ClassWithFailingRepr()
-        eq(r(i3), ("<ClassWithFailingRepr instance at %x>"%id(i3)))
+        eq(r(i3), ("<ClassWithFailingRepr instance at %#x>"%id(i3)))
 
         s = r(ClassWithFailingRepr)
         self.assertTrue(s.startswith("<class "))
@@ -373,11 +387,5 @@ class TestRecursiveRepr(unittest.TestCase):
         m.append(m)
         self.assertEqual(repr(m), '<a, b, c, d, e, +++, x, +++>')
 
-def test_main():
-    run_unittest(ReprTests)
-    run_unittest(LongReprTest)
-    run_unittest(TestRecursiveRepr)
-
-
 if __name__ == "__main__":
-    test_main()
+    unittest.main()
diff --git a/Lib/test/test_script_helper.py b/Lib/test/test_script_helper.py
index 7540e2e99b..74333c9db8 100755
--- a/Lib/test/test_script_helper.py
+++ b/Lib/test/test_script_helper.py
@@ -36,7 +36,7 @@ class TestScriptHelper(unittest.TestCase):
     @mock.patch('subprocess.Popen')
     def test_assert_python_isolated_when_env_not_required(self, mock_popen):
         with mock.patch.object(script_helper,
-                               '_interpreter_requires_environment',
+                               'interpreter_requires_environment',
                                return_value=False) as mock_ire_func:
             mock_popen.side_effect = RuntimeError('bail out of unittest')
             try:
@@ -55,7 +55,7 @@ class TestScriptHelper(unittest.TestCase):
     def test_assert_python_not_isolated_when_env_is_required(self, mock_popen):
         """Ensure that -I is not passed when the environment is required."""
         with mock.patch.object(script_helper,
-                               '_interpreter_requires_environment',
+                               'interpreter_requires_environment',
                                return_value=True) as mock_ire_func:
             mock_popen.side_effect = RuntimeError('bail out of unittest')
             try:
@@ -68,7 +68,7 @@ class TestScriptHelper(unittest.TestCase):
 
 
 class TestScriptHelperEnvironment(unittest.TestCase):
-    """Code coverage for _interpreter_requires_environment()."""
+    """Code coverage for interpreter_requires_environment()."""
 
     def setUp(self):
         self.assertTrue(
@@ -83,22 +83,22 @@ class TestScriptHelperEnvironment(unittest.TestCase):
     @mock.patch('subprocess.check_call')
     def test_interpreter_requires_environment_true(self, mock_check_call):
         mock_check_call.side_effect = subprocess.CalledProcessError('', '')
-        self.assertTrue(script_helper._interpreter_requires_environment())
-        self.assertTrue(script_helper._interpreter_requires_environment())
+        self.assertTrue(script_helper.interpreter_requires_environment())
+        self.assertTrue(script_helper.interpreter_requires_environment())
         self.assertEqual(1, mock_check_call.call_count)
 
     @mock.patch('subprocess.check_call')
     def test_interpreter_requires_environment_false(self, mock_check_call):
         # The mocked subprocess.check_call fakes a no-error process.
-        script_helper._interpreter_requires_environment()
-        self.assertFalse(script_helper._interpreter_requires_environment())
+        script_helper.interpreter_requires_environment()
+        self.assertFalse(script_helper.interpreter_requires_environment())
         self.assertEqual(1, mock_check_call.call_count)
 
     @mock.patch('subprocess.check_call')
     def test_interpreter_requires_environment_details(self, mock_check_call):
-        script_helper._interpreter_requires_environment()
-        self.assertFalse(script_helper._interpreter_requires_environment())
-        self.assertFalse(script_helper._interpreter_requires_environment())
+        script_helper.interpreter_requires_environment()
+        self.assertFalse(script_helper.interpreter_requires_environment())
+        self.assertFalse(script_helper.interpreter_requires_environment())
         self.assertEqual(1, mock_check_call.call_count)
         check_call_command = mock_check_call.call_args[0][0]
         self.assertEqual(sys.executable, check_call_command[0])
diff --git a/Lib/test/test_selectors.py b/Lib/test/test_selectors.py
index 952fda6c69..9521481901 100644
--- a/Lib/test/test_selectors.py
+++ b/Lib/test/test_selectors.py
@@ -9,10 +9,7 @@ from test import support
 from time import sleep
 import unittest
 import unittest.mock
-try:
-    from time import monotonic as time
-except ImportError:
-    from time import time as time
+from time import monotonic as time
 try:
     import resource
 except ImportError:
@@ -25,7 +22,7 @@ else:
     def socketpair(family=socket.AF_INET, type=socket.SOCK_STREAM, proto=0):
         with socket.socket(family, type, proto) as l:
             l.bind((support.HOST, 0))
-            l.listen(3)
+            l.listen()
             c = socket.socket(family, type, proto)
             try:
                 c.connect(l.getsockname())
@@ -188,8 +185,8 @@ class BaseSelectorTestCase(unittest.TestCase):
         s.register(wr, selectors.EVENT_WRITE)
 
         s.close()
-        self.assertRaises(KeyError, s.get_key, rd)
-        self.assertRaises(KeyError, s.get_key, wr)
+        self.assertRaises(RuntimeError, s.get_key, rd)
+        self.assertRaises(RuntimeError, s.get_key, wr)
         self.assertRaises(KeyError, mapping.__getitem__, rd)
         self.assertRaises(KeyError, mapping.__getitem__, wr)
 
@@ -258,8 +255,8 @@ class BaseSelectorTestCase(unittest.TestCase):
             sel.register(rd, selectors.EVENT_READ)
             sel.register(wr, selectors.EVENT_WRITE)
 
-        self.assertRaises(KeyError, s.get_key, rd)
-        self.assertRaises(KeyError, s.get_key, wr)
+        self.assertRaises(RuntimeError, s.get_key, rd)
+        self.assertRaises(RuntimeError, s.get_key, wr)
 
     def test_fileno(self):
         s = self.SELECTOR()
@@ -455,10 +452,18 @@ class KqueueSelectorTestCase(BaseSelectorTestCase, ScalableSelectorMixIn):
     SELECTOR = getattr(selectors, 'KqueueSelector', None)
 
 
+@unittest.skipUnless(hasattr(selectors, 'DevpollSelector'),
+                     "Test needs selectors.DevpollSelector")
+class DevpollSelectorTestCase(BaseSelectorTestCase, ScalableSelectorMixIn):
+
+    SELECTOR = getattr(selectors, 'DevpollSelector', None)
+
+
+
 def test_main():
     tests = [DefaultSelectorTestCase, SelectSelectorTestCase,
              PollSelectorTestCase, EpollSelectorTestCase,
-             KqueueSelectorTestCase]
+             KqueueSelectorTestCase, DevpollSelectorTestCase]
     support.run_unittest(*tests)
     support.reap_children()
 
diff --git a/Lib/test/test_set.py b/Lib/test/test_set.py
index 65e424307f..c25386fad6 100644
--- a/Lib/test/test_set.py
+++ b/Lib/test/test_set.py
@@ -931,7 +931,7 @@ class TestBasicOpsString(TestBasicOps, unittest.TestCase):
 
 class TestBasicOpsBytes(TestBasicOps, unittest.TestCase):
     def setUp(self):
-        self.case   = "string set"
+        self.case   = "bytes set"
         self.values = [b"a", b"b", b"c"]
         self.set    = set(self.values)
         self.dup    = set(self.values)
diff --git a/Lib/test/test_shutil.py b/Lib/test/test_shutil.py
index 9325bc7dc1..c5545ba3b3 100644
--- a/Lib/test/test_shutil.py
+++ b/Lib/test/test_shutil.py
@@ -34,6 +34,12 @@ try:
 except ImportError:
     BZ2_SUPPORTED = False
 
+try:
+    import lzma
+    LZMA_SUPPORTED = True
+except ImportError:
+    LZMA_SUPPORTED = False
+
 TESTFN2 = TESTFN + "2"
 
 try:
@@ -1189,6 +1195,8 @@ class TestShutil(unittest.TestCase):
         formats = ['tar', 'gztar', 'zip']
         if BZ2_SUPPORTED:
             formats.append('bztar')
+        if LZMA_SUPPORTED:
+            formats.append('xztar')
 
         for format in formats:
             tmpdir = self.mkdtemp()
@@ -1625,6 +1633,24 @@ class TestMove(unittest.TestCase):
         rv = shutil.move(self.src_file, os.path.join(self.dst_dir, 'bar'))
         self.assertEqual(rv, os.path.join(self.dst_dir, 'bar'))
 
+    @mock_rename
+    def test_move_file_special_function(self):
+        moved = []
+        def _copy(src, dst):
+            moved.append((src, dst))
+        shutil.move(self.src_file, self.dst_dir, copy_function=_copy)
+        self.assertEqual(len(moved), 1)
+
+    @mock_rename
+    def test_move_dir_special_function(self):
+        moved = []
+        def _copy(src, dst):
+            moved.append((src, dst))
+        support.create_empty_file(os.path.join(self.src_dir, 'child'))
+        support.create_empty_file(os.path.join(self.src_dir, 'child1'))
+        shutil.move(self.src_dir, self.dst_dir, copy_function=_copy)
+        self.assertEqual(len(moved), 3)
+
 
 class TestCopyFile(unittest.TestCase):
 
diff --git a/Lib/test/test_signal.py b/Lib/test/test_signal.py
index 74f74af0b4..774fc809a1 100644
--- a/Lib/test/test_signal.py
+++ b/Lib/test/test_signal.py
@@ -1,10 +1,12 @@
 import unittest
 from test import support
 from contextlib import closing
+import enum
 import gc
 import pickle
 import select
 import signal
+import socket
 import struct
 import subprocess
 import traceback
@@ -14,6 +16,10 @@ try:
     import threading
 except ImportError:
     threading = None
+try:
+    import _testcapi
+except ImportError:
+    _testcapi = None
 
 
 class HandlerBCalled(Exception):
@@ -39,6 +45,23 @@ def ignoring_eintr(__func, *args, **kwargs):
         return None
 
 
+class GenericTests(unittest.TestCase):
+
+    @unittest.skipIf(threading is None, "test needs threading module")
+    def test_enums(self):
+        for name in dir(signal):
+            sig = getattr(signal, name)
+            if name in {'SIG_DFL', 'SIG_IGN'}:
+                self.assertIsInstance(sig, signal.Handlers)
+            elif name in {'SIG_BLOCK', 'SIG_UNBLOCK', 'SIG_SETMASK'}:
+                self.assertIsInstance(sig, signal.Sigmasks)
+            elif name.startswith('SIG') and not name.startswith('SIG_'):
+                self.assertIsInstance(sig, signal.Signals)
+            elif name.startswith('CTRL_'):
+                self.assertIsInstance(sig, signal.Signals)
+                self.assertEqual(sys.platform, "win32")
+
+
 @unittest.skipIf(sys.platform == "win32", "Not valid on Windows")
 class InterProcessSignalTests(unittest.TestCase):
     MAX_DURATION = 20   # Entire test should last at most 20 sec.
@@ -195,6 +218,7 @@ class PosixTests(unittest.TestCase):
 
     def test_getsignal(self):
         hup = signal.signal(signal.SIGHUP, self.trivial_signal_handler)
+        self.assertIsInstance(hup, signal.Handlers)
         self.assertEqual(signal.getsignal(signal.SIGHUP),
                          self.trivial_signal_handler)
         signal.signal(signal.SIGHUP, hup)
@@ -229,15 +253,77 @@ class WakeupFDTests(unittest.TestCase):
 
     def test_invalid_fd(self):
         fd = support.make_bad_fd()
-        self.assertRaises(ValueError, signal.set_wakeup_fd, fd)
+        self.assertRaises((ValueError, OSError),
+                          signal.set_wakeup_fd, fd)
+
+    def test_invalid_socket(self):
+        sock = socket.socket()
+        fd = sock.fileno()
+        sock.close()
+        self.assertRaises((ValueError, OSError),
+                          signal.set_wakeup_fd, fd)
+
+    def test_set_wakeup_fd_result(self):
+        r1, w1 = os.pipe()
+        self.addCleanup(os.close, r1)
+        self.addCleanup(os.close, w1)
+        r2, w2 = os.pipe()
+        self.addCleanup(os.close, r2)
+        self.addCleanup(os.close, w2)
+
+        if hasattr(os, 'set_blocking'):
+            os.set_blocking(w1, False)
+            os.set_blocking(w2, False)
+
+        signal.set_wakeup_fd(w1)
+        self.assertEqual(signal.set_wakeup_fd(w2), w1)
+        self.assertEqual(signal.set_wakeup_fd(-1), w2)
+        self.assertEqual(signal.set_wakeup_fd(-1), -1)
+
+    def test_set_wakeup_fd_socket_result(self):
+        sock1 = socket.socket()
+        self.addCleanup(sock1.close)
+        sock1.setblocking(False)
+        fd1 = sock1.fileno()
+
+        sock2 = socket.socket()
+        self.addCleanup(sock2.close)
+        sock2.setblocking(False)
+        fd2 = sock2.fileno()
+
+        signal.set_wakeup_fd(fd1)
+        self.assertEqual(signal.set_wakeup_fd(fd2), fd1)
+        self.assertEqual(signal.set_wakeup_fd(-1), fd2)
+        self.assertEqual(signal.set_wakeup_fd(-1), -1)
+
+    # On Windows, files are always blocking and Windows does not provide a
+    # function to test if a socket is in non-blocking mode.
+    @unittest.skipIf(sys.platform == "win32", "tests specific to POSIX")
+    def test_set_wakeup_fd_blocking(self):
+        rfd, wfd = os.pipe()
+        self.addCleanup(os.close, rfd)
+        self.addCleanup(os.close, wfd)
+
+        # fd must be non-blocking
+        os.set_blocking(wfd, True)
+        with self.assertRaises(ValueError) as cm:
+            signal.set_wakeup_fd(wfd)
+        self.assertEqual(str(cm.exception),
+                         "the fd %s must be in non-blocking mode" % wfd)
+
+        # non-blocking is ok
+        os.set_blocking(wfd, False)
+        signal.set_wakeup_fd(wfd)
+        signal.set_wakeup_fd(-1)
 
 
 @unittest.skipIf(sys.platform == "win32", "Not valid on Windows")
 class WakeupSignalTests(unittest.TestCase):
+    @unittest.skipIf(_testcapi is None, 'need _testcapi')
     def check_wakeup(self, test_body, *signals, ordered=True):
         # use a subprocess to have only one thread
         code = """if 1:
-        import fcntl
+        import _testcapi
         import os
         import signal
         import struct
@@ -260,10 +346,7 @@ class WakeupSignalTests(unittest.TestCase):
 
         signal.signal(signal.SIGALRM, handler)
         read, write = os.pipe()
-        for fd in (read, write):
-            flags = fcntl.fcntl(fd, fcntl.F_GETFL, 0)
-            flags = flags | os.O_NONBLOCK
-            fcntl.fcntl(fd, fcntl.F_SETFL, flags)
+        os.set_blocking(write, False)
         signal.set_wakeup_fd(write)
 
         test()
@@ -271,21 +354,21 @@ class WakeupSignalTests(unittest.TestCase):
 
         os.close(read)
         os.close(write)
-        """.format(signals, ordered, test_body)
+        """.format(tuple(map(int, signals)), ordered, test_body)
 
         assert_python_ok('-c', code)
 
+    @unittest.skipIf(_testcapi is None, 'need _testcapi')
     def test_wakeup_write_error(self):
         # Issue #16105: write() errors in the C signal handler should not
         # pass silently.
         # Use a subprocess to have only one thread.
         code = """if 1:
+        import _testcapi
         import errno
-        import fcntl
         import os
         import signal
         import sys
-        import time
         from test.support import captured_stderr
 
         def handler(signum, frame):
@@ -293,15 +376,13 @@ class WakeupSignalTests(unittest.TestCase):
 
         signal.signal(signal.SIGALRM, handler)
         r, w = os.pipe()
-        flags = fcntl.fcntl(r, fcntl.F_GETFL, 0)
-        fcntl.fcntl(r, fcntl.F_SETFL, flags | os.O_NONBLOCK)
+        os.set_blocking(r, False)
 
         # Set wakeup_fd a read-only file descriptor to trigger the error
         signal.set_wakeup_fd(r)
         try:
             with captured_stderr() as err:
-                signal.alarm(1)
-                time.sleep(5.0)
+                _testcapi.raise_signal(signal.SIGALRM)
         except ZeroDivisionError:
             # An ignored exception should have been printed out on stderr
             err = err.getvalue()
@@ -312,6 +393,9 @@ class WakeupSignalTests(unittest.TestCase):
                 raise AssertionError(err)
         else:
             raise AssertionError("ZeroDivisionError not raised")
+
+        os.close(r)
+        os.close(w)
         """
         r, w = os.pipe()
         try:
@@ -375,9 +459,10 @@ class WakeupSignalTests(unittest.TestCase):
 
     def test_signum(self):
         self.check_wakeup("""def test():
+            import _testcapi
             signal.signal(signal.SIGUSR1, handler)
-            os.kill(os.getpid(), signal.SIGUSR1)
-            os.kill(os.getpid(), signal.SIGALRM)
+            _testcapi.raise_signal(signal.SIGUSR1)
+            _testcapi.raise_signal(signal.SIGALRM)
         """, signal.SIGUSR1, signal.SIGALRM)
 
     @unittest.skipUnless(hasattr(signal, 'pthread_sigmask'),
@@ -391,13 +476,97 @@ class WakeupSignalTests(unittest.TestCase):
             signal.signal(signum2, handler)
 
             signal.pthread_sigmask(signal.SIG_BLOCK, (signum1, signum2))
-            os.kill(os.getpid(), signum1)
-            os.kill(os.getpid(), signum2)
+            _testcapi.raise_signal(signum1)
+            _testcapi.raise_signal(signum2)
             # Unblocking the 2 signals calls the C signal handler twice
             signal.pthread_sigmask(signal.SIG_UNBLOCK, (signum1, signum2))
         """,  signal.SIGUSR1, signal.SIGUSR2, ordered=False)
 
 
+@unittest.skipUnless(hasattr(socket, 'socketpair'), 'need socket.socketpair')
+class WakeupSocketSignalTests(unittest.TestCase):
+
+    @unittest.skipIf(_testcapi is None, 'need _testcapi')
+    def test_socket(self):
+        # use a subprocess to have only one thread
+        code = """if 1:
+        import signal
+        import socket
+        import struct
+        import _testcapi
+
+        signum = signal.SIGINT
+        signals = (signum,)
+
+        def handler(signum, frame):
+            pass
+
+        signal.signal(signum, handler)
+
+        read, write = socket.socketpair()
+        read.setblocking(False)
+        write.setblocking(False)
+        signal.set_wakeup_fd(write.fileno())
+
+        _testcapi.raise_signal(signum)
+
+        data = read.recv(1)
+        if not data:
+            raise Exception("no signum written")
+        raised = struct.unpack('B', data)
+        if raised != signals:
+            raise Exception("%r != %r" % (raised, signals))
+
+        read.close()
+        write.close()
+        """
+
+        assert_python_ok('-c', code)
+
+    @unittest.skipIf(_testcapi is None, 'need _testcapi')
+    def test_send_error(self):
+        # Use a subprocess to have only one thread.
+        if os.name == 'nt':
+            action = 'send'
+        else:
+            action = 'write'
+        code = """if 1:
+        import errno
+        import signal
+        import socket
+        import sys
+        import time
+        import _testcapi
+        from test.support import captured_stderr
+
+        signum = signal.SIGINT
+
+        def handler(signum, frame):
+            pass
+
+        signal.signal(signum, handler)
+
+        read, write = socket.socketpair()
+        read.setblocking(False)
+        write.setblocking(False)
+
+        signal.set_wakeup_fd(write.fileno())
+
+        # Close sockets: send() will fail
+        read.close()
+        write.close()
+
+        with captured_stderr() as err:
+            _testcapi.raise_signal(signum)
+
+        err = err.getvalue()
+        if ('Exception ignored when trying to {action} to the signal wakeup fd'
+            not in err):
+            raise AssertionError(err)
+        """.format(action=action)
+        assert_python_ok('-c', code)
+
+
 @unittest.skipIf(sys.platform == "win32", "Not valid on Windows")
 class SiginterruptTest(unittest.TestCase):
 
@@ -418,7 +587,7 @@ class SiginterruptTest(unittest.TestCase):
             r, w = os.pipe()
 
             def handler(signum, frame):
-                pass
+                1 / 0
 
             signal.signal(signal.SIGALRM, handler)
             if interrupt is not None:
@@ -428,18 +597,21 @@ class SiginterruptTest(unittest.TestCase):
             sys.stdout.flush()
 
             # run the test twice
-            for loop in range(2):
-                # send a SIGALRM in a second (during the read)
-                signal.alarm(1)
-                try:
-                    # blocking call: read from a pipe without data
-                    os.read(r, 1)
-                except OSError as err:
-                    if err.errno != errno.EINTR:
-                        raise
-                else:
-                    sys.exit(2)
-            sys.exit(3)
+            try:
+                for loop in range(2):
+                    # send a SIGALRM in a second (during the read)
+                    signal.alarm(1)
+                    try:
+                        # blocking call: read from a pipe without data
+                        os.read(r, 1)
+                    except ZeroDivisionError:
+                        pass
+                    else:
+                        sys.exit(2)
+                sys.exit(3)
+            finally:
+                os.close(r)
+                os.close(w)
         """ % (interrupt,)
         with spawn_python('-c', code) as process:
             try:
@@ -604,6 +776,8 @@ class PendingSignalsTests(unittest.TestCase):
             signal.pthread_sigmask(signal.SIG_BLOCK, [signum])
             os.kill(os.getpid(), signum)
             pending = signal.sigpending()
+            for sig in pending:
+                assert isinstance(sig, signal.Signals), repr(pending)
             if pending != {signum}:
                 raise Exception('%s != {%s}' % (pending, signum))
             try:
@@ -660,6 +834,7 @@ class PendingSignalsTests(unittest.TestCase):
         code = '''if 1:
         import signal
         import sys
+        from signal import Signals
 
         def handler(signum, frame):
             1/0
@@ -702,6 +877,7 @@ class PendingSignalsTests(unittest.TestCase):
         def test(signum):
             signal.alarm(1)
             received = signal.sigwait([signum])
+            assert isinstance(received, signal.Signals), received
             if received != signum:
                 raise Exception('received %s, not %s' % (received, signum))
         ''')
@@ -842,8 +1018,14 @@ class PendingSignalsTests(unittest.TestCase):
         def kill(signum):
             os.kill(os.getpid(), signum)
 
+        def check_mask(mask):
+            for sig in mask:
+                assert isinstance(sig, signal.Signals), repr(sig)
+
         def read_sigmask():
-            return signal.pthread_sigmask(signal.SIG_BLOCK, [])
+            sigmask = signal.pthread_sigmask(signal.SIG_BLOCK, [])
+            check_mask(sigmask)
+            return sigmask
 
         signum = signal.SIGUSR1
 
@@ -852,6 +1034,7 @@ class PendingSignalsTests(unittest.TestCase):
 
         # Unblock SIGUSR1 (and copy the old mask) to test our signal handler
         old_mask = signal.pthread_sigmask(signal.SIG_UNBLOCK, [signum])
+        check_mask(old_mask)
         try:
             kill(signum)
         except ZeroDivisionError:
@@ -861,11 +1044,13 @@ class PendingSignalsTests(unittest.TestCase):
 
         # Block and then raise SIGUSR1. The signal is blocked: the signal
         # handler is not called, and the signal is now pending
-        signal.pthread_sigmask(signal.SIG_BLOCK, [signum])
+        mask = signal.pthread_sigmask(signal.SIG_BLOCK, [signum])
+        check_mask(mask)
         kill(signum)
 
         # Check the new mask
         blocked = read_sigmask()
+        check_mask(blocked)
         if signum not in blocked:
             raise Exception("%s not in %s" % (signum, blocked))
         if old_mask ^ blocked != {signum}:
@@ -928,8 +1113,9 @@ class PendingSignalsTests(unittest.TestCase):
 
 def test_main():
     try:
-        support.run_unittest(PosixTests, InterProcessSignalTests,
+        support.run_unittest(GenericTests, PosixTests, InterProcessSignalTests,
                              WakeupFDTests, WakeupSignalTests,
+                             WakeupSocketSignalTests,
                              SiginterruptTest, ItimerTest, WindowsSignalTests,
                              PendingSignalsTests)
     finally:
diff --git a/Lib/test/test_site.py b/Lib/test/test_site.py
index f71cf73330..e234164b37 100644
--- a/Lib/test/test_site.py
+++ b/Lib/test/test_site.py
@@ -147,7 +147,7 @@ class HelperFunctionsTests(unittest.TestCase):
             re.escape(os.path.join(pth_dir, pth_fn)))
         # XXX: ditto previous XXX comment.
         self.assertRegex(err_out.getvalue(), 'Traceback')
-        self.assertRegex(err_out.getvalue(), 'TypeError')
+        self.assertRegex(err_out.getvalue(), 'ValueError')
 
     def test_addsitedir(self):
         # Same tests for test_addpackage since addsitedir() essentially just
@@ -235,20 +235,18 @@ class HelperFunctionsTests(unittest.TestCase):
             # OS X framework builds
             site.PREFIXES = ['Python.framework']
             dirs = site.getsitepackages()
-            self.assertEqual(len(dirs), 3)
+            self.assertEqual(len(dirs), 2)
             wanted = os.path.join('/Library',
                                   sysconfig.get_config_var("PYTHONFRAMEWORK"),
                                   sys.version[:3],
                                   'site-packages')
-            self.assertEqual(dirs[2], wanted)
+            self.assertEqual(dirs[1], wanted)
         elif os.sep == '/':
             # OS X non-framwework builds, Linux, FreeBSD, etc
-            self.assertEqual(len(dirs), 2)
+            self.assertEqual(len(dirs), 1)
             wanted = os.path.join('xoxo', 'lib', 'python' + sys.version[:3],
                                   'site-packages')
             self.assertEqual(dirs[0], wanted)
-            wanted = os.path.join('xoxo', 'lib', 'site-python')
-            self.assertEqual(dirs[1], wanted)
         else:
             # other platforms
             self.assertEqual(len(dirs), 2)
diff --git a/Lib/test/test_smtpd.py b/Lib/test/test_smtpd.py
index 93f14c4562..6eb47f1dee 100644
--- a/Lib/test/test_smtpd.py
+++ b/Lib/test/test_smtpd.py
@@ -1,4 +1,5 @@
 import unittest
+import textwrap
 from test import support, mock_socket
 import socket
 import io
@@ -7,15 +8,22 @@ import asyncore
 
 
 class DummyServer(smtpd.SMTPServer):
-    def __init__(self, localaddr, remoteaddr):
-        smtpd.SMTPServer.__init__(self, localaddr, remoteaddr)
+    def __init__(self, *args, **kwargs):
+        smtpd.SMTPServer.__init__(self, *args, **kwargs)
         self.messages = []
+        if self._decode_data:
+            self.return_status = 'return status'
+        else:
+            self.return_status = b'return status'
 
     def process_message(self, peer, mailfrom, rcpttos, data):
         self.messages.append((peer, mailfrom, rcpttos, data))
-        if data == 'return status':
+        if data == self.return_status:
             return '250 Okish'
 
+    def process_smtputf8_message(self, *args, **kwargs):
+        return '250 SMTPUTF8 message okish'
+
 
 class DummyDispatcherBroken(Exception):
     pass
@@ -31,9 +39,10 @@ class SMTPDServerTest(unittest.TestCase):
         smtpd.socket = asyncore.socket = mock_socket
 
     def test_process_message_unimplemented(self):
-        server = smtpd.SMTPServer('a', 'b')
+        server = smtpd.SMTPServer((support.HOST, 0), ('b', 0),
+                                  decode_data=True)
         conn, addr = server.accept()
-        channel = smtpd.SMTPChannel(server, conn, addr)
+        channel = smtpd.SMTPChannel(server, conn, addr, decode_data=True)
 
         def write_line(line):
             channel.socket.queue_recv(line)
@@ -45,19 +54,163 @@ class SMTPDServerTest(unittest.TestCase):
         write_line(b'DATA')
         self.assertRaises(NotImplementedError, write_line, b'spam\r\n.\r\n')
 
+    def test_process_smtputf8_message_unimplemented(self):
+        server = smtpd.SMTPServer((support.HOST, 0), ('b', 0),
+                                  enable_SMTPUTF8=True)
+        conn, addr = server.accept()
+        channel = smtpd.SMTPChannel(server, conn, addr, enable_SMTPUTF8=True)
+
+        def write_line(line):
+            channel.socket.queue_recv(line)
+            channel.handle_read()
+
+        write_line(b'EHLO example')
+        write_line(b'MAIL From: <eggs@example> BODY=8BITMIME SMTPUTF8')
+        write_line(b'RCPT To: <spam@example>')
+        write_line(b'DATA')
+        self.assertRaises(NotImplementedError, write_line, b'spam\r\n.\r\n')
+
+    def test_decode_data_default_warns(self):
+        with self.assertWarns(DeprecationWarning):
+            smtpd.SMTPServer((support.HOST, 0), ('b', 0))
+
+    def test_decode_data_and_enable_SMTPUTF8_raises(self):
+        self.assertRaises(
+            ValueError,
+            smtpd.SMTPServer,
+            (support.HOST, 0),
+            ('b', 0),
+            enable_SMTPUTF8=True,
+            decode_data=True)
+
+    def tearDown(self):
+        asyncore.close_all()
+        asyncore.socket = smtpd.socket = socket
+
+
+class DebuggingServerTest(unittest.TestCase):
+
+    def setUp(self):
+        smtpd.socket = asyncore.socket = mock_socket
+
+    def send_data(self, channel, data, enable_SMTPUTF8=False):
+        def write_line(line):
+            channel.socket.queue_recv(line)
+            channel.handle_read()
+        write_line(b'EHLO example')
+        if enable_SMTPUTF8:
+            write_line(b'MAIL From:eggs@example BODY=8BITMIME SMTPUTF8')
+        else:
+            write_line(b'MAIL From:eggs@example')
+        write_line(b'RCPT To:spam@example')
+        write_line(b'DATA')
+        write_line(data)
+        write_line(b'.')
+
+    def test_process_message_with_decode_data_true(self):
+        server = smtpd.DebuggingServer((support.HOST, 0), ('b', 0),
+                                       decode_data=True)
+        conn, addr = server.accept()
+        channel = smtpd.SMTPChannel(server, conn, addr, decode_data=True)
+        with support.captured_stdout() as s:
+            self.send_data(channel, b'From: test\n\nhello\n')
+        stdout = s.getvalue()
+        self.assertEqual(stdout, textwrap.dedent("""\
+             ---------- MESSAGE FOLLOWS ----------
+             From: test
+             X-Peer: peer-address
+
+             hello
+             ------------ END MESSAGE ------------
+             """))
+
+    def test_process_message_with_decode_data_false(self):
+        server = smtpd.DebuggingServer((support.HOST, 0), ('b', 0),
+                                       decode_data=False)
+        conn, addr = server.accept()
+        channel = smtpd.SMTPChannel(server, conn, addr, decode_data=False)
+        with support.captured_stdout() as s:
+            self.send_data(channel, b'From: test\n\nh\xc3\xa9llo\xff\n')
+        stdout = s.getvalue()
+        self.assertEqual(stdout, textwrap.dedent("""\
+             ---------- MESSAGE FOLLOWS ----------
+             b'From: test'
+             b'X-Peer: peer-address'
+             b''
+             b'h\\xc3\\xa9llo\\xff'
+             ------------ END MESSAGE ------------
+             """))
+
+    def test_process_message_with_enable_SMTPUTF8_true(self):
+        server = smtpd.DebuggingServer((support.HOST, 0), ('b', 0),
+                                       enable_SMTPUTF8=True)
+        conn, addr = server.accept()
+        channel = smtpd.SMTPChannel(server, conn, addr, enable_SMTPUTF8=True)
+        with support.captured_stdout() as s:
+            self.send_data(channel, b'From: test\n\nh\xc3\xa9llo\xff\n')
+        stdout = s.getvalue()
+        self.assertEqual(stdout, textwrap.dedent("""\
+             ---------- MESSAGE FOLLOWS ----------
+             b'From: test'
+             b'X-Peer: peer-address'
+             b''
+             b'h\\xc3\\xa9llo\\xff'
+             ------------ END MESSAGE ------------
+             """))
+
+    def test_process_SMTPUTF8_message_with_enable_SMTPUTF8_true(self):
+        server = smtpd.DebuggingServer((support.HOST, 0), ('b', 0),
+                                       enable_SMTPUTF8=True)
+        conn, addr = server.accept()
+        channel = smtpd.SMTPChannel(server, conn, addr, enable_SMTPUTF8=True)
+        with support.captured_stdout() as s:
+            self.send_data(channel, b'From: test\n\nh\xc3\xa9llo\xff\n',
+                           enable_SMTPUTF8=True)
+        stdout = s.getvalue()
+        self.assertEqual(stdout, textwrap.dedent("""\
+             ----- SMTPUTF8 MESSAGE FOLLOWS ------
+             b'From: test'
+             b'X-Peer: peer-address'
+             b''
+             b'h\\xc3\\xa9llo\\xff'
+             ------------ END MESSAGE ------------
+             """))
+
     def tearDown(self):
         asyncore.close_all()
         asyncore.socket = smtpd.socket = socket
 
 
+class TestFamilyDetection(unittest.TestCase):
+    def setUp(self):
+        smtpd.socket = asyncore.socket = mock_socket
+
+    def tearDown(self):
+        asyncore.close_all()
+        asyncore.socket = smtpd.socket = socket
+
+    @unittest.skipUnless(support.IPV6_ENABLED, "IPv6 not enabled")
+    def test_socket_uses_IPv6(self):
+        server = smtpd.SMTPServer((support.HOSTv6, 0), (support.HOST, 0),
+                                  decode_data=False)
+        self.assertEqual(server.socket.family, socket.AF_INET6)
+
+    def test_socket_uses_IPv4(self):
+        server = smtpd.SMTPServer((support.HOST, 0), (support.HOSTv6, 0),
+                                  decode_data=False)
+        self.assertEqual(server.socket.family, socket.AF_INET)
+
+
 class SMTPDChannelTest(unittest.TestCase):
     def setUp(self):
         smtpd.socket = asyncore.socket = mock_socket
         self.old_debugstream = smtpd.DEBUGSTREAM
         self.debug = smtpd.DEBUGSTREAM = io.StringIO()
-        self.server = DummyServer('a', 'b')
+        self.server = DummyServer((support.HOST, 0), ('b', 0),
+                                  decode_data=True)
         conn, addr = self.server.accept()
-        self.channel = smtpd.SMTPChannel(self.server, conn, addr)
+        self.channel = smtpd.SMTPChannel(self.server, conn, addr,
+                                         decode_data=True)
 
     def tearDown(self):
         asyncore.close_all()
@@ -69,7 +222,9 @@ class SMTPDChannelTest(unittest.TestCase):
         self.channel.handle_read()
 
     def test_broken_connect(self):
-        self.assertRaises(DummyDispatcherBroken, BrokenDummyServer, 'a', 'b')
+        self.assertRaises(
+            DummyDispatcherBroken, BrokenDummyServer,
+            (support.HOST, 0), ('b', 0), decode_data=True)
 
     def test_server_accept(self):
         self.server.handle_accept()
@@ -214,6 +369,12 @@ class SMTPDChannelTest(unittest.TestCase):
         self.assertEqual(self.channel.socket.last,
                          b'500 Error: line too long\r\n')
 
+    def test_MAIL_command_rejects_SMTPUTF8_by_default(self):
+        self.write_line(b'EHLO example')
+        self.write_line(
+            b'MAIL from: <naive@example.com> BODY=8BITMIME SMTPUTF8')
+        self.assertEqual(self.channel.socket.last[0:1], b'5')
+
     def test_data_longer_than_default_data_size_limit(self):
         # Hack the default so we don't have to generate so much data.
         self.channel.data_size_limit = 1048
@@ -387,7 +548,10 @@ class SMTPDChannelTest(unittest.TestCase):
         self.write_line(b'data\r\nmore\r\n.')
         self.assertEqual(self.channel.socket.last, b'250 OK\r\n')
         self.assertEqual(self.server.messages,
-            [('peer', 'eggs@example', ['spam@example'], 'data\nmore')])
+            [(('peer-address', 'peer-port'),
+              'eggs@example',
+              ['spam@example'],
+              'data\nmore')])
 
     def test_DATA_syntax(self):
         self.write_line(b'HELO example')
@@ -417,7 +581,10 @@ class SMTPDChannelTest(unittest.TestCase):
         self.write_line(b'DATA')
         self.write_line(b'data\r\n.')
         self.assertEqual(self.server.messages,
-            [('peer', 'eggs@example', ['spam@example','ham@example'], 'data')])
+            [(('peer-address', 'peer-port'),
+              'eggs@example',
+              ['spam@example','ham@example'],
+              'data')])
 
     def test_manual_status(self):
         # checks that the Channel is able to return a custom status message
@@ -439,7 +606,10 @@ class SMTPDChannelTest(unittest.TestCase):
         self.write_line(b'DATA')
         self.write_line(b'data\r\n.')
         self.assertEqual(self.server.messages,
-            [('peer', 'foo@example', ['eggs@example'], 'data')])
+            [(('peer-address', 'peer-port'),
+               'foo@example',
+               ['eggs@example'],
+               'data')])
 
     def test_HELO_RSET(self):
         self.write_line(b'HELO example')
@@ -502,6 +672,24 @@ class SMTPDChannelTest(unittest.TestCase):
         with support.check_warnings(('', DeprecationWarning)):
             self.channel._SMTPChannel__addr = 'spam'
 
+    def test_decode_data_default_warning(self):
+        with self.assertWarns(DeprecationWarning):
+            server = DummyServer((support.HOST, 0), ('b', 0))
+        conn, addr = self.server.accept()
+        with self.assertWarns(DeprecationWarning):
+            smtpd.SMTPChannel(server, conn, addr)
+
+@unittest.skipUnless(support.IPV6_ENABLED, "IPv6 not enabled")
+class SMTPDChannelIPv6Test(SMTPDChannelTest):
+    def setUp(self):
+        smtpd.socket = asyncore.socket = mock_socket
+        self.old_debugstream = smtpd.DEBUGSTREAM
+        self.debug = smtpd.DEBUGSTREAM = io.StringIO()
+        self.server = DummyServer((support.HOSTv6, 0), ('b', 0),
+                                  decode_data=True)
+        conn, addr = self.server.accept()
+        self.channel = smtpd.SMTPChannel(self.server, conn, addr,
+                                         decode_data=True)
 
 class SMTPDChannelWithDataSizeLimitTest(unittest.TestCase):
 
@@ -509,10 +697,12 @@ class SMTPDChannelWithDataSizeLimitTest(unittest.TestCase):
         smtpd.socket = asyncore.socket = mock_socket
         self.old_debugstream = smtpd.DEBUGSTREAM
         self.debug = smtpd.DEBUGSTREAM = io.StringIO()
-        self.server = DummyServer('a', 'b')
+        self.server = DummyServer((support.HOST, 0), ('b', 0),
+                                  decode_data=True)
         conn, addr = self.server.accept()
         # Set DATA size limit to 32 bytes for easy testing
-        self.channel = smtpd.SMTPChannel(self.server, conn, addr, 32)
+        self.channel = smtpd.SMTPChannel(self.server, conn, addr, 32,
+                                         decode_data=True)
 
     def tearDown(self):
         asyncore.close_all()
@@ -536,7 +726,10 @@ class SMTPDChannelWithDataSizeLimitTest(unittest.TestCase):
         self.write_line(b'data\r\nmore\r\n.')
         self.assertEqual(self.channel.socket.last, b'250 OK\r\n')
         self.assertEqual(self.server.messages,
-            [('peer', 'eggs@example', ['spam@example'], 'data\nmore')])
+            [(('peer-address', 'peer-port'),
+              'eggs@example',
+              ['spam@example'],
+              'data\nmore')])
 
     def test_data_limit_dialog_too_much_data(self):
         self.write_line(b'HELO example')
@@ -553,5 +746,181 @@ class SMTPDChannelWithDataSizeLimitTest(unittest.TestCase):
                          b'552 Error: Too much mail data\r\n')
 
 
+class SMTPDChannelWithDecodeDataFalse(unittest.TestCase):
+
+    def setUp(self):
+        smtpd.socket = asyncore.socket = mock_socket
+        self.old_debugstream = smtpd.DEBUGSTREAM
+        self.debug = smtpd.DEBUGSTREAM = io.StringIO()
+        self.server = DummyServer((support.HOST, 0), ('b', 0),
+                                  decode_data=False)
+        conn, addr = self.server.accept()
+        # Set decode_data to False
+        self.channel = smtpd.SMTPChannel(self.server, conn, addr,
+                decode_data=False)
+
+    def tearDown(self):
+        asyncore.close_all()
+        asyncore.socket = smtpd.socket = socket
+        smtpd.DEBUGSTREAM = self.old_debugstream
+
+    def write_line(self, line):
+        self.channel.socket.queue_recv(line)
+        self.channel.handle_read()
+
+    def test_ascii_data(self):
+        self.write_line(b'HELO example')
+        self.write_line(b'MAIL From:eggs@example')
+        self.write_line(b'RCPT To:spam@example')
+        self.write_line(b'DATA')
+        self.write_line(b'plain ascii text')
+        self.write_line(b'.')
+        self.assertEqual(self.channel.received_data, b'plain ascii text')
+
+    def test_utf8_data(self):
+        self.write_line(b'HELO example')
+        self.write_line(b'MAIL From:eggs@example')
+        self.write_line(b'RCPT To:spam@example')
+        self.write_line(b'DATA')
+        self.write_line(b'utf8 enriched text: \xc5\xbc\xc5\xba\xc4\x87')
+        self.write_line(b'and some plain ascii')
+        self.write_line(b'.')
+        self.assertEqual(
+            self.channel.received_data,
+            b'utf8 enriched text: \xc5\xbc\xc5\xba\xc4\x87\n'
+                b'and some plain ascii')
+
+
+class SMTPDChannelWithDecodeDataTrue(unittest.TestCase):
+
+    def setUp(self):
+        smtpd.socket = asyncore.socket = mock_socket
+        self.old_debugstream = smtpd.DEBUGSTREAM
+        self.debug = smtpd.DEBUGSTREAM = io.StringIO()
+        self.server = DummyServer((support.HOST, 0), ('b', 0),
+                                  decode_data=True)
+        conn, addr = self.server.accept()
+        # Set decode_data to True
+        self.channel = smtpd.SMTPChannel(self.server, conn, addr,
+                decode_data=True)
+
+    def tearDown(self):
+        asyncore.close_all()
+        asyncore.socket = smtpd.socket = socket
+        smtpd.DEBUGSTREAM = self.old_debugstream
+
+    def write_line(self, line):
+        self.channel.socket.queue_recv(line)
+        self.channel.handle_read()
+
+    def test_ascii_data(self):
+        self.write_line(b'HELO example')
+        self.write_line(b'MAIL From:eggs@example')
+        self.write_line(b'RCPT To:spam@example')
+        self.write_line(b'DATA')
+        self.write_line(b'plain ascii text')
+        self.write_line(b'.')
+        self.assertEqual(self.channel.received_data, 'plain ascii text')
+
+    def test_utf8_data(self):
+        self.write_line(b'HELO example')
+        self.write_line(b'MAIL From:eggs@example')
+        self.write_line(b'RCPT To:spam@example')
+        self.write_line(b'DATA')
+        self.write_line(b'utf8 enriched text: \xc5\xbc\xc5\xba\xc4\x87')
+        self.write_line(b'and some plain ascii')
+        self.write_line(b'.')
+        self.assertEqual(
+            self.channel.received_data,
+            'utf8 enriched text: żźć\nand some plain ascii')
+
+
+class SMTPDChannelTestWithEnableSMTPUTF8True(unittest.TestCase):
+    def setUp(self):
+        smtpd.socket = asyncore.socket = mock_socket
+        self.old_debugstream = smtpd.DEBUGSTREAM
+        self.debug = smtpd.DEBUGSTREAM = io.StringIO()
+        self.server = DummyServer((support.HOST, 0), ('b', 0),
+                                  enable_SMTPUTF8=True)
+        conn, addr = self.server.accept()
+        self.channel = smtpd.SMTPChannel(self.server, conn, addr,
+                                         enable_SMTPUTF8=True)
+
+    def tearDown(self):
+        asyncore.close_all()
+        asyncore.socket = smtpd.socket = socket
+        smtpd.DEBUGSTREAM = self.old_debugstream
+
+    def write_line(self, line):
+        self.channel.socket.queue_recv(line)
+        self.channel.handle_read()
+
+    def test_MAIL_command_accepts_SMTPUTF8_when_announced(self):
+        self.write_line(b'EHLO example')
+        self.write_line(
+            'MAIL from: <naïve@example.com> BODY=8BITMIME SMTPUTF8'.encode(
+                'utf-8')
+        )
+        self.assertEqual(self.channel.socket.last, b'250 OK\r\n')
+
+    def test_process_smtputf8_message(self):
+        self.write_line(b'EHLO example')
+        for mail_parameters in [b'', b'BODY=8BITMIME SMTPUTF8']:
+            self.write_line(b'MAIL from: <a@example> ' + mail_parameters)
+            self.assertEqual(self.channel.socket.last[0:3], b'250')
+            self.write_line(b'rcpt to:<b@example.com>')
+            self.assertEqual(self.channel.socket.last[0:3], b'250')
+            self.write_line(b'data')
+            self.assertEqual(self.channel.socket.last[0:3], b'354')
+            self.write_line(b'c\r\n.')
+            if mail_parameters == b'':
+                self.assertEqual(self.channel.socket.last, b'250 OK\r\n')
+            else:
+                self.assertEqual(self.channel.socket.last,
+                                 b'250 SMTPUTF8 message okish\r\n')
+
+    def test_utf8_data(self):
+        self.write_line(b'EHLO example')
+        self.write_line(
+            'MAIL From: naïve@examplé BODY=8BITMIME SMTPUTF8'.encode('utf-8'))
+        self.assertEqual(self.channel.socket.last[0:3], b'250')
+        self.write_line('RCPT To:späm@examplé'.encode('utf-8'))
+        self.assertEqual(self.channel.socket.last[0:3], b'250')
+        self.write_line(b'DATA')
+        self.assertEqual(self.channel.socket.last[0:3], b'354')
+        self.write_line(b'utf8 enriched text: \xc5\xbc\xc5\xba\xc4\x87')
+        self.write_line(b'.')
+        self.assertEqual(
+            self.channel.received_data,
+            b'utf8 enriched text: \xc5\xbc\xc5\xba\xc4\x87')
+
+    def test_MAIL_command_limit_extended_with_SIZE_and_SMTPUTF8(self):
+        self.write_line(b'ehlo example')
+        fill_len = (512 + 26 + 10) - len('mail from:<@example>')
+        self.write_line(b'MAIL from:<' +
+                        b'a' * (fill_len + 1) +
+                        b'@example>')
+        self.assertEqual(self.channel.socket.last,
+                         b'500 Error: line too long\r\n')
+        self.write_line(b'MAIL from:<' +
+                        b'a' * fill_len +
+                        b'@example>')
+        self.assertEqual(self.channel.socket.last, b'250 OK\r\n')
+
+    def test_multiple_emails_with_extended_command_length(self):
+        self.write_line(b'ehlo example')
+        fill_len = (512 + 26 + 10) - len('mail from:<@example>')
+        for char in [b'a', b'b', b'c']:
+            self.write_line(b'MAIL from:<' + char * fill_len + b'a@example>')
+            self.assertEqual(self.channel.socket.last[0:3], b'500')
+            self.write_line(b'MAIL from:<' + char * fill_len + b'@example>')
+            self.assertEqual(self.channel.socket.last[0:3], b'250')
+            self.write_line(b'rcpt to:<hans@example.com>')
+            self.assertEqual(self.channel.socket.last[0:3], b'250')
+            self.write_line(b'data')
+            self.assertEqual(self.channel.socket.last[0:3], b'354')
+            self.write_line(b'test\r\n.')
+            self.assertEqual(self.channel.socket.last[0:3], b'250')
+
 if __name__ == "__main__":
     unittest.main()
diff --git a/Lib/test/test_smtplib.py b/Lib/test/test_smtplib.py
index 95a9dbe912..5f12d28eea 100644
--- a/Lib/test/test_smtplib.py
+++ b/Lib/test/test_smtplib.py
@@ -10,6 +10,7 @@ import sys
 import time
 import select
 import errno
+import base64
 
 import unittest
 from test import support, mock_socket
@@ -30,7 +31,7 @@ if sys.platform == 'darwin':
 
 
 def server(evt, buf, serv):
-    serv.listen(5)
+    serv.listen()
     evt.set()
     try:
         conn, addr = serv.accept()
@@ -184,7 +185,8 @@ class DebuggingServerTests(unittest.TestCase):
         self.old_DEBUGSTREAM = smtpd.DEBUGSTREAM
         smtpd.DEBUGSTREAM = io.StringIO()
         # Pick a random unused port by passing 0 for the port number
-        self.serv = smtpd.DebuggingServer((HOST, 0), ('nowhere', -1))
+        self.serv = smtpd.DebuggingServer((HOST, 0), ('nowhere', -1),
+                                          decode_data=True)
         # Keep a note of what port was assigned
         self.port = self.serv.socket.getsockname()[1]
         serv_args = (self.serv, self.serv_evt, self.client_evt)
@@ -604,7 +606,8 @@ sim_auth_credentials = {
     'cram-md5': ('TXIUQUBZB21LD2HLCMUUY29TIDG4OWQ0MJ'
                  'KWZGQ4ODNMNDA4NTGXMDRLZWMYZJDMODG1'),
     }
-sim_auth_login_password = 'C29TZXBHC3N3B3JK'
+sim_auth_login_user = 'TXIUQUBZB21LD2HLCMUUY29T'
+sim_auth_plain = 'AE1YLKFAC29TZXDOZXJLLMNVBQBZB21LCGFZC3DVCMQ='
 
 sim_lists = {'list-1':['Mr.A@somewhere.com','Mrs.C@somewhereesle.com'],
              'list-2':['Ms.B@xn--fo-fka.com',],
@@ -658,18 +661,16 @@ class SimSMTPChannel(smtpd.SMTPChannel):
             self.push('550 No access for you!')
 
     def smtp_AUTH(self, arg):
-        if arg.strip().lower()=='cram-md5':
+        mech = arg.strip().lower()
+        if mech=='cram-md5':
             self.push('334 {}'.format(sim_cram_md5_challenge))
-            return
-        mech, auth = arg.split()
-        mech = mech.lower()
-        if mech not in sim_auth_credentials:
+        elif mech not in sim_auth_credentials:
             self.push('504 auth type unimplemented')
             return
-        if mech == 'plain' and auth==sim_auth_credentials['plain']:
-            self.push('235 plain auth ok')
-        elif mech=='login' and auth==sim_auth_credentials['login']:
-            self.push('334 Password:')
+        elif mech=='plain':
+            self.push('334 ')
+        elif mech=='login':
+            self.push('334 ')
         else:
             self.push('550 No access for you!')
 
@@ -719,7 +720,8 @@ class SimSMTPServer(smtpd.SMTPServer):
 
     def handle_accepted(self, conn, addr):
         self._SMTPchannel = self.channel_class(
-            self._extra_features, self, conn, addr)
+            self._extra_features, self, conn, addr,
+            decode_data=self._decode_data)
 
     def process_message(self, peer, mailfrom, rcpttos, data):
         pass
@@ -742,7 +744,7 @@ class SMTPSimTests(unittest.TestCase):
         self.serv_evt = threading.Event()
         self.client_evt = threading.Event()
         # Pick a random unused port by passing 0 for the port number
-        self.serv = SimSMTPServer((HOST, 0), ('nowhere', -1))
+        self.serv = SimSMTPServer((HOST, 0), ('nowhere', -1), decode_data=True)
         # Keep a note of what port was assigned
         self.port = self.serv.socket.getsockname()[1]
         serv_args = (self.serv, self.serv_evt, self.client_evt)
@@ -816,28 +818,28 @@ class SMTPSimTests(unittest.TestCase):
         self.assertEqual(smtp.expn(u), expected_unknown)
         smtp.quit()
 
-    def testAUTH_PLAIN(self):
-        self.serv.add_feature("AUTH PLAIN")
-        smtp = smtplib.SMTP(HOST, self.port, local_hostname='localhost', timeout=15)
-
-        expected_auth_ok = (235, b'plain auth ok')
-        self.assertEqual(smtp.login(sim_auth[0], sim_auth[1]), expected_auth_ok)
-        smtp.close()
-
-    # SimSMTPChannel doesn't fully support LOGIN or CRAM-MD5 auth because they
-    # require a synchronous read to obtain the credentials...so instead smtpd
+    # SimSMTPChannel doesn't fully support AUTH because it requires a
+    # synchronous read to obtain the credentials...so instead smtpd
     # sees the credential sent by smtplib's login method as an unknown command,
     # which results in smtplib raising an auth error.  Fortunately the error
     # message contains the encoded credential, so we can partially check that it
     # was generated correctly (partially, because the 'word' is uppercased in
     # the error message).
 
+    def testAUTH_PLAIN(self):
+        self.serv.add_feature("AUTH PLAIN")
+        smtp = smtplib.SMTP(HOST, self.port, local_hostname='localhost', timeout=15)
+        try: smtp.login(sim_auth[0], sim_auth[1])
+        except smtplib.SMTPAuthenticationError as err:
+            self.assertIn(sim_auth_plain, str(err))
+        smtp.close()
+
     def testAUTH_LOGIN(self):
         self.serv.add_feature("AUTH LOGIN")
         smtp = smtplib.SMTP(HOST, self.port, local_hostname='localhost', timeout=15)
         try: smtp.login(sim_auth[0], sim_auth[1])
         except smtplib.SMTPAuthenticationError as err:
-            self.assertIn(sim_auth_login_password, str(err))
+            self.assertIn(sim_auth_login_user, str(err))
         smtp.close()
 
     def testAUTH_CRAM_MD5(self):
@@ -855,7 +857,23 @@ class SMTPSimTests(unittest.TestCase):
         smtp = smtplib.SMTP(HOST, self.port, local_hostname='localhost', timeout=15)
         try: smtp.login(sim_auth[0], sim_auth[1])
         except smtplib.SMTPAuthenticationError as err:
-            self.assertIn(sim_auth_login_password, str(err))
+            self.assertIn(sim_auth_login_user, str(err))
+        smtp.close()
+
+    def test_auth_function(self):
+        smtp = smtplib.SMTP(HOST, self.port,
+                            local_hostname='localhost', timeout=15)
+        self.serv.add_feature("AUTH CRAM-MD5")
+        smtp.user, smtp.password = sim_auth[0], sim_auth[1]
+        supported = {'CRAM-MD5': smtp.auth_cram_md5,
+                     'PLAIN': smtp.auth_plain,
+                     'LOGIN': smtp.auth_login,
+                    }
+        for mechanism, method in supported.items():
+            try: smtp.auth(mechanism, method)
+            except smtplib.SMTPAuthenticationError as err:
+                self.assertIn(sim_auth_credentials[mechanism.lower()].upper(),
+                              str(err))
         smtp.close()
 
     def test_quit_resets_greeting(self):
diff --git a/Lib/test/test_sndhdr.py b/Lib/test/test_sndhdr.py
index 5e0abe0b36..426417c038 100644
--- a/Lib/test/test_sndhdr.py
+++ b/Lib/test/test_sndhdr.py
@@ -1,4 +1,5 @@
 import sndhdr
+import pickle
 import unittest
 from test.support import findfile
 
@@ -18,6 +19,19 @@ class TestFormats(unittest.TestCase):
             what = sndhdr.what(filename)
             self.assertNotEqual(what, None, filename)
             self.assertSequenceEqual(what, expected)
+            self.assertEqual(what.filetype, expected[0])
+            self.assertEqual(what.framerate, expected[1])
+            self.assertEqual(what.nchannels, expected[2])
+            self.assertEqual(what.nframes, expected[3])
+            self.assertEqual(what.sampwidth, expected[4])
+
+    def test_pickleable(self):
+        filename = findfile('sndhdr.aifc', subdir="sndhdrdata")
+        what = sndhdr.what(filename)
+        for proto in range(pickle.HIGHEST_PROTOCOL + 1):
+            dump = pickle.dumps(what, proto)
+            self.assertEqual(pickle.loads(dump), what)
+
 
 if __name__ == '__main__':
     unittest.main()
diff --git a/Lib/test/test_socket.py b/Lib/test/test_socket.py
index b412386c43..cf45b7346c 100644
--- a/Lib/test/test_socket.py
+++ b/Lib/test/test_socket.py
@@ -20,6 +20,8 @@ import signal
 import math
 import pickle
 import struct
+import random
+import string
 try:
     import multiprocessing
 except ImportError:
@@ -76,7 +78,7 @@ class SocketTCPTest(unittest.TestCase):
     def setUp(self):
         self.serv = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
         self.port = support.bind_port(self.serv)
-        self.serv.listen(1)
+        self.serv.listen()
 
     def tearDown(self):
         self.serv.close()
@@ -445,7 +447,7 @@ class SocketListeningTestMixin(SocketTestBase):
 
     def setUp(self):
         super().setUp()
-        self.serv.listen(1)
+        self.serv.listen()
 
 
 class ThreadedSocketTestMixin(ThreadSafeCleanupTestCase, SocketTestBase,
@@ -716,11 +718,11 @@ class GeneralModuleTests(unittest.TestCase):
         with self.assertRaises(TypeError) as cm:
             s.sendto('\u2620', sockname)
         self.assertEqual(str(cm.exception),
-                         "'str' does not support the buffer interface")
+                         "a bytes-like object is required, not 'str'")
         with self.assertRaises(TypeError) as cm:
             s.sendto(5j, sockname)
         self.assertEqual(str(cm.exception),
-                         "'complex' does not support the buffer interface")
+                         "a bytes-like object is required, not 'complex'")
         with self.assertRaises(TypeError) as cm:
             s.sendto(b'foo', None)
         self.assertIn('not NoneType',str(cm.exception))
@@ -728,11 +730,11 @@ class GeneralModuleTests(unittest.TestCase):
         with self.assertRaises(TypeError) as cm:
             s.sendto('\u2620', 0, sockname)
         self.assertEqual(str(cm.exception),
-                         "'str' does not support the buffer interface")
+                         "a bytes-like object is required, not 'str'")
         with self.assertRaises(TypeError) as cm:
             s.sendto(5j, 0, sockname)
         self.assertEqual(str(cm.exception),
-                         "'complex' does not support the buffer interface")
+                         "a bytes-like object is required, not 'complex'")
         with self.assertRaises(TypeError) as cm:
             s.sendto(b'foo', 0, None)
         self.assertIn('not NoneType', str(cm.exception))
@@ -1378,10 +1380,13 @@ class GeneralModuleTests(unittest.TestCase):
 
     def test_listen_backlog(self):
         for backlog in 0, -1:
-            srv = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+            with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as srv:
+                srv.bind((HOST, 0))
+                srv.listen(backlog)
+
+        with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as srv:
             srv.bind((HOST, 0))
-            srv.listen(backlog)
-            srv.close()
+            srv.listen()
 
     @support.cpython_only
     def test_listen_backlog_overflow(self):
@@ -3585,7 +3590,7 @@ class InterruptedTimeoutBase(unittest.TestCase):
     def setUp(self):
         super().setUp()
         orig_alrm_handler = signal.signal(signal.SIGALRM,
-                                          lambda signum, frame: None)
+                                          lambda signum, frame: 1 / 0)
         self.addCleanup(signal.signal, signal.SIGALRM, orig_alrm_handler)
         self.addCleanup(self.setAlarm, 0)
 
@@ -3622,13 +3627,11 @@ class InterruptedRecvTimeoutTest(InterruptedTimeoutBase, UDPTestBase):
         self.serv.settimeout(self.timeout)
 
     def checkInterruptedRecv(self, func, *args, **kwargs):
-        # Check that func(*args, **kwargs) raises OSError with an
+        # Check that func(*args, **kwargs) raises
         # errno of EINTR when interrupted by a signal.
         self.setAlarm(self.alarm_time)
-        with self.assertRaises(OSError) as cm:
+        with self.assertRaises(ZeroDivisionError) as cm:
             func(*args, **kwargs)
-        self.assertNotIsInstance(cm.exception, socket.timeout)
-        self.assertEqual(cm.exception.errno, errno.EINTR)
 
     def testInterruptedRecvTimeout(self):
         self.checkInterruptedRecv(self.serv.recv, 1024)
@@ -3684,12 +3687,10 @@ class InterruptedSendTimeoutTest(InterruptedTimeoutBase,
         # Check that func(*args, **kwargs), run in a loop, raises
         # OSError with an errno of EINTR when interrupted by a
         # signal.
-        with self.assertRaises(OSError) as cm:
+        with self.assertRaises(ZeroDivisionError) as cm:
             while True:
                 self.setAlarm(self.alarm_time)
                 func(*args, **kwargs)
-        self.assertNotIsInstance(cm.exception, socket.timeout)
-        self.assertEqual(cm.exception.errno, errno.EINTR)
 
     # Issue #12958: The following tests have problems on OS X prior to 10.7
     @support.requires_mac_ver(10, 7)
@@ -3731,8 +3732,6 @@ class TCPCloserTest(ThreadedTCPSocketTest):
         self.cli.connect((HOST, self.port))
         time.sleep(1.0)
 
-@unittest.skipUnless(hasattr(socket, 'socketpair'),
-                     'test needs socket.socketpair()')
 @unittest.skipUnless(thread, 'Threading required for this test.')
 class BasicSocketPairTest(SocketPairTest):
 
@@ -3813,7 +3812,7 @@ class NonBlockingTCPTests(ThreadedTCPSocketTest):
         self.serv = socket.socket(socket.AF_INET, socket.SOCK_STREAM |
                                                   socket.SOCK_NONBLOCK)
         self.port = support.bind_port(self.serv)
-        self.serv.listen(1)
+        self.serv.listen()
         # actual testing
         start = time.time()
         try:
@@ -4059,117 +4058,6 @@ class FileObjectClassTestCase(SocketConnectedTest):
         pass
 
 
-class FileObjectInterruptedTestCase(unittest.TestCase):
-    """Test that the file object correctly handles EINTR internally."""
-
-    class MockSocket(object):
-        def __init__(self, recv_funcs=()):
-            # A generator that returns callables that we'll call for each
-            # call to recv().
-            self._recv_step = iter(recv_funcs)
-
-        def recv_into(self, buffer):
-            data = next(self._recv_step)()
-            assert len(buffer) >= len(data)
-            buffer[:len(data)] = data
-            return len(data)
-
-        def _decref_socketios(self):
-            pass
-
-        def _textiowrap_for_test(self, buffering=-1):
-            raw = socket.SocketIO(self, "r")
-            if buffering < 0:
-                buffering = io.DEFAULT_BUFFER_SIZE
-            if buffering == 0:
-                return raw
-            buffer = io.BufferedReader(raw, buffering)
-            text = io.TextIOWrapper(buffer, None, None)
-            text.mode = "rb"
-            return text
-
-    @staticmethod
-    def _raise_eintr():
-        raise OSError(errno.EINTR, "interrupted")
-
-    def _textiowrap_mock_socket(self, mock, buffering=-1):
-        raw = socket.SocketIO(mock, "r")
-        if buffering < 0:
-            buffering = io.DEFAULT_BUFFER_SIZE
-        if buffering == 0:
-            return raw
-        buffer = io.BufferedReader(raw, buffering)
-        text = io.TextIOWrapper(buffer, None, None)
-        text.mode = "rb"
-        return text
-
-    def _test_readline(self, size=-1, buffering=-1):
-        mock_sock = self.MockSocket(recv_funcs=[
-                lambda : b"This is the first line\nAnd the sec",
-                self._raise_eintr,
-                lambda : b"ond line is here\n",
-                lambda : b"",
-                lambda : b"",  # XXX(gps): io library does an extra EOF read
-            ])
-        fo = mock_sock._textiowrap_for_test(buffering=buffering)
-        self.assertEqual(fo.readline(size), "This is the first line\n")
-        self.assertEqual(fo.readline(size), "And the second line is here\n")
-
-    def _test_read(self, size=-1, buffering=-1):
-        mock_sock = self.MockSocket(recv_funcs=[
-                lambda : b"This is the first line\nAnd the sec",
-                self._raise_eintr,
-                lambda : b"ond line is here\n",
-                lambda : b"",
-                lambda : b"",  # XXX(gps): io library does an extra EOF read
-            ])
-        expecting = (b"This is the first line\n"
-                     b"And the second line is here\n")
-        fo = mock_sock._textiowrap_for_test(buffering=buffering)
-        if buffering == 0:
-            data = b''
-        else:
-            data = ''
-            expecting = expecting.decode('utf-8')
-        while len(data) != len(expecting):
-            part = fo.read(size)
-            if not part:
-                break
-            data += part
-        self.assertEqual(data, expecting)
-
-    def test_default(self):
-        self._test_readline()
-        self._test_readline(size=100)
-        self._test_read()
-        self._test_read(size=100)
-
-    def test_with_1k_buffer(self):
-        self._test_readline(buffering=1024)
-        self._test_readline(size=100, buffering=1024)
-        self._test_read(buffering=1024)
-        self._test_read(size=100, buffering=1024)
-
-    def _test_readline_no_buffer(self, size=-1):
-        mock_sock = self.MockSocket(recv_funcs=[
-                lambda : b"a",
-                lambda : b"\n",
-                lambda : b"B",
-                self._raise_eintr,
-                lambda : b"b",
-                lambda : b"",
-            ])
-        fo = mock_sock._textiowrap_for_test(buffering=0)
-        self.assertEqual(fo.readline(size), b"a\n")
-        self.assertEqual(fo.readline(size), b"Bb")
-
-    def test_no_buffer(self):
-        self._test_readline_no_buffer()
-        self._test_readline_no_buffer(size=4)
-        self._test_read(buffering=0)
-        self._test_read(size=100, buffering=0)
-
-
 class UnbufferedFileObjectClassTestCase(FileObjectClassTestCase):
 
     """Repeat the tests from FileObjectClassTestCase with bufsize==0.
@@ -4588,7 +4476,7 @@ class TestLinuxAbstractNamespace(unittest.TestCase):
         address = b"\x00python-test-hello\x00\xff"
         with socket.socket(socket.AF_UNIX, socket.SOCK_STREAM) as s1:
             s1.bind(address)
-            s1.listen(1)
+            s1.listen()
             with socket.socket(socket.AF_UNIX, socket.SOCK_STREAM) as s2:
                 s2.connect(s1.getsockname())
                 with s1.accept()[0] as s3:
@@ -4820,7 +4708,7 @@ class TIPCThreadableTest(unittest.TestCase, ThreadableTest):
         srvaddr = (socket.TIPC_ADDR_NAMESEQ, TIPC_STYPE,
                 TIPC_LOWER, TIPC_UPPER)
         self.srv.bind(srvaddr)
-        self.srv.listen(5)
+        self.srv.listen()
         self.serverExplicitReady()
         self.conn, self.connaddr = self.srv.accept()
         self.addCleanup(self.conn.close)
@@ -5109,6 +4997,275 @@ class TestSocketSharing(SocketTCPTest):
                     source.close()
 
 
+@unittest.skipUnless(thread, 'Threading required for this test.')
+class SendfileUsingSendTest(ThreadedTCPSocketTest):
+    """
+    Test the send() implementation of socket.sendfile().
+    """
+
+    FILESIZE = (10 * 1024 * 1024)  # 10MB
+    BUFSIZE = 8192
+    FILEDATA = b""
+    TIMEOUT = 2
+
+    @classmethod
+    def setUpClass(cls):
+        def chunks(total, step):
+            assert total >= step
+            while total > step:
+                yield step
+                total -= step
+            if total:
+                yield total
+
+        chunk = b"".join([random.choice(string.ascii_letters).encode()
+                          for i in range(cls.BUFSIZE)])
+        with open(support.TESTFN, 'wb') as f:
+            for csize in chunks(cls.FILESIZE, cls.BUFSIZE):
+                f.write(chunk)
+        with open(support.TESTFN, 'rb') as f:
+            cls.FILEDATA = f.read()
+            assert len(cls.FILEDATA) == cls.FILESIZE
+
+    @classmethod
+    def tearDownClass(cls):
+        support.unlink(support.TESTFN)
+
+    def accept_conn(self):
+        self.serv.settimeout(self.TIMEOUT)
+        conn, addr = self.serv.accept()
+        conn.settimeout(self.TIMEOUT)
+        self.addCleanup(conn.close)
+        return conn
+
+    def recv_data(self, conn):
+        received = []
+        while True:
+            chunk = conn.recv(self.BUFSIZE)
+            if not chunk:
+                break
+            received.append(chunk)
+        return b''.join(received)
+
+    def meth_from_sock(self, sock):
+        # Depending on the mixin class being run return either send()
+        # or sendfile() method implementation.
+        return getattr(sock, "_sendfile_use_send")
+
+    # regular file
+
+    def _testRegularFile(self):
+        address = self.serv.getsockname()
+        file = open(support.TESTFN, 'rb')
+        with socket.create_connection(address) as sock, file as file:
+            meth = self.meth_from_sock(sock)
+            sent = meth(file)
+            self.assertEqual(sent, self.FILESIZE)
+            self.assertEqual(file.tell(), self.FILESIZE)
+
+    def testRegularFile(self):
+        conn = self.accept_conn()
+        data = self.recv_data(conn)
+        self.assertEqual(len(data), self.FILESIZE)
+        self.assertEqual(data, self.FILEDATA)
+
+    # non regular file
+
+    def _testNonRegularFile(self):
+        address = self.serv.getsockname()
+        file = io.BytesIO(self.FILEDATA)
+        with socket.create_connection(address) as sock, file as file:
+            sent = sock.sendfile(file)
+            self.assertEqual(sent, self.FILESIZE)
+            self.assertEqual(file.tell(), self.FILESIZE)
+            self.assertRaises(socket._GiveupOnSendfile,
+                              sock._sendfile_use_sendfile, file)
+
+    def testNonRegularFile(self):
+        conn = self.accept_conn()
+        data = self.recv_data(conn)
+        self.assertEqual(len(data), self.FILESIZE)
+        self.assertEqual(data, self.FILEDATA)
+
+    # empty file
+
+    def _testEmptyFileSend(self):
+        address = self.serv.getsockname()
+        filename = support.TESTFN + "2"
+        with open(filename, 'wb'):
+            self.addCleanup(support.unlink, filename)
+        file = open(filename, 'rb')
+        with socket.create_connection(address) as sock, file as file:
+            meth = self.meth_from_sock(sock)
+            sent = meth(file)
+            self.assertEqual(sent, 0)
+            self.assertEqual(file.tell(), 0)
+
+    def testEmptyFileSend(self):
+        conn = self.accept_conn()
+        data = self.recv_data(conn)
+        self.assertEqual(data, b"")
+
+    # offset
+
+    def _testOffset(self):
+        address = self.serv.getsockname()
+        file = open(support.TESTFN, 'rb')
+        with socket.create_connection(address) as sock, file as file:
+            meth = self.meth_from_sock(sock)
+            sent = meth(file, offset=5000)
+            self.assertEqual(sent, self.FILESIZE - 5000)
+            self.assertEqual(file.tell(), self.FILESIZE)
+
+    def testOffset(self):
+        conn = self.accept_conn()
+        data = self.recv_data(conn)
+        self.assertEqual(len(data), self.FILESIZE - 5000)
+        self.assertEqual(data, self.FILEDATA[5000:])
+
+    # count
+
+    def _testCount(self):
+        address = self.serv.getsockname()
+        file = open(support.TESTFN, 'rb')
+        with socket.create_connection(address, timeout=2) as sock, file as file:
+            count = 5000007
+            meth = self.meth_from_sock(sock)
+            sent = meth(file, count=count)
+            self.assertEqual(sent, count)
+            self.assertEqual(file.tell(), count)
+
+    def testCount(self):
+        count = 5000007
+        conn = self.accept_conn()
+        data = self.recv_data(conn)
+        self.assertEqual(len(data), count)
+        self.assertEqual(data, self.FILEDATA[:count])
+
+    # count small
+
+    def _testCountSmall(self):
+        address = self.serv.getsockname()
+        file = open(support.TESTFN, 'rb')
+        with socket.create_connection(address, timeout=2) as sock, file as file:
+            count = 1
+            meth = self.meth_from_sock(sock)
+            sent = meth(file, count=count)
+            self.assertEqual(sent, count)
+            self.assertEqual(file.tell(), count)
+
+    def testCountSmall(self):
+        count = 1
+        conn = self.accept_conn()
+        data = self.recv_data(conn)
+        self.assertEqual(len(data), count)
+        self.assertEqual(data, self.FILEDATA[:count])
+
+    # count + offset
+
+    def _testCountWithOffset(self):
+        address = self.serv.getsockname()
+        file = open(support.TESTFN, 'rb')
+        with socket.create_connection(address, timeout=2) as sock, file as file:
+            count = 100007
+            meth = self.meth_from_sock(sock)
+            sent = meth(file, offset=2007, count=count)
+            self.assertEqual(sent, count)
+            self.assertEqual(file.tell(), count + 2007)
+
+    def testCountWithOffset(self):
+        count = 100007
+        conn = self.accept_conn()
+        data = self.recv_data(conn)
+        self.assertEqual(len(data), count)
+        self.assertEqual(data, self.FILEDATA[2007:count+2007])
+
+    # non blocking sockets are not supposed to work
+
+    def _testNonBlocking(self):
+        address = self.serv.getsockname()
+        file = open(support.TESTFN, 'rb')
+        with socket.create_connection(address) as sock, file as file:
+            sock.setblocking(False)
+            meth = self.meth_from_sock(sock)
+            self.assertRaises(ValueError, meth, file)
+            self.assertRaises(ValueError, sock.sendfile, file)
+
+    def testNonBlocking(self):
+        conn = self.accept_conn()
+        if conn.recv(8192):
+            self.fail('was not supposed to receive any data')
+
+    # timeout (non-triggered)
+
+    def _testWithTimeout(self):
+        address = self.serv.getsockname()
+        file = open(support.TESTFN, 'rb')
+        with socket.create_connection(address, timeout=2) as sock, file as file:
+            meth = self.meth_from_sock(sock)
+            sent = meth(file)
+            self.assertEqual(sent, self.FILESIZE)
+
+    def testWithTimeout(self):
+        conn = self.accept_conn()
+        data = self.recv_data(conn)
+        self.assertEqual(len(data), self.FILESIZE)
+        self.assertEqual(data, self.FILEDATA)
+
+    # timeout (triggered)
+
+    def _testWithTimeoutTriggeredSend(self):
+        address = self.serv.getsockname()
+        file = open(support.TESTFN, 'rb')
+        with socket.create_connection(address, timeout=0.01) as sock, \
+                file as file:
+            meth = self.meth_from_sock(sock)
+            self.assertRaises(socket.timeout, meth, file)
+
+    def testWithTimeoutTriggeredSend(self):
+        conn = self.accept_conn()
+        conn.recv(88192)
+
+    # errors
+
+    def _test_errors(self):
+        pass
+
+    def test_errors(self):
+        with open(support.TESTFN, 'rb') as file:
+            with socket.socket(type=socket.SOCK_DGRAM) as s:
+                meth = self.meth_from_sock(s)
+                self.assertRaisesRegex(
+                    ValueError, "SOCK_STREAM", meth, file)
+        with open(support.TESTFN, 'rt') as file:
+            with socket.socket() as s:
+                meth = self.meth_from_sock(s)
+                self.assertRaisesRegex(
+                    ValueError, "binary mode", meth, file)
+        with open(support.TESTFN, 'rb') as file:
+            with socket.socket() as s:
+                meth = self.meth_from_sock(s)
+                self.assertRaisesRegex(TypeError, "positive integer",
+                                       meth, file, count='2')
+                self.assertRaisesRegex(TypeError, "positive integer",
+                                       meth, file, count=0.1)
+                self.assertRaisesRegex(ValueError, "positive integer",
+                                       meth, file, count=0)
+                self.assertRaisesRegex(ValueError, "positive integer",
+                                       meth, file, count=-1)
+
+
+@unittest.skipUnless(thread, 'Threading required for this test.')
+@unittest.skipUnless(hasattr(os, "sendfile"),
+                     'os.sendfile() required for this test.')
+class SendfileUsingSendfileTest(SendfileUsingSendTest):
+    """
+    Test the sendfile() implementation of socket.sendfile().
+    """
+    def meth_from_sock(self, sock):
+        return getattr(sock, "_sendfile_use_sendfile")
+
+
 def test_main():
     tests = [GeneralModuleTests, BasicTCPTest, TCPCloserTest, TCPTimeoutTest,
              TestExceptions, BufferIOTest, BasicTCPTest2, BasicUDPTest, UDPTimeoutTest ]
@@ -5116,7 +5273,6 @@ def test_main():
     tests.extend([
         NonBlockingTCPTests,
         FileObjectClassTestCase,
-        FileObjectInterruptedTestCase,
         UnbufferedFileObjectClassTestCase,
         LineBufferedFileObjectClassTestCase,
         SmallBufferedFileObjectClassTestCase,
@@ -5161,6 +5317,8 @@ def test_main():
         InterruptedRecvTimeoutTest,
         InterruptedSendTimeoutTest,
         TestSocketSharing,
+        SendfileUsingSendTest,
+        SendfileUsingSendfileTest,
     ])
 
     thread_info = support.threading_setup()
diff --git a/Lib/test/test_socketserver.py b/Lib/test/test_socketserver.py
index 924b9c4d22..31ab3b64f5 100644
--- a/Lib/test/test_socketserver.py
+++ b/Lib/test/test_socketserver.py
@@ -221,38 +221,6 @@ class SocketServerTest(unittest.TestCase):
                             socketserver.DatagramRequestHandler,
                             self.dgram_examine)
 
-    @contextlib.contextmanager
-    def mocked_select_module(self):
-        """Mocks the select.select() call to raise EINTR for first call"""
-        old_select = select.select
-
-        class MockSelect:
-            def __init__(self):
-                self.called = 0
-
-            def __call__(self, *args):
-                self.called += 1
-                if self.called == 1:
-                    # raise the exception on first call
-                    raise OSError(errno.EINTR, os.strerror(errno.EINTR))
-                else:
-                    # Return real select value for consecutive calls
-                    return old_select(*args)
-
-        select.select = MockSelect()
-        try:
-            yield select.select
-        finally:
-            select.select = old_select
-
-    def test_InterruptServerSelectCall(self):
-        with self.mocked_select_module() as mock_select:
-            pid = self.run_server(socketserver.TCPServer,
-                                  socketserver.StreamRequestHandler,
-                                  self.stream_examine)
-            # Make sure select was called again:
-            self.assertGreater(mock_select.called, 1)
-
     # Alas, on Linux (at least) recvfrom() doesn't return a meaningful
     # client address so this cannot work:
 
diff --git a/Lib/test/test_ssl.py b/Lib/test/test_ssl.py
index dc82475a9d..ce427b4db2 100644
--- a/Lib/test/test_ssl.py
+++ b/Lib/test/test_ssl.py
@@ -86,6 +86,12 @@ def have_verify_flags():
     # 0.9.8 or higher
     return ssl.OPENSSL_VERSION_INFO >= (0, 9, 8, 0, 15)
 
+def utc_offset(): #NOTE: ignore issues like #1647654
+    # local time = utc time + utc offset
+    if time.daylight and time.localtime().tm_isdst > 0:
+        return -time.altzone  # seconds
+    return -time.timezone
+
 def asn1time(cert_time):
     # Some versions of OpenSSL ignore seconds, see #18207
     # 0.9.8.i
@@ -134,6 +140,14 @@ class BasicSocketTests(unittest.TestCase):
         self.assertIn(ssl.HAS_SNI, {True, False})
         self.assertIn(ssl.HAS_ECDH, {True, False})
 
+    def test_str_for_enums(self):
+        # Make sure that the PROTOCOL_* constants have enum-like string
+        # reprs.
+        proto = ssl.PROTOCOL_SSLv23
+        self.assertEqual(str(proto), '_SSLMethod.PROTOCOL_SSLv23')
+        ctx = ssl.SSLContext(proto)
+        self.assertIs(ctx.protocol, proto)
+
     def test_random(self):
         v = ssl.RAND_status()
         if support.verbose:
@@ -298,10 +312,10 @@ class BasicSocketTests(unittest.TestCase):
         # Version string as returned by {Open,Libre}SSL, the format might change
         if "LibreSSL" in s:
             self.assertTrue(s.startswith("LibreSSL {:d}.{:d}".format(major, minor)),
-                            (s, t))
+                            (s, t, hex(n)))
         else:
             self.assertTrue(s.startswith("OpenSSL {:d}.{:d}.{:d}".format(major, minor, fix)),
-                            (s, t))
+                            (s, t, hex(n)))
 
     @support.cpython_only
     def test_refcycle(self):
@@ -369,6 +383,8 @@ class BasicSocketTests(unittest.TestCase):
             self.assertRaises(ssl.CertificateError,
                               ssl.match_hostname, cert, hostname)
 
+        # -- Hostname matching --
+
         cert = {'subject': ((('commonName', 'example.com'),),)}
         ok(cert, 'example.com')
         ok(cert, 'ExAmple.cOm')
@@ -454,6 +470,28 @@ class BasicSocketTests(unittest.TestCase):
         # Only commonName is considered
         fail(cert, 'California')
 
+        # -- IPv4 matching --
+        cert = {'subject': ((('commonName', 'example.com'),),),
+                'subjectAltName': (('DNS', 'example.com'),
+                                   ('IP Address', '10.11.12.13'),
+                                   ('IP Address', '14.15.16.17'))}
+        ok(cert, '10.11.12.13')
+        ok(cert, '14.15.16.17')
+        fail(cert, '14.15.16.18')
+        fail(cert, 'example.net')
+
+        # -- IPv6 matching --
+        cert = {'subject': ((('commonName', 'example.com'),),),
+                'subjectAltName': (('DNS', 'example.com'),
+                                   ('IP Address', '2001:0:0:0:0:0:0:CAFE\n'),
+                                   ('IP Address', '2003:0:0:0:0:0:0:BABA\n'))}
+        ok(cert, '2001::cafe')
+        ok(cert, '2003::baba')
+        fail(cert, '2003::bebe')
+        fail(cert, 'example.net')
+
+        # -- Miscellaneous --
+
         # Neither commonName nor subjectAltName
         cert = {'notAfter': 'Dec 18 23:59:59 2011 GMT',
                 'subject': ((('countryName', 'US'),),
@@ -505,9 +543,14 @@ class BasicSocketTests(unittest.TestCase):
     def test_unknown_channel_binding(self):
         # should raise ValueError for unknown type
         s = socket.socket(socket.AF_INET)
-        with ssl.wrap_socket(s) as ss:
+        s.bind(('127.0.0.1', 0))
+        s.listen()
+        c = socket.socket(socket.AF_INET)
+        c.connect(s.getsockname())
+        with ssl.wrap_socket(c, do_handshake_on_connect=False) as ss:
             with self.assertRaises(ValueError):
                 ss.get_channel_binding("unknown-type")
+        s.close()
 
     @unittest.skipUnless("tls-unique" in ssl.CHANNEL_BINDING_TYPES,
                          "'tls-unique' channel binding not available")
@@ -648,6 +691,71 @@ class BasicSocketTests(unittest.TestCase):
             ctx.wrap_socket(s)
         self.assertEqual(str(cx.exception), "only stream sockets are supported")
 
+    def cert_time_ok(self, timestring, timestamp):
+        self.assertEqual(ssl.cert_time_to_seconds(timestring), timestamp)
+
+    def cert_time_fail(self, timestring):
+        with self.assertRaises(ValueError):
+            ssl.cert_time_to_seconds(timestring)
+
+    @unittest.skipUnless(utc_offset(),
+                         'local time needs to be different from UTC')
+    def test_cert_time_to_seconds_timezone(self):
+        # Issue #19940: ssl.cert_time_to_seconds() returns wrong
+        #               results if local timezone is not UTC
+        self.cert_time_ok("May  9 00:00:00 2007 GMT", 1178668800.0)
+        self.cert_time_ok("Jan  5 09:34:43 2018 GMT", 1515144883.0)
+
+    def test_cert_time_to_seconds(self):
+        timestring = "Jan  5 09:34:43 2018 GMT"
+        ts = 1515144883.0
+        self.cert_time_ok(timestring, ts)
+        # accept keyword parameter, assert its name
+        self.assertEqual(ssl.cert_time_to_seconds(cert_time=timestring), ts)
+        # accept both %e and %d (space or zero generated by strftime)
+        self.cert_time_ok("Jan 05 09:34:43 2018 GMT", ts)
+        # case-insensitive
+        self.cert_time_ok("JaN  5 09:34:43 2018 GmT", ts)
+        self.cert_time_fail("Jan  5 09:34 2018 GMT")     # no seconds
+        self.cert_time_fail("Jan  5 09:34:43 2018")      # no GMT
+        self.cert_time_fail("Jan  5 09:34:43 2018 UTC")  # not GMT timezone
+        self.cert_time_fail("Jan 35 09:34:43 2018 GMT")  # invalid day
+        self.cert_time_fail("Jon  5 09:34:43 2018 GMT")  # invalid month
+        self.cert_time_fail("Jan  5 24:00:00 2018 GMT")  # invalid hour
+        self.cert_time_fail("Jan  5 09:60:43 2018 GMT")  # invalid minute
+
+        newyear_ts = 1230768000.0
+        # leap seconds
+        self.cert_time_ok("Dec 31 23:59:60 2008 GMT", newyear_ts)
+        # same timestamp
+        self.cert_time_ok("Jan  1 00:00:00 2009 GMT", newyear_ts)
+
+        self.cert_time_ok("Jan  5 09:34:59 2018 GMT", 1515144899)
+        #  allow 60th second (even if it is not a leap second)
+        self.cert_time_ok("Jan  5 09:34:60 2018 GMT", 1515144900)
+        #  allow 2nd leap second for compatibility with time.strptime()
+        self.cert_time_ok("Jan  5 09:34:61 2018 GMT", 1515144901)
+        self.cert_time_fail("Jan  5 09:34:62 2018 GMT")  # invalid seconds
+
+        # no special treatement for the special value:
+        #   99991231235959Z (rfc 5280)
+        self.cert_time_ok("Dec 31 23:59:59 9999 GMT", 253402300799.0)
+
+    @support.run_with_locale('LC_ALL', '')
+    def test_cert_time_to_seconds_locale(self):
+        # `cert_time_to_seconds()` should be locale independent
+
+        def local_february_name():
+            return time.strftime('%b', (1, 2, 3, 4, 5, 6, 0, 0, 0))
+
+        if local_february_name().lower() == 'feb':
+            self.skipTest("locale-specific month name needs to be "
+                          "different from C locale")
+
+        # locale-independent
+        self.cert_time_ok("Feb  9 00:00:00 2007 GMT", 1170979200.0)
+        self.cert_time_fail(local_february_name() + "  9 00:00:00 2007 GMT")
+
 
 class ContextTests(unittest.TestCase):
 
@@ -1156,7 +1264,7 @@ class SSLErrorTests(unittest.TestCase):
         ctx = ssl.SSLContext(ssl.PROTOCOL_TLSv1)
         with socket.socket() as s:
             s.bind(("127.0.0.1", 0))
-            s.listen(5)
+            s.listen()
             c = socket.socket()
             c.connect(s.getsockname())
             c.setblocking(False)
@@ -1169,6 +1277,69 @@ class SSLErrorTests(unittest.TestCase):
                 self.assertEqual(cm.exception.errno, ssl.SSL_ERROR_WANT_READ)
 
 
+class MemoryBIOTests(unittest.TestCase):
+
+    def test_read_write(self):
+        bio = ssl.MemoryBIO()
+        bio.write(b'foo')
+        self.assertEqual(bio.read(), b'foo')
+        self.assertEqual(bio.read(), b'')
+        bio.write(b'foo')
+        bio.write(b'bar')
+        self.assertEqual(bio.read(), b'foobar')
+        self.assertEqual(bio.read(), b'')
+        bio.write(b'baz')
+        self.assertEqual(bio.read(2), b'ba')
+        self.assertEqual(bio.read(1), b'z')
+        self.assertEqual(bio.read(1), b'')
+
+    def test_eof(self):
+        bio = ssl.MemoryBIO()
+        self.assertFalse(bio.eof)
+        self.assertEqual(bio.read(), b'')
+        self.assertFalse(bio.eof)
+        bio.write(b'foo')
+        self.assertFalse(bio.eof)
+        bio.write_eof()
+        self.assertFalse(bio.eof)
+        self.assertEqual(bio.read(2), b'fo')
+        self.assertFalse(bio.eof)
+        self.assertEqual(bio.read(1), b'o')
+        self.assertTrue(bio.eof)
+        self.assertEqual(bio.read(), b'')
+        self.assertTrue(bio.eof)
+
+    def test_pending(self):
+        bio = ssl.MemoryBIO()
+        self.assertEqual(bio.pending, 0)
+        bio.write(b'foo')
+        self.assertEqual(bio.pending, 3)
+        for i in range(3):
+            bio.read(1)
+            self.assertEqual(bio.pending, 3-i-1)
+        for i in range(3):
+            bio.write(b'x')
+            self.assertEqual(bio.pending, i+1)
+        bio.read()
+        self.assertEqual(bio.pending, 0)
+
+    def test_buffer_types(self):
+        bio = ssl.MemoryBIO()
+        bio.write(b'foo')
+        self.assertEqual(bio.read(), b'foo')
+        bio.write(bytearray(b'bar'))
+        self.assertEqual(bio.read(), b'bar')
+        bio.write(memoryview(b'baz'))
+        self.assertEqual(bio.read(), b'baz')
+
+    def test_error_types(self):
+        bio = ssl.MemoryBIO()
+        self.assertRaises(TypeError, bio.write, 'foo')
+        self.assertRaises(TypeError, bio.write, None)
+        self.assertRaises(TypeError, bio.write, True)
+        self.assertRaises(TypeError, bio.write, 1)
+
+
 class NetworkedTests(unittest.TestCase):
 
     def test_connect(self):
@@ -1396,14 +1567,12 @@ class NetworkedTests(unittest.TestCase):
     def test_get_server_certificate(self):
         def _test_get_server_certificate(host, port, cert=None):
             with support.transient_internet(host):
-                pem = ssl.get_server_certificate((host, port),
-                                                 ssl.PROTOCOL_SSLv23)
+                pem = ssl.get_server_certificate((host, port))
                 if not pem:
                     self.fail("No server certificate on %s:%s!" % (host, port))
 
                 try:
                     pem = ssl.get_server_certificate((host, port),
-                                                     ssl.PROTOCOL_SSLv23,
                                                      ca_certs=CERTFILE)
                 except ssl.SSLError as x:
                     #should fail
@@ -1413,7 +1582,6 @@ class NetworkedTests(unittest.TestCase):
                     self.fail("Got server certificate %s for %s:%s!" % (pem, host, port))
 
                 pem = ssl.get_server_certificate((host, port),
-                                                 ssl.PROTOCOL_SSLv23,
                                                  ca_certs=cert)
                 if not pem:
                     self.fail("No server certificate on %s:%s!" % (host, port))
@@ -1499,6 +1667,93 @@ class NetworkedTests(unittest.TestCase):
                 self.assertIs(ss.context, ctx2)
                 self.assertIs(ss._sslobj.context, ctx2)
 
+
+class NetworkedBIOTests(unittest.TestCase):
+
+    def ssl_io_loop(self, sock, incoming, outgoing, func, *args, **kwargs):
+        # A simple IO loop. Call func(*args) depending on the error we get
+        # (WANT_READ or WANT_WRITE) move data between the socket and the BIOs.
+        timeout = kwargs.get('timeout', 10)
+        count = 0
+        while True:
+            errno = None
+            count += 1
+            try:
+                ret = func(*args)
+            except ssl.SSLError as e:
+                # Note that we get a spurious -1/SSL_ERROR_SYSCALL for
+                # non-blocking IO. The SSL_shutdown manpage hints at this.
+                # It *should* be safe to just ignore SYS_ERROR_SYSCALL because
+                # with a Memory BIO there's no syscalls (for IO at least).
+                if e.errno not in (ssl.SSL_ERROR_WANT_READ,
+                                   ssl.SSL_ERROR_WANT_WRITE,
+                                   ssl.SSL_ERROR_SYSCALL):
+                    raise
+                errno = e.errno
+            # Get any data from the outgoing BIO irrespective of any error, and
+            # send it to the socket.
+            buf = outgoing.read()
+            sock.sendall(buf)
+            # If there's no error, we're done. For WANT_READ, we need to get
+            # data from the socket and put it in the incoming BIO.
+            if errno is None:
+                break
+            elif errno == ssl.SSL_ERROR_WANT_READ:
+                buf = sock.recv(32768)
+                if buf:
+                    incoming.write(buf)
+                else:
+                    incoming.write_eof()
+        if support.verbose:
+            sys.stdout.write("Needed %d calls to complete %s().\n"
+                             % (count, func.__name__))
+        return ret
+
+    def test_handshake(self):
+        with support.transient_internet("svn.python.org"):
+            sock = socket.socket(socket.AF_INET)
+            sock.connect(("svn.python.org", 443))
+            incoming = ssl.MemoryBIO()
+            outgoing = ssl.MemoryBIO()
+            ctx = ssl.SSLContext(ssl.PROTOCOL_SSLv23)
+            ctx.verify_mode = ssl.CERT_REQUIRED
+            ctx.load_verify_locations(SVN_PYTHON_ORG_ROOT_CERT)
+            ctx.check_hostname = True
+            sslobj = ctx.wrap_bio(incoming, outgoing, False, 'svn.python.org')
+            self.assertIs(sslobj._sslobj.owner, sslobj)
+            self.assertIsNone(sslobj.cipher())
+            self.assertIsNone(sslobj.shared_ciphers())
+            self.assertRaises(ValueError, sslobj.getpeercert)
+            if 'tls-unique' in ssl.CHANNEL_BINDING_TYPES:
+                self.assertIsNone(sslobj.get_channel_binding('tls-unique'))
+            self.ssl_io_loop(sock, incoming, outgoing, sslobj.do_handshake)
+            self.assertTrue(sslobj.cipher())
+            self.assertIsNone(sslobj.shared_ciphers())
+            self.assertTrue(sslobj.getpeercert())
+            if 'tls-unique' in ssl.CHANNEL_BINDING_TYPES:
+                self.assertTrue(sslobj.get_channel_binding('tls-unique'))
+            self.ssl_io_loop(sock, incoming, outgoing, sslobj.unwrap)
+            self.assertRaises(ssl.SSLError, sslobj.write, b'foo')
+            sock.close()
+
+    def test_read_write_data(self):
+        with support.transient_internet("svn.python.org"):
+            sock = socket.socket(socket.AF_INET)
+            sock.connect(("svn.python.org", 443))
+            incoming = ssl.MemoryBIO()
+            outgoing = ssl.MemoryBIO()
+            ctx = ssl.SSLContext(ssl.PROTOCOL_SSLv23)
+            ctx.verify_mode = ssl.CERT_NONE
+            sslobj = ctx.wrap_bio(incoming, outgoing, False)
+            self.ssl_io_loop(sock, incoming, outgoing, sslobj.do_handshake)
+            req = b'GET / HTTP/1.0\r\n\r\n'
+            self.ssl_io_loop(sock, incoming, outgoing, sslobj.write, req)
+            buf = self.ssl_io_loop(sock, incoming, outgoing, sslobj.read, 1024)
+            self.assertEqual(buf[:5], b'HTTP/')
+            self.ssl_io_loop(sock, incoming, outgoing, sslobj.unwrap)
+            sock.close()
+
+
 try:
     import threading
 except ImportError:
@@ -1530,7 +1785,8 @@ else:
                 try:
                     self.sslconn = self.server.context.wrap_socket(
                         self.sock, server_side=True)
-                    self.server.selected_protocols.append(self.sslconn.selected_npn_protocol())
+                    self.server.selected_npn_protocols.append(self.sslconn.selected_npn_protocol())
+                    self.server.selected_alpn_protocols.append(self.sslconn.selected_alpn_protocol())
                 except (ssl.SSLError, ConnectionResetError) as e:
                     # We treat ConnectionResetError as though it were an
                     # SSLError - OpenSSL on Ubuntu abruptly closes the
@@ -1547,6 +1803,7 @@ else:
                     self.close()
                     return False
                 else:
+                    self.server.shared_ciphers.append(self.sslconn.shared_ciphers())
                     if self.server.context.verify_mode == ssl.CERT_REQUIRED:
                         cert = self.sslconn.getpeercert()
                         if support.verbose and self.server.chatty:
@@ -1637,7 +1894,8 @@ else:
         def __init__(self, certificate=None, ssl_version=None,
                      certreqs=None, cacerts=None,
                      chatty=True, connectionchatty=False, starttls_server=False,
-                     npn_protocols=None, ciphers=None, context=None):
+                     npn_protocols=None, alpn_protocols=None,
+                     ciphers=None, context=None):
             if context:
                 self.context = context
             else:
@@ -1652,6 +1910,8 @@ else:
                     self.context.load_cert_chain(certificate)
                 if npn_protocols:
                     self.context.set_npn_protocols(npn_protocols)
+                if alpn_protocols:
+                    self.context.set_alpn_protocols(alpn_protocols)
                 if ciphers:
                     self.context.set_ciphers(ciphers)
             self.chatty = chatty
@@ -1661,7 +1921,9 @@ else:
             self.port = support.bind_port(self.sock)
             self.flag = None
             self.active = False
-            self.selected_protocols = []
+            self.selected_npn_protocols = []
+            self.selected_alpn_protocols = []
+            self.shared_ciphers = []
             self.conn_errors = []
             threading.Thread.__init__(self)
             self.daemon = True
@@ -1681,7 +1943,7 @@ else:
 
         def run(self):
             self.sock.settimeout(0.05)
-            self.sock.listen(5)
+            self.sock.listen()
             self.active = True
             if self.flag:
                 # signal an event
@@ -1887,14 +2149,25 @@ else:
                     'compression': s.compression(),
                     'cipher': s.cipher(),
                     'peercert': s.getpeercert(),
-                    'client_npn_protocol': s.selected_npn_protocol()
+                    'client_alpn_protocol': s.selected_alpn_protocol(),
+                    'client_npn_protocol': s.selected_npn_protocol(),
+                    'version': s.version(),
                 })
                 s.close()
-            stats['server_npn_protocols'] = server.selected_protocols
+            stats['server_alpn_protocols'] = server.selected_alpn_protocols
+            stats['server_npn_protocols'] = server.selected_npn_protocols
+            stats['server_shared_ciphers'] = server.shared_ciphers
         return stats
 
     def try_protocol_combo(server_protocol, client_protocol, expect_success,
                            certsreqs=None, server_options=0, client_options=0):
+        """
+        Try to SSL-connect using *client_protocol* to *server_protocol*.
+        If *expect_success* is true, assert that the connection succeeds,
+        if it's false, assert that the connection fails.
+        Also, if *expect_success* is a string, assert that it is the protocol
+        version actually used by the connection.
+        """
         if certsreqs is None:
             certsreqs = ssl.CERT_NONE
         certtype = {
@@ -1924,8 +2197,8 @@ else:
             ctx.load_cert_chain(CERTFILE)
             ctx.load_verify_locations(CERTFILE)
         try:
-            server_params_test(client_context, server_context,
-                               chatty=False, connectionchatty=False)
+            stats = server_params_test(client_context, server_context,
+                                       chatty=False, connectionchatty=False)
         # Protocol mismatch can result in either an SSLError, or a
         # "Connection reset by peer" error.
         except ssl.SSLError:
@@ -1940,6 +2213,10 @@ else:
                     "Client protocol %s succeeded with server protocol %s!"
                     % (ssl.get_protocol_name(client_protocol),
                        ssl.get_protocol_name(server_protocol)))
+            elif (expect_success is not True
+                  and expect_success != stats['version']):
+                raise AssertionError("version mismatch: expected %r, got %r"
+                                     % (expect_success, stats['version']))
 
 
     class ThreadedTests(unittest.TestCase):
@@ -2106,7 +2383,7 @@ else:
             # and sets Event `listener_gone` to let the main thread know
             # the socket is gone.
             def listener():
-                s.listen(5)
+                s.listen()
                 listener_ready.set()
                 newsock, addr = s.accept()
                 newsock.close()
@@ -2171,19 +2448,19 @@ else:
                             " SSL2 client to SSL23 server test unexpectedly failed:\n %s\n"
                             % str(x))
             if hasattr(ssl, 'PROTOCOL_SSLv3'):
-                try_protocol_combo(ssl.PROTOCOL_SSLv23, ssl.PROTOCOL_SSLv3, True)
+                try_protocol_combo(ssl.PROTOCOL_SSLv23, ssl.PROTOCOL_SSLv3, 'SSLv3')
             try_protocol_combo(ssl.PROTOCOL_SSLv23, ssl.PROTOCOL_SSLv23, True)
-            try_protocol_combo(ssl.PROTOCOL_SSLv23, ssl.PROTOCOL_TLSv1, True)
+            try_protocol_combo(ssl.PROTOCOL_SSLv23, ssl.PROTOCOL_TLSv1, 'TLSv1')
 
             if hasattr(ssl, 'PROTOCOL_SSLv3'):
-                try_protocol_combo(ssl.PROTOCOL_SSLv23, ssl.PROTOCOL_SSLv3, True, ssl.CERT_OPTIONAL)
+                try_protocol_combo(ssl.PROTOCOL_SSLv23, ssl.PROTOCOL_SSLv3, 'SSLv3', ssl.CERT_OPTIONAL)
             try_protocol_combo(ssl.PROTOCOL_SSLv23, ssl.PROTOCOL_SSLv23, True, ssl.CERT_OPTIONAL)
-            try_protocol_combo(ssl.PROTOCOL_SSLv23, ssl.PROTOCOL_TLSv1, True, ssl.CERT_OPTIONAL)
+            try_protocol_combo(ssl.PROTOCOL_SSLv23, ssl.PROTOCOL_TLSv1, 'TLSv1', ssl.CERT_OPTIONAL)
 
             if hasattr(ssl, 'PROTOCOL_SSLv3'):
-                try_protocol_combo(ssl.PROTOCOL_SSLv23, ssl.PROTOCOL_SSLv3, True, ssl.CERT_REQUIRED)
+                try_protocol_combo(ssl.PROTOCOL_SSLv23, ssl.PROTOCOL_SSLv3, 'SSLv3', ssl.CERT_REQUIRED)
             try_protocol_combo(ssl.PROTOCOL_SSLv23, ssl.PROTOCOL_SSLv23, True, ssl.CERT_REQUIRED)
-            try_protocol_combo(ssl.PROTOCOL_SSLv23, ssl.PROTOCOL_TLSv1, True, ssl.CERT_REQUIRED)
+            try_protocol_combo(ssl.PROTOCOL_SSLv23, ssl.PROTOCOL_TLSv1, 'TLSv1', ssl.CERT_REQUIRED)
 
             # Server with specific SSL options
             if hasattr(ssl, 'PROTOCOL_SSLv3'):
@@ -2203,9 +2480,9 @@ else:
             """Connecting to an SSLv3 server with various client options"""
             if support.verbose:
                 sys.stdout.write("\n")
-            try_protocol_combo(ssl.PROTOCOL_SSLv3, ssl.PROTOCOL_SSLv3, True)
-            try_protocol_combo(ssl.PROTOCOL_SSLv3, ssl.PROTOCOL_SSLv3, True, ssl.CERT_OPTIONAL)
-            try_protocol_combo(ssl.PROTOCOL_SSLv3, ssl.PROTOCOL_SSLv3, True, ssl.CERT_REQUIRED)
+            try_protocol_combo(ssl.PROTOCOL_SSLv3, ssl.PROTOCOL_SSLv3, 'SSLv3')
+            try_protocol_combo(ssl.PROTOCOL_SSLv3, ssl.PROTOCOL_SSLv3, 'SSLv3', ssl.CERT_OPTIONAL)
+            try_protocol_combo(ssl.PROTOCOL_SSLv3, ssl.PROTOCOL_SSLv3, 'SSLv3', ssl.CERT_REQUIRED)
             if hasattr(ssl, 'PROTOCOL_SSLv2'):
                 try_protocol_combo(ssl.PROTOCOL_SSLv3, ssl.PROTOCOL_SSLv2, False)
             try_protocol_combo(ssl.PROTOCOL_SSLv3, ssl.PROTOCOL_SSLv23, False,
@@ -2213,7 +2490,7 @@ else:
             try_protocol_combo(ssl.PROTOCOL_SSLv3, ssl.PROTOCOL_TLSv1, False)
             if no_sslv2_implies_sslv3_hello():
                 # No SSLv2 => client will use an SSLv3 hello on recent OpenSSLs
-                try_protocol_combo(ssl.PROTOCOL_SSLv3, ssl.PROTOCOL_SSLv23, True,
+                try_protocol_combo(ssl.PROTOCOL_SSLv3, ssl.PROTOCOL_SSLv23, 'SSLv3',
                                    client_options=ssl.OP_NO_SSLv2)
 
         @skip_if_broken_ubuntu_ssl
@@ -2221,9 +2498,9 @@ else:
             """Connecting to a TLSv1 server with various client options"""
             if support.verbose:
                 sys.stdout.write("\n")
-            try_protocol_combo(ssl.PROTOCOL_TLSv1, ssl.PROTOCOL_TLSv1, True)
-            try_protocol_combo(ssl.PROTOCOL_TLSv1, ssl.PROTOCOL_TLSv1, True, ssl.CERT_OPTIONAL)
-            try_protocol_combo(ssl.PROTOCOL_TLSv1, ssl.PROTOCOL_TLSv1, True, ssl.CERT_REQUIRED)
+            try_protocol_combo(ssl.PROTOCOL_TLSv1, ssl.PROTOCOL_TLSv1, 'TLSv1')
+            try_protocol_combo(ssl.PROTOCOL_TLSv1, ssl.PROTOCOL_TLSv1, 'TLSv1', ssl.CERT_OPTIONAL)
+            try_protocol_combo(ssl.PROTOCOL_TLSv1, ssl.PROTOCOL_TLSv1, 'TLSv1', ssl.CERT_REQUIRED)
             if hasattr(ssl, 'PROTOCOL_SSLv2'):
                 try_protocol_combo(ssl.PROTOCOL_TLSv1, ssl.PROTOCOL_SSLv2, False)
             if hasattr(ssl, 'PROTOCOL_SSLv3'):
@@ -2239,7 +2516,7 @@ else:
                Testing against older TLS versions."""
             if support.verbose:
                 sys.stdout.write("\n")
-            try_protocol_combo(ssl.PROTOCOL_TLSv1_1, ssl.PROTOCOL_TLSv1_1, True)
+            try_protocol_combo(ssl.PROTOCOL_TLSv1_1, ssl.PROTOCOL_TLSv1_1, 'TLSv1.1')
             if hasattr(ssl, 'PROTOCOL_SSLv2'):
                 try_protocol_combo(ssl.PROTOCOL_TLSv1_1, ssl.PROTOCOL_SSLv2, False)
             if hasattr(ssl, 'PROTOCOL_SSLv3'):
@@ -2247,7 +2524,7 @@ else:
             try_protocol_combo(ssl.PROTOCOL_TLSv1_1, ssl.PROTOCOL_SSLv23, False,
                                client_options=ssl.OP_NO_TLSv1_1)
 
-            try_protocol_combo(ssl.PROTOCOL_SSLv23, ssl.PROTOCOL_TLSv1_1, True)
+            try_protocol_combo(ssl.PROTOCOL_SSLv23, ssl.PROTOCOL_TLSv1_1, 'TLSv1.1')
             try_protocol_combo(ssl.PROTOCOL_TLSv1_1, ssl.PROTOCOL_TLSv1, False)
             try_protocol_combo(ssl.PROTOCOL_TLSv1, ssl.PROTOCOL_TLSv1_1, False)
 
@@ -2260,7 +2537,7 @@ else:
                Testing against older TLS versions."""
             if support.verbose:
                 sys.stdout.write("\n")
-            try_protocol_combo(ssl.PROTOCOL_TLSv1_2, ssl.PROTOCOL_TLSv1_2, True,
+            try_protocol_combo(ssl.PROTOCOL_TLSv1_2, ssl.PROTOCOL_TLSv1_2, 'TLSv1.2',
                                server_options=ssl.OP_NO_SSLv3|ssl.OP_NO_SSLv2,
                                client_options=ssl.OP_NO_SSLv3|ssl.OP_NO_SSLv2,)
             if hasattr(ssl, 'PROTOCOL_SSLv2'):
@@ -2270,7 +2547,7 @@ else:
             try_protocol_combo(ssl.PROTOCOL_TLSv1_2, ssl.PROTOCOL_SSLv23, False,
                                client_options=ssl.OP_NO_TLSv1_2)
 
-            try_protocol_combo(ssl.PROTOCOL_SSLv23, ssl.PROTOCOL_TLSv1_2, True)
+            try_protocol_combo(ssl.PROTOCOL_SSLv23, ssl.PROTOCOL_TLSv1_2, 'TLSv1.2')
             try_protocol_combo(ssl.PROTOCOL_TLSv1_2, ssl.PROTOCOL_TLSv1, False)
             try_protocol_combo(ssl.PROTOCOL_TLSv1, ssl.PROTOCOL_TLSv1_2, False)
             try_protocol_combo(ssl.PROTOCOL_TLSv1_2, ssl.PROTOCOL_TLSv1_1, False)
@@ -2506,6 +2783,36 @@ else:
                 s.write(b"over\n")
                 s.close()
 
+        def test_nonblocking_send(self):
+            server = ThreadedEchoServer(CERTFILE,
+                                        certreqs=ssl.CERT_NONE,
+                                        ssl_version=ssl.PROTOCOL_TLSv1,
+                                        cacerts=CERTFILE,
+                                        chatty=True,
+                                        connectionchatty=False)
+            with server:
+                s = ssl.wrap_socket(socket.socket(),
+                                    server_side=False,
+                                    certfile=CERTFILE,
+                                    ca_certs=CERTFILE,
+                                    cert_reqs=ssl.CERT_NONE,
+                                    ssl_version=ssl.PROTOCOL_TLSv1)
+                s.connect((HOST, server.port))
+                s.setblocking(False)
+
+                # If we keep sending data, at some point the buffers
+                # will be full and the call will block
+                buf = bytearray(8192)
+                def fill_buffer():
+                    while True:
+                        s.send(buf)
+                self.assertRaises((ssl.SSLWantWriteError,
+                                   ssl.SSLWantReadError), fill_buffer)
+
+                # Now read all the output and discard it
+                s.setblocking(True)
+                s.close()
+
         def test_handshake_timeout(self):
             # Issue #5103: SSL handshake must respect the socket timeout
             server = socket.socket(socket.AF_INET)
@@ -2515,7 +2822,7 @@ else:
             finish = False
 
             def serve():
-                server.listen(5)
+                server.listen()
                 started.set()
                 conns = []
                 while not finish:
@@ -2572,7 +2879,7 @@ else:
             peer = None
             def serve():
                 nonlocal remote, peer
-                server.listen(5)
+                server.listen()
                 # Block on the accept and wait on the connection to close.
                 evt.set()
                 remote, peer = server.accept()
@@ -2622,6 +2929,21 @@ else:
                         s.connect((HOST, server.port))
             self.assertIn("no shared cipher", str(server.conn_errors[0]))
 
+        def test_version_basic(self):
+            """
+            Basic tests for SSLSocket.version().
+            More tests are done in the test_protocol_*() methods.
+            """
+            context = ssl.SSLContext(ssl.PROTOCOL_TLSv1)
+            with ThreadedEchoServer(CERTFILE,
+                                    ssl_version=ssl.PROTOCOL_TLSv1,
+                                    chatty=False) as server:
+                with context.wrap_socket(socket.socket()) as s:
+                    self.assertIs(s.version(), None)
+                    s.connect((HOST, server.port))
+                    self.assertEqual(s.version(), "TLSv1")
+                self.assertIs(s.version(), None)
+
         @unittest.skipUnless(ssl.HAS_ECDH, "test requires ECDH-enabled OpenSSL")
         def test_default_ecdh_curve(self):
             # Issue #21015: elliptic curve-based Diffie Hellman key exchange
@@ -2731,6 +3053,55 @@ else:
             if "ADH" not in parts and "EDH" not in parts and "DHE" not in parts:
                 self.fail("Non-DH cipher: " + cipher[0])
 
+        def test_selected_alpn_protocol(self):
+            # selected_alpn_protocol() is None unless ALPN is used.
+            context = ssl.SSLContext(ssl.PROTOCOL_TLSv1)
+            context.load_cert_chain(CERTFILE)
+            stats = server_params_test(context, context,
+                                       chatty=True, connectionchatty=True)
+            self.assertIs(stats['client_alpn_protocol'], None)
+
+        @unittest.skipUnless(ssl.HAS_ALPN, "ALPN support required")
+        def test_selected_alpn_protocol_if_server_uses_alpn(self):
+            # selected_alpn_protocol() is None unless ALPN is used by the client.
+            client_context = ssl.SSLContext(ssl.PROTOCOL_TLSv1)
+            client_context.load_verify_locations(CERTFILE)
+            server_context = ssl.SSLContext(ssl.PROTOCOL_TLSv1)
+            server_context.load_cert_chain(CERTFILE)
+            server_context.set_alpn_protocols(['foo', 'bar'])
+            stats = server_params_test(client_context, server_context,
+                                       chatty=True, connectionchatty=True)
+            self.assertIs(stats['client_alpn_protocol'], None)
+
+        @unittest.skipUnless(ssl.HAS_ALPN, "ALPN support needed for this test")
+        def test_alpn_protocols(self):
+            server_protocols = ['foo', 'bar', 'milkshake']
+            protocol_tests = [
+                (['foo', 'bar'], 'foo'),
+                (['bar', 'foo'], 'foo'),
+                (['milkshake'], 'milkshake'),
+                (['http/3.0', 'http/4.0'], None)
+            ]
+            for client_protocols, expected in protocol_tests:
+                server_context = ssl.SSLContext(ssl.PROTOCOL_TLSv1)
+                server_context.load_cert_chain(CERTFILE)
+                server_context.set_alpn_protocols(server_protocols)
+                client_context = ssl.SSLContext(ssl.PROTOCOL_TLSv1)
+                client_context.load_cert_chain(CERTFILE)
+                client_context.set_alpn_protocols(client_protocols)
+                stats = server_params_test(client_context, server_context,
+                                           chatty=True, connectionchatty=True)
+
+                msg = "failed trying %s (s) and %s (c).\n" \
+                      "was expecting %s, but got %%s from the %%s" \
+                          % (str(server_protocols), str(client_protocols),
+                             str(expected))
+                client_result = stats['client_alpn_protocol']
+                self.assertEqual(client_result, expected, msg % (client_result, "client"))
+                server_result = stats['server_alpn_protocols'][-1] \
+                    if len(stats['server_alpn_protocols']) else 'nothing'
+                self.assertEqual(server_result, expected, msg % (server_result, "server"))
+
         def test_selected_npn_protocol(self):
             # selected_npn_protocol() is None unless NPN is used
             context = ssl.SSLContext(ssl.PROTOCOL_TLSv1)
@@ -2871,6 +3242,20 @@ else:
             self.assertEqual(cm.exception.reason, 'TLSV1_ALERT_INTERNAL_ERROR')
             self.assertIn("TypeError", stderr.getvalue())
 
+        def test_shared_ciphers(self):
+            server_context = ssl.SSLContext(ssl.PROTOCOL_TLSv1)
+            server_context.load_cert_chain(SIGNED_CERTFILE)
+            client_context = ssl.SSLContext(ssl.PROTOCOL_TLSv1)
+            client_context.verify_mode = ssl.CERT_REQUIRED
+            client_context.load_verify_locations(SIGNING_CA)
+            client_context.set_ciphers("RC4")
+            server_context.set_ciphers("AES:RC4")
+            stats = server_params_test(client_context, server_context)
+            ciphers = stats['server_shared_ciphers'][0]
+            self.assertGreater(len(ciphers), 0)
+            for name, tls_version, bits in ciphers:
+                self.assertIn("RC4", name.split("-"))
+
         def test_read_write_after_close_raises_valuerror(self):
             context = ssl.SSLContext(ssl.PROTOCOL_SSLv23)
             context.verify_mode = ssl.CERT_REQUIRED
@@ -2886,6 +3271,23 @@ else:
                 self.assertRaises(ValueError, s.read, 1024)
                 self.assertRaises(ValueError, s.write, b'hello')
 
+        def test_sendfile(self):
+            TEST_DATA = b"x" * 512
+            with open(support.TESTFN, 'wb') as f:
+                f.write(TEST_DATA)
+            self.addCleanup(support.unlink, support.TESTFN)
+            context = ssl.SSLContext(ssl.PROTOCOL_SSLv23)
+            context.verify_mode = ssl.CERT_REQUIRED
+            context.load_verify_locations(CERTFILE)
+            context.load_cert_chain(CERTFILE)
+            server = ThreadedEchoServer(context=context, chatty=False)
+            with server:
+                with context.wrap_socket(socket.socket()) as s:
+                    s.connect((HOST, server.port))
+                    with open(support.TESTFN, 'rb') as file:
+                        s.sendfile(file)
+                        self.assertEqual(s.recv(1024), TEST_DATA)
+
 
 def test_main(verbose=False):
     if support.verbose:
@@ -2919,10 +3321,11 @@ def test_main(verbose=False):
         if not os.path.exists(filename):
             raise support.TestFailed("Can't read certificate file %r" % filename)
 
-    tests = [ContextTests, BasicSocketTests, SSLErrorTests]
+    tests = [ContextTests, BasicSocketTests, SSLErrorTests, MemoryBIOTests]
 
     if support.is_resource_enabled('network'):
         tests.append(NetworkedTests)
+        tests.append(NetworkedBIOTests)
 
     if _have_threads:
         thread_info = support.threading_setup()
diff --git a/Lib/test/test_stat.py b/Lib/test/test_stat.py
index af6ced4204..f1a5938a39 100644
--- a/Lib/test/test_stat.py
+++ b/Lib/test/test_stat.py
@@ -1,5 +1,6 @@
 import unittest
 import os
+import sys
 from test.support import TESTFN, import_fresh_module
 
 c_stat = import_fresh_module('stat', fresh=['_stat'])
@@ -52,6 +53,26 @@ class TestFilemode:
         'S_IWOTH': 0o002,
         'S_IXOTH': 0o001}
 
+    # defined by the Windows API documentation
+    file_attributes = {
+        'FILE_ATTRIBUTE_ARCHIVE': 32,
+        'FILE_ATTRIBUTE_COMPRESSED': 2048,
+        'FILE_ATTRIBUTE_DEVICE': 64,
+        'FILE_ATTRIBUTE_DIRECTORY': 16,
+        'FILE_ATTRIBUTE_ENCRYPTED': 16384,
+        'FILE_ATTRIBUTE_HIDDEN': 2,
+        'FILE_ATTRIBUTE_INTEGRITY_STREAM': 32768,
+        'FILE_ATTRIBUTE_NORMAL': 128,
+        'FILE_ATTRIBUTE_NOT_CONTENT_INDEXED': 8192,
+        'FILE_ATTRIBUTE_NO_SCRUB_DATA': 131072,
+        'FILE_ATTRIBUTE_OFFLINE': 4096,
+        'FILE_ATTRIBUTE_READONLY': 1,
+        'FILE_ATTRIBUTE_REPARSE_POINT': 1024,
+        'FILE_ATTRIBUTE_SPARSE_FILE': 512,
+        'FILE_ATTRIBUTE_SYSTEM': 4,
+        'FILE_ATTRIBUTE_TEMPORARY': 256,
+        'FILE_ATTRIBUTE_VIRTUAL': 65536}
+
     def setUp(self):
         try:
             os.remove(TESTFN)
@@ -185,6 +206,14 @@ class TestFilemode:
             self.assertTrue(callable(func))
             self.assertEqual(func(0), 0)
 
+    @unittest.skipUnless(sys.platform == "win32",
+                         "FILE_ATTRIBUTE_* constants are Win32 specific")
+    def test_file_attribute_constants(self):
+        for key, value in sorted(self.file_attributes.items()):
+            self.assertTrue(hasattr(self.statmod, key), key)
+            modvalue = getattr(self.statmod, key)
+            self.assertEqual(value, modvalue, key)
+
 
 class TestFilemodeCStat(TestFilemode, unittest.TestCase):
     statmod = c_stat
diff --git a/Lib/test/test_subprocess.py b/Lib/test/test_subprocess.py
index 08af71faad..460876f410 100644
--- a/Lib/test/test_subprocess.py
+++ b/Lib/test/test_subprocess.py
@@ -2421,25 +2421,6 @@ class ProcessTestCaseNoPoll(ProcessTestCase):
         ProcessTestCase.tearDown(self)
 
 
-class HelperFunctionTests(unittest.TestCase):
-    @unittest.skipIf(mswindows, "errno and EINTR make no sense on windows")
-    def test_eintr_retry_call(self):
-        record_calls = []
-        def fake_os_func(*args):
-            record_calls.append(args)
-            if len(record_calls) == 2:
-                raise OSError(errno.EINTR, "fake interrupted system call")
-            return tuple(reversed(args))
-
-        self.assertEqual((999, 256),
-                         subprocess._eintr_retry_call(fake_os_func, 256, 999))
-        self.assertEqual([(256, 999)], record_calls)
-        # This time there will be an EINTR so it will loop once.
-        self.assertEqual((666,),
-                         subprocess._eintr_retry_call(fake_os_func, 666))
-        self.assertEqual([(256, 999), (666,), (666,)], record_calls)
-
-
 @unittest.skipUnless(mswindows, "Windows-specific tests")
 class CommandsWithSpaces (BaseTestCase):
 
@@ -2528,7 +2509,6 @@ def test_main():
                   Win32ProcessTestCase,
                   CommandTests,
                   ProcessTestCaseNoPoll,
-                  HelperFunctionTests,
                   CommandsWithSpaces,
                   ContextManagerTests,
                   )
diff --git a/Lib/test/test_support.py b/Lib/test/test_support.py
index 03ce9d1931..a02d2f4f6f 100644
--- a/Lib/test/test_support.py
+++ b/Lib/test/test_support.py
@@ -85,7 +85,7 @@ class TestSupport(unittest.TestCase):
     def test_bind_port(self):
         s = socket.socket()
         support.bind_port(s)
-        s.listen(1)
+        s.listen()
         s.close()
 
     # Tests for temp_dir()
diff --git a/Lib/test/test_sys.py b/Lib/test/test_sys.py
index 2f66eb71d2..ed6b47d2e4 100644
--- a/Lib/test/test_sys.py
+++ b/Lib/test/test_sys.py
@@ -636,6 +636,53 @@ class SysModuleTest(unittest.TestCase):
             expected = None
         self.check_fsencoding(fs_encoding, expected)
 
+    def c_locale_get_error_handler(self, isolated=False, encoding=None):
+        # Force the POSIX locale
+        env = os.environ.copy()
+        env["LC_ALL"] = "C"
+        code = '\n'.join((
+            'import sys',
+            'def dump(name):',
+            '    std = getattr(sys, name)',
+            '    print("%s: %s" % (name, std.errors))',
+            'dump("stdin")',
+            'dump("stdout")',
+            'dump("stderr")',
+        ))
+        args = [sys.executable, "-c", code]
+        if isolated:
+            args.append("-I")
+        elif encoding:
+            env['PYTHONIOENCODING'] = encoding
+        p = subprocess.Popen(args,
+                              stdout=subprocess.PIPE,
+                              stderr=subprocess.STDOUT,
+                              env=env,
+                              universal_newlines=True)
+        stdout, stderr = p.communicate()
+        return stdout
+
+    def test_c_locale_surrogateescape(self):
+        out = self.c_locale_get_error_handler(isolated=True)
+        self.assertEqual(out,
+                         'stdin: surrogateescape\n'
+                         'stdout: surrogateescape\n'
+                         'stderr: backslashreplace\n')
+
+        # replace the default error handler
+        out = self.c_locale_get_error_handler(encoding=':strict')
+        self.assertEqual(out,
+                         'stdin: strict\n'
+                         'stdout: strict\n'
+                         'stderr: backslashreplace\n')
+
+        # force the encoding
+        out = self.c_locale_get_error_handler(encoding='iso8859-1')
+        self.assertEqual(out,
+                         'stdin: surrogateescape\n'
+                         'stdout: surrogateescape\n'
+                         'stderr: backslashreplace\n')
+
     def test_implementation(self):
         # This test applies to all implementations equally.
 
@@ -698,6 +745,27 @@ class SysModuleTest(unittest.TestCase):
         c = sys.getallocatedblocks()
         self.assertIn(c, range(b - 50, b + 50))
 
+    def test_is_finalizing(self):
+        self.assertIs(sys.is_finalizing(), False)
+        # Don't use the atexit module because _Py_Finalizing is only set
+        # after calling atexit callbacks
+        code = """if 1:
+            import sys
+
+            class AtExit:
+                is_finalizing = sys.is_finalizing
+                print = print
+
+                def __del__(self):
+                    self.print(self.is_finalizing(), flush=True)
+
+            # Keep a reference in the __main__ module namespace, so the
+            # AtExit destructor will be called at Python exit
+            ref = AtExit()
+        """
+        rc, stdout, stderr = assert_python_ok('-c', code)
+        self.assertEqual(stdout.rstrip(), b'True')
+
 
 @test.support.cpython_only
 class SizeofTest(unittest.TestCase):
@@ -770,7 +838,7 @@ class SizeofTest(unittest.TestCase):
         # buffer
         # XXX
         # builtin_function_or_method
-        check(len, size('3P')) # XXX check layout
+        check(len, size('4P')) # XXX check layout
         # bytearray
         samples = [b'', b'u'*100000]
         for sample in samples:
@@ -871,7 +939,7 @@ class SizeofTest(unittest.TestCase):
             check(bar, size('PP'))
         # generator
         def get_gen(): yield 1
-        check(get_gen(), size('Pb2P'))
+        check(get_gen(), size('Pb2PPP'))
         # iterator
         check(iter('abc'), size('lP'))
         # callable-iterator
@@ -898,7 +966,7 @@ class SizeofTest(unittest.TestCase):
         check(int(PyLong_BASE**2-1), vsize('') + 2*self.longdigit)
         check(int(PyLong_BASE**2), vsize('') + 3*self.longdigit)
         # memoryview
-        check(memoryview(b''), size('Pnin 2P2n2i5P 3cPn'))
+        check(memoryview(b''), size('Pnin 2P2n2i5P Pn'))
         # module
         check(unittest, size('PnPPP'))
         # None
@@ -927,7 +995,7 @@ class SizeofTest(unittest.TestCase):
         # frozenset
         PySet_MINSIZE = 8
         samples = [[], range(10), range(50)]
-        s = size('3n2P' + PySet_MINSIZE*'nP' + 'nP')
+        s = size('3nP' + PySet_MINSIZE*'nP' + '2nP')
         for sample in samples:
             minused = len(sample)
             if minused == 0: tmp = 1
@@ -958,7 +1026,7 @@ class SizeofTest(unittest.TestCase):
         check(int, s)
         # (PyTypeObject + PyNumberMethods + PyMappingMethods +
         #  PySequenceMethods + PyBufferProcs + 4P)
-        s = vsize('P2n15Pl4Pn9Pn11PIP') + struct.calcsize('34P 3P 10P 2P 4P')
+        s = vsize('P2n17Pl4Pn9Pn11PIP') + struct.calcsize('34P 3P 10P 2P 4P')
         # Separate block for PyDictKeysObject with 4 entries
         s += struct.calcsize("2nPn") + 4*struct.calcsize("n2P")
         # class
diff --git a/Lib/test/test_sys_setprofile.py b/Lib/test/test_sys_setprofile.py
index 9816e3ed64..e59320b158 100644
--- a/Lib/test/test_sys_setprofile.py
+++ b/Lib/test/test_sys_setprofile.py
@@ -260,7 +260,6 @@ class ProfileHookTestCase(TestCaseBase):
         def f():
             for i in range(2):
                 yield i
-            raise StopIteration
         def g(p):
             for i in f():
                 pass
diff --git a/Lib/test/test_tarfile.py b/Lib/test/test_tarfile.py
index c135304f40..01d1a922ee 100644
--- a/Lib/test/test_tarfile.py
+++ b/Lib/test/test_tarfile.py
@@ -285,6 +285,18 @@ class ListTest(ReadTest, unittest.TestCase):
         self.assertIn(b'pax' + (b'/123' * 125) + b'/longlink link to pax' +
                       (b'/123' * 125) + b'/longname', out)
 
+    def test_list_members(self):
+        tio = io.TextIOWrapper(io.BytesIO(), 'ascii', newline='\n')
+        def members(tar):
+            for tarinfo in tar.getmembers():
+                if 'reg' in tarinfo.name:
+                    yield tarinfo
+        with support.swap_attr(sys, 'stdout', tio):
+            self.tar.list(verbose=False, members=members(self.tar))
+        out = tio.detach().getvalue()
+        self.assertIn(b'ustar/regtype', out)
+        self.assertNotIn(b'ustar/conttype', out)
+
 
 class GzipListTest(GzipTest, ListTest):
     pass
@@ -1416,6 +1428,88 @@ class GNUWriteTest(unittest.TestCase):
                    ("longlnk/" * 127) + "longlink_")
 
 
+class CreateTest(TarTest, unittest.TestCase):
+
+    prefix = "x:"
+
+    file_path = os.path.join(TEMPDIR, "spameggs42")
+
+    def setUp(self):
+        support.unlink(tmpname)
+
+    @classmethod
+    def setUpClass(cls):
+        with open(cls.file_path, "wb") as fobj:
+            fobj.write(b"aaa")
+
+    @classmethod
+    def tearDownClass(cls):
+        support.unlink(cls.file_path)
+
+    def test_create(self):
+        with tarfile.open(tmpname, self.mode) as tobj:
+            tobj.add(self.file_path)
+
+        with self.taropen(tmpname) as tobj:
+            names = tobj.getnames()
+        self.assertEqual(len(names), 1)
+        self.assertIn('spameggs42', names[0])
+
+    def test_create_existing(self):
+        with tarfile.open(tmpname, self.mode) as tobj:
+            tobj.add(self.file_path)
+
+        with self.assertRaises(FileExistsError):
+            tobj = tarfile.open(tmpname, self.mode)
+
+        with self.taropen(tmpname) as tobj:
+            names = tobj.getnames()
+        self.assertEqual(len(names), 1)
+        self.assertIn('spameggs42', names[0])
+
+    def test_create_taropen(self):
+        with self.taropen(tmpname, "x") as tobj:
+            tobj.add(self.file_path)
+
+        with self.taropen(tmpname) as tobj:
+            names = tobj.getnames()
+        self.assertEqual(len(names), 1)
+        self.assertIn('spameggs42', names[0])
+
+    def test_create_existing_taropen(self):
+        with self.taropen(tmpname, "x") as tobj:
+            tobj.add(self.file_path)
+
+        with self.assertRaises(FileExistsError):
+            with self.taropen(tmpname, "x"):
+                pass
+
+        with self.taropen(tmpname) as tobj:
+            names = tobj.getnames()
+        self.assertEqual(len(names), 1)
+        self.assertIn("spameggs42", names[0])
+
+
+class GzipCreateTest(GzipTest, CreateTest):
+    pass
+
+
+class Bz2CreateTest(Bz2Test, CreateTest):
+    pass
+
+
+class LzmaCreateTest(LzmaTest, CreateTest):
+    pass
+
+
+class CreateWithXModeTest(CreateTest):
+
+    prefix = "x"
+
+    test_create_taropen = None
+    test_create_existing_taropen = None
+
+
 @unittest.skipUnless(hasattr(os, "link"), "Missing hardlink implementation")
 class HardlinkTest(unittest.TestCase):
     # Test the creation of LNKTYPE (hardlink) members in an archive.
diff --git a/Lib/test/test_tcl.py b/Lib/test/test_tcl.py
index da8f6299d6..d0251aa339 100644
--- a/Lib/test/test_tcl.py
+++ b/Lib/test/test_tcl.py
@@ -415,6 +415,8 @@ class TclTest(unittest.TestCase):
             # XXX NaN representation can be not parsable by float()
         self.assertEqual(passValue((1, '2', (3.4,))),
                          (1, '2', (3.4,)) if self.wantobjects else '1 2 3.4')
+        self.assertEqual(passValue(['a', ['b', 'c']]),
+                         ('a', ('b', 'c')) if self.wantobjects else 'a {b c}')
 
     def test_user_command(self):
         result = None
@@ -466,6 +468,7 @@ class TclTest(unittest.TestCase):
         # XXX NaN representation can be not parsable by float()
         check((), '')
         check((1, (2,), (3, 4), '5 6', ()), '1 2 {3 4} {5 6} {}')
+        check([1, [2,], [3, 4], '5 6', []], '1 2 {3 4} {5 6} {}')
 
     def test_splitlist(self):
         splitlist = self.interp.tk.splitlist
@@ -491,12 +494,15 @@ class TclTest(unittest.TestCase):
             ('a 3.4', ('a', '3.4')),
             (('a', 3.4), ('a', 3.4)),
             ((), ()),
+            ([], ()),
+            (['a', ['b', 'c']], ('a', ['b', 'c'])),
             (call('list', 1, '2', (3.4,)),
                 (1, '2', (3.4,)) if self.wantobjects else
                 ('1', '2', '3.4')),
         ]
+        tk_patchlevel = get_tk_patchlevel()
         if tcl_version >= (8, 5):
-            if not self.wantobjects or get_tk_patchlevel() < (8, 5, 5):
+            if not self.wantobjects or tk_patchlevel < (8, 5, 5):
                 # Before 8.5.5 dicts were converted to lists through string
                 expected = ('12', '\u20ac', '\xe2\x82\xac', '3.4')
             else:
@@ -505,8 +511,11 @@ class TclTest(unittest.TestCase):
                 (call('dict', 'create', 12, '\u20ac', b'\xe2\x82\xac', (3.4,)),
                     expected),
             ]
+        dbg_info = ('want objects? %s, Tcl version: %s, Tk patchlevel: %s'
+                    % (self.wantobjects, tcl_version, tk_patchlevel))
         for arg, res in testcases:
-            self.assertEqual(splitlist(arg), res, msg=arg)
+            self.assertEqual(splitlist(arg), res,
+                             'arg=%a, %s' % (arg, dbg_info))
         self.assertRaises(TclError, splitlist, '{')
 
     def test_split(self):
@@ -538,6 +547,9 @@ class TclTest(unittest.TestCase):
             (('a', 3.4), ('a', 3.4)),
             (('a', (2, 3.4)), ('a', (2, 3.4))),
             ((), ()),
+            ([], ()),
+            (['a', 'b c'], ('a', ('b', 'c'))),
+            (['a', ['b', 'c']], ('a', ('b', 'c'))),
             (call('list', 1, '2', (3.4,)),
                 (1, '2', (3.4,)) if self.wantobjects else
                 ('1', '2', '3.4')),
diff --git a/Lib/test/test_telnetlib.py b/Lib/test/test_telnetlib.py
index ee1c35705b..e1ef99af3a 100644
--- a/Lib/test/test_telnetlib.py
+++ b/Lib/test/test_telnetlib.py
@@ -11,7 +11,7 @@ threading = support.import_module('threading')
 HOST = support.HOST
 
 def server(evt, serv):
-    serv.listen(5)
+    serv.listen()
     evt.set()
     try:
         conn, addr = serv.accept()
diff --git a/Lib/test/test_threaded_import.py b/Lib/test/test_threaded_import.py
index 192fa08a26..5bf670c815 100644
--- a/Lib/test/test_threaded_import.py
+++ b/Lib/test/test_threaded_import.py
@@ -115,12 +115,18 @@ class ThreadedImportTests(unittest.TestCase):
             errors = []
             done_tasks = []
             done.clear()
+            t0 = time.monotonic()
             for i in range(N):
                 t = threading.Thread(target=task,
                                      args=(N, done, done_tasks, errors,))
                 t.start()
-            self.assertTrue(done.wait(60))
-            self.assertFalse(errors)
+            completed = done.wait(10 * 60)
+            dt = time.monotonic() - t0
+            if verbose:
+                print("%.1f ms" % (dt*1e3), flush=True, end=" ")
+            dbg_info = 'done: %s/%s' % (len(done_tasks), N)
+            self.assertFalse(errors, dbg_info)
+            self.assertTrue(completed, dbg_info)
             if verbose:
                 print("OK.")
 
diff --git a/Lib/test/test_timeit.py b/Lib/test/test_timeit.py
index 09e76e023d..267d2c80c9 100644
--- a/Lib/test/test_timeit.py
+++ b/Lib/test/test_timeit.py
@@ -98,9 +98,10 @@ class TestTimeit(unittest.TestCase):
     def fake_callable_stmt(self):
         self.fake_timer.inc()
 
-    def timeit(self, stmt, setup, number=None):
+    def timeit(self, stmt, setup, number=None, globals=None):
         self.fake_timer = FakeTimer()
-        t = timeit.Timer(stmt=stmt, setup=setup, timer=self.fake_timer)
+        t = timeit.Timer(stmt=stmt, setup=setup, timer=self.fake_timer,
+                globals=globals)
         kwargs = {}
         if number is None:
             number = DEFAULT_NUMBER
@@ -139,6 +140,17 @@ class TestTimeit(unittest.TestCase):
                 timer=FakeTimer())
         self.assertEqual(delta_time, 0)
 
+    def test_timeit_globals_args(self):
+        global _global_timer
+        _global_timer = FakeTimer()
+        t = timeit.Timer(stmt='_global_timer.inc()', timer=_global_timer)
+        self.assertRaises(NameError, t.timeit, number=3)
+        timeit.timeit(stmt='_global_timer.inc()', timer=_global_timer,
+                      globals=globals(), number=3)
+        local_timer = FakeTimer()
+        timeit.timeit(stmt='local_timer.inc()', timer=local_timer,
+                      globals=locals(), number=3)
+
     def repeat(self, stmt, setup, repeat=None, number=None):
         self.fake_timer = FakeTimer()
         t = timeit.Timer(stmt=stmt, setup=setup, timer=self.fake_timer)
diff --git a/Lib/test/test_timeout.py b/Lib/test/test_timeout.py
index 703c43ab2b..3c75dcc6f9 100644
--- a/Lib/test/test_timeout.py
+++ b/Lib/test/test_timeout.py
@@ -243,14 +243,14 @@ class TCPTimeoutTestCase(TimeoutTestCase):
     def testAcceptTimeout(self):
         # Test accept() timeout
         support.bind_port(self.sock, self.localhost)
-        self.sock.listen(5)
+        self.sock.listen()
         self._sock_operation(1, 1.5, 'accept')
 
     def testSend(self):
         # Test send() timeout
         with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as serv:
             support.bind_port(serv, self.localhost)
-            serv.listen(5)
+            serv.listen()
             self.sock.connect(serv.getsockname())
             # Send a lot of data in order to bypass buffering in the TCP stack.
             self._sock_operation(100, 1.5, 'send', b"X" * 200000)
@@ -259,7 +259,7 @@ class TCPTimeoutTestCase(TimeoutTestCase):
         # Test sendto() timeout
         with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as serv:
             support.bind_port(serv, self.localhost)
-            serv.listen(5)
+            serv.listen()
             self.sock.connect(serv.getsockname())
             # The address argument is ignored since we already connected.
             self._sock_operation(100, 1.5, 'sendto', b"X" * 200000,
@@ -269,7 +269,7 @@ class TCPTimeoutTestCase(TimeoutTestCase):
         # Test sendall() timeout
         with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as serv:
             support.bind_port(serv, self.localhost)
-            serv.listen(5)
+            serv.listen()
             self.sock.connect(serv.getsockname())
             # Send a lot of data in order to bypass buffering in the TCP stack.
             self._sock_operation(100, 1.5, 'sendall', b"X" * 200000)
diff --git a/Lib/test/test_tokenize.py b/Lib/test/test_tokenize.py
index 38611a79ee..8f74a06df5 100644
--- a/Lib/test/test_tokenize.py
+++ b/Lib/test/test_tokenize.py
@@ -464,7 +464,7 @@ Additive
 
 Multiplicative
 
-    >>> dump_tokens("x = 1//1*1/5*12%0x12")
+    >>> dump_tokens("x = 1//1*1/5*12%0x12@42")
     ENCODING   'utf-8'       (0, 0) (0, 0)
     NAME       'x'           (1, 0) (1, 1)
     OP         '='           (1, 2) (1, 3)
@@ -479,6 +479,8 @@ Multiplicative
     NUMBER     '12'          (1, 13) (1, 15)
     OP         '%'           (1, 15) (1, 16)
     NUMBER     '0x12'        (1, 16) (1, 20)
+    OP         '@'           (1, 20) (1, 21)
+    NUMBER     '42'          (1, 21) (1, 23)
 
 Unary
 
@@ -1154,6 +1156,7 @@ class TestTokenize(TestCase):
         self.assertExactTypeEqual('//', token.DOUBLESLASH)
         self.assertExactTypeEqual('//=', token.DOUBLESLASHEQUAL)
         self.assertExactTypeEqual('@', token.AT)
+        self.assertExactTypeEqual('@=', token.ATEQUAL)
 
         self.assertExactTypeEqual('a**2+b**2==c**2',
                                   NAME, token.DOUBLESTAR, NUMBER,
diff --git a/Lib/test/test_trace.py b/Lib/test/test_trace.py
index 1cec710ee5..05bf274ca8 100644
--- a/Lib/test/test_trace.py
+++ b/Lib/test/test_trace.py
@@ -10,7 +10,6 @@ from trace import CoverageResults, Trace
 
 from test.tracedmodules import testmod
 
-
 #------------------------------- Utilities -----------------------------------#
 
 def fix_ext_py(filename):
@@ -224,6 +223,11 @@ class TestFuncs(unittest.TestCase):
         self.addCleanup(sys.settrace, sys.gettrace())
         self.tracer = Trace(count=0, trace=0, countfuncs=1)
         self.filemod = my_file_and_modname()
+        self._saved_tracefunc = sys.gettrace()
+
+    def tearDown(self):
+        if self._saved_tracefunc is not None:
+            sys.settrace(self._saved_tracefunc)
 
     def test_simple_caller(self):
         self.tracer.runfunc(traced_func_simple_caller, 1)
diff --git a/Lib/test/test_traceback.py b/Lib/test/test_traceback.py
index c29556354e..6bd6fa6303 100644
--- a/Lib/test/test_traceback.py
+++ b/Lib/test/test_traceback.py
@@ -6,6 +6,8 @@ import unittest
 import re
 from test.support import run_unittest, Error, captured_output
 from test.support import TESTFN, unlink, cpython_only
+from test.script_helper import assert_python_ok
+import textwrap
 
 import traceback
 
@@ -92,9 +94,9 @@ class SyntaxTracebackCases(unittest.TestCase):
         self.assertEqual(len(err), 1)
         str_value = '<unprintable %s object>' % X.__name__
         if X.__module__ in ('__main__', 'builtins'):
-            str_name = X.__name__
+            str_name = X.__qualname__
         else:
-            str_name = '.'.join([X.__module__, X.__name__])
+            str_name = '.'.join([X.__module__, X.__qualname__])
         self.assertEqual(err[0], "%s: %s\n" % (str_name, str_value))
 
     def test_without_exception(self):
@@ -169,6 +171,37 @@ class SyntaxTracebackCases(unittest.TestCase):
         # Issue #18960: coding spec should has no effect
         do_test("0\n# coding: GBK\n", "h\xe9 ho", 'utf-8', 5)
 
+    def test_print_traceback_at_exit(self):
+        # Issue #22599: Ensure that it is possible to use the traceback module
+        # to display an exception at Python exit
+        code = textwrap.dedent("""
+            import sys
+            import traceback
+
+            class PrintExceptionAtExit(object):
+                def __init__(self):
+                    try:
+                        x = 1 / 0
+                    except Exception:
+                        self.exc_info = sys.exc_info()
+                        # self.exc_info[1] (traceback) contains frames:
+                        # explicitly clear the reference to self in the current
+                        # frame to break a reference cycle
+                        self = None
+
+                def __del__(self):
+                    traceback.print_exception(*self.exc_info)
+
+            # Keep a reference in the module namespace to call the destructor
+            # when the module is unloaded
+            obj = PrintExceptionAtExit()
+        """)
+        rc, stdout, stderr = assert_python_ok('-c', code)
+        expected = [b'Traceback (most recent call last):',
+                    b'  File "<string>", line 8, in __init__',
+                    b'ZeroDivisionError: division by zero']
+        self.assertEqual(stderr.splitlines(), expected)
+
 
 class TracebackFormatTests(unittest.TestCase):
 
diff --git a/Lib/test/test_tracemalloc.py b/Lib/test/test_tracemalloc.py
index 48ccab28b8..19d3fd8dda 100644
--- a/Lib/test/test_tracemalloc.py
+++ b/Lib/test/test_tracemalloc.py
@@ -755,7 +755,7 @@ class TestCommandLine(unittest.TestCase):
         stdout = stdout.rstrip()
         self.assertEqual(stdout, b'False')
 
-    @unittest.skipIf(script_helper._interpreter_requires_environment(),
+    @unittest.skipIf(script_helper.interpreter_requires_environment(),
                      'Cannot run -E tests when PYTHON env vars are required.')
     def test_env_var_ignored_with_E(self):
         """PYTHON* environment variables must be ignored when -E is present."""
diff --git a/Lib/test/test_tuple.py b/Lib/test/test_tuple.py
index 51875a1cbd..d711116e37 100644
--- a/Lib/test/test_tuple.py
+++ b/Lib/test/test_tuple.py
@@ -6,6 +6,11 @@ import pickle
 class TupleTest(seq_tests.CommonTest):
     type2test = tuple
 
+    def test_getitem_error(self):
+        msg = "tuple indices must be integers or slices"
+        with self.assertRaisesRegex(TypeError, msg):
+            ()['a']
+
     def test_constructors(self):
         super().test_constructors()
         # calling built-in types without argument must return empty
@@ -203,6 +208,14 @@ class TupleTest(seq_tests.CommonTest):
         with self.assertRaises(TypeError):
             [3,] + T((1,2))
 
+    def test_lexicographic_ordering(self):
+        # Issue 21100
+        a = self.type2test([1, 2])
+        b = self.type2test([1, 2, 0])
+        c = self.type2test([1, 3])
+        self.assertLess(a, b)
+        self.assertLess(b, c)
+
 def test_main():
     support.run_unittest(TupleTest)
 
diff --git a/Lib/test/test_types.py b/Lib/test/test_types.py
index ec10752e6a..11d95465a8 100644
--- a/Lib/test/test_types.py
+++ b/Lib/test/test_types.py
@@ -343,6 +343,8 @@ class TypesTests(unittest.TestCase):
         self.assertRaises(ValueError, 3 .__format__, ",n")
         # can't have ',' with 'c'
         self.assertRaises(ValueError, 3 .__format__, ",c")
+        # can't have '#' with 'c'
+        self.assertRaises(ValueError, 3 .__format__, "#c")
 
         # ensure that only int and float type specifiers work
         for format_spec in ([chr(x) for x in range(ord('a'), ord('z')+1)] +
diff --git a/Lib/test/test_unicode.py b/Lib/test/test_unicode.py
index 7735a6bbaa..e4cd99b06f 100644
--- a/Lib/test/test_unicode.py
+++ b/Lib/test/test_unicode.py
@@ -8,6 +8,7 @@ Written by Marc-Andre Lemburg (mal@lemburg.com).
 import _string
 import codecs
 import itertools
+import operator
 import struct
 import sys
 import unittest
@@ -250,6 +251,7 @@ class UnicodeTest(string_tests.CommonTest,
                              {ord('a'): None, ord('b'): ''})
         self.checkequalnofix('xyyx', 'xzx', 'translate',
                              {ord('z'): 'yy'})
+
         # this needs maketrans()
         self.checkequalnofix('abababc', 'abababc', 'translate',
                              {'b': '<i>'})
@@ -259,6 +261,33 @@ class UnicodeTest(string_tests.CommonTest,
         tbl = self.type2test.maketrans('abc', 'xyz', 'd')
         self.checkequalnofix('xyzzy', 'abdcdcbdddd', 'translate', tbl)
 
+        # various tests switching from ASCII to latin1 or the opposite;
+        # same length, remove a letter, or replace with a longer string.
+        self.assertEqual("[a]".translate(str.maketrans('a', 'X')),
+                         "[X]")
+        self.assertEqual("[a]".translate(str.maketrans({'a': 'X'})),
+                         "[X]")
+        self.assertEqual("[a]".translate(str.maketrans({'a': None})),
+                         "[]")
+        self.assertEqual("[a]".translate(str.maketrans({'a': 'XXX'})),
+                         "[XXX]")
+        self.assertEqual("[a]".translate(str.maketrans({'a': '\xe9'})),
+                         "[\xe9]")
+        self.assertEqual("[a]".translate(str.maketrans({'a': '<\xe9>'})),
+                         "[<\xe9>]")
+        self.assertEqual("[\xe9]".translate(str.maketrans({'\xe9': 'a'})),
+                         "[a]")
+        self.assertEqual("[\xe9]".translate(str.maketrans({'\xe9': None})),
+                         "[]")
+
+        # invalid Unicode characters
+        invalid_char = 0x10ffff+1
+        for before in "a\xe9\u20ac\U0010ffff":
+            mapping = str.maketrans({before: invalid_char})
+            text = "[%s]" % before
+            self.assertRaises(ValueError, text.translate, mapping)
+
+        # errors
         self.assertRaises(TypeError, self.type2test.maketrans)
         self.assertRaises(ValueError, self.type2test.maketrans, 'abc', 'defg')
         self.assertRaises(TypeError, self.type2test.maketrans, 2, 'def')
@@ -1154,20 +1183,20 @@ class UnicodeTest(string_tests.CommonTest,
         self.assertEqual('%.2s' % "a\xe9\u20ac", 'a\xe9')
 
         #issue 19995
-        class PsuedoInt:
+        class PseudoInt:
             def __init__(self, value):
                 self.value = int(value)
             def __int__(self):
                 return self.value
             def __index__(self):
                 return self.value
-        class PsuedoFloat:
+        class PseudoFloat:
             def __init__(self, value):
                 self.value = float(value)
             def __int__(self):
                 return int(self.value)
-        pi = PsuedoFloat(3.1415)
-        letter_m = PsuedoInt(109)
+        pi = PseudoFloat(3.1415)
+        letter_m = PseudoInt(109)
         self.assertEqual('%x' % 42, '2a')
         self.assertEqual('%X' % 15, 'F')
         self.assertEqual('%o' % 9, '11')
@@ -1176,11 +1205,11 @@ class UnicodeTest(string_tests.CommonTest,
         self.assertEqual('%X' % letter_m, '6D')
         self.assertEqual('%o' % letter_m, '155')
         self.assertEqual('%c' % letter_m, 'm')
-        self.assertWarns(DeprecationWarning, '%x'.__mod__, pi),
-        self.assertWarns(DeprecationWarning, '%x'.__mod__, 3.14),
-        self.assertWarns(DeprecationWarning, '%X'.__mod__, 2.11),
-        self.assertWarns(DeprecationWarning, '%o'.__mod__, 1.79),
-        self.assertWarns(DeprecationWarning, '%c'.__mod__, pi),
+        self.assertRaisesRegex(TypeError, '%x format: an integer is required, not float', operator.mod, '%x', 3.14),
+        self.assertRaisesRegex(TypeError, '%X format: an integer is required, not float', operator.mod, '%X', 2.11),
+        self.assertRaisesRegex(TypeError, '%o format: an integer is required, not float', operator.mod, '%o', 1.79),
+        self.assertRaisesRegex(TypeError, '%x format: an integer is required, not PseudoFloat', operator.mod, '%x', pi),
+        self.assertRaises(TypeError, operator.mod, '%c', pi),
 
     def test_formatting_with_enum(self):
         # issue18780
diff --git a/Lib/test/test_unicodedata.py b/Lib/test/test_unicodedata.py
index 707b30e50c..f8788a0588 100644
--- a/Lib/test/test_unicodedata.py
+++ b/Lib/test/test_unicodedata.py
@@ -21,7 +21,7 @@ errors = 'surrogatepass'
 class UnicodeMethodsTest(unittest.TestCase):
 
     # update this, if the database changes
-    expectedchecksum = 'e74e878de71b6e780ffac271785c3cb58f6251f3'
+    expectedchecksum = '618e2c1a22ee79d2235319709f16c50f987ee21f'
 
     def test_method_checksum(self):
         h = hashlib.sha1()
@@ -79,8 +79,9 @@ class UnicodeDatabaseTest(unittest.TestCase):
 
 class UnicodeFunctionsTest(UnicodeDatabaseTest):
 
-    # update this, if the database changes
-    expectedchecksum = 'f0b74d26776331cc7bdc3a4698f037d73f2cee2b'
+    # Update this if the database changes. Make sure to do a full rebuild
+    # (e.g. 'make distclean && make') to get the correct checksum.
+    expectedchecksum = '585302895deead0c1c8478c51da9241d4efedca9'
     def test_function_checksum(self):
         data = []
         h = hashlib.sha1()
diff --git a/Lib/test/test_urllib.py b/Lib/test/test_urllib.py
index 4f38f0f039..fcd20738f8 100644
--- a/Lib/test/test_urllib.py
+++ b/Lib/test/test_urllib.py
@@ -10,7 +10,10 @@ import unittest
 from unittest.mock import patch
 from test import support
 import os
-import ssl
+try:
+    import ssl
+except ImportError:
+    ssl = None
 import sys
 import tempfile
 from nturl2path import url2pathname, pathname2url
@@ -380,6 +383,7 @@ Content-Type: text/html; charset=iso-8859-1
         with support.check_warnings(('',DeprecationWarning)):
             urllib.request.URLopener()
 
+    @unittest.skipUnless(ssl, "ssl module required")
     def test_cafile_and_context(self):
         context = ssl.create_default_context()
         with self.assertRaises(ValueError):
@@ -1346,7 +1350,7 @@ class URLopener_Tests(unittest.TestCase):
 #     serv.settimeout(3)
 #     serv.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
 #     serv.bind(("", 9093))
-#     serv.listen(5)
+#     serv.listen()
 #     try:
 #         conn, addr = serv.accept()
 #         conn.send("1 Hola mundo\n")
diff --git a/Lib/test/test_urllib2.py b/Lib/test/test_urllib2.py
index c746b9a6bb..3182390c42 100644
--- a/Lib/test/test_urllib2.py
+++ b/Lib/test/test_urllib2.py
@@ -1422,6 +1422,21 @@ class HandlerTests(unittest.TestCase):
             handler.do_open(conn, req)
         self.assertTrue(conn.fakesock.closed, "Connection not closed")
 
+    def test_auth_prior_handler(self):
+        pwd_manager = MockPasswordManager()
+        pwd_manager.add_password(None, 'https://example.com',
+                                 'somebody', 'verysecret')
+        auth_prior_handler = urllib.request.HTTPBasicPriorAuthHandler(
+            pwd_manager)
+        http_hand = MockHTTPSHandler()
+
+        opener = OpenerDirector()
+        opener.add_handler(http_hand)
+        opener.add_handler(auth_prior_handler)
+
+        req = Request("https://example.com")
+        opener.open(req)
+        self.assertNotIn('Authorization', http_hand.httpconn.req_headers)
 
 class MiscTests(unittest.TestCase):
 
diff --git a/Lib/test/test_urllibnet.py b/Lib/test/test_urllibnet.py
index 4c8ba2d22c..42ebb6e60b 100644
--- a/Lib/test/test_urllibnet.py
+++ b/Lib/test/test_urllibnet.py
@@ -91,7 +91,8 @@ class urlopenNetworkTests(unittest.TestCase):
         # test getcode() with the fancy opener to get 404 error codes
         URL = "http://www.example.com/XXXinvalidXXX"
         with support.transient_internet(URL):
-            open_url = urllib.request.FancyURLopener().open(URL)
+            with self.assertWarns(DeprecationWarning):
+                open_url = urllib.request.FancyURLopener().open(URL)
             try:
                 code = open_url.getcode()
             finally:
diff --git a/Lib/test/test_urlparse.py b/Lib/test/test_urlparse.py
index 393481148d..cb323d3423 100644
--- a/Lib/test/test_urlparse.py
+++ b/Lib/test/test_urlparse.py
@@ -211,10 +211,6 @@ class UrlParseTestCase(unittest.TestCase):
 
         # "abnormal" cases from RFC 1808:
         self.checkJoin(RFC1808_BASE, '', 'http://a/b/c/d;p?q#f')
-        self.checkJoin(RFC1808_BASE, '../../../g', 'http://a/../g')
-        self.checkJoin(RFC1808_BASE, '../../../../g', 'http://a/../../g')
-        self.checkJoin(RFC1808_BASE, '/./g', 'http://a/./g')
-        self.checkJoin(RFC1808_BASE, '/../g', 'http://a/../g')
         self.checkJoin(RFC1808_BASE, 'g.', 'http://a/b/c/g.')
         self.checkJoin(RFC1808_BASE, '.g', 'http://a/b/c/.g')
         self.checkJoin(RFC1808_BASE, 'g..', 'http://a/b/c/g..')
@@ -229,6 +225,13 @@ class UrlParseTestCase(unittest.TestCase):
         #self.checkJoin(RFC1808_BASE, 'http:g', 'http:g')
         #self.checkJoin(RFC1808_BASE, 'http:', 'http:')
 
+        # XXX: The following tests are no longer compatible with RFC3986
+        # self.checkJoin(RFC1808_BASE, '../../../g', 'http://a/../g')
+        # self.checkJoin(RFC1808_BASE, '../../../../g', 'http://a/../../g')
+        # self.checkJoin(RFC1808_BASE, '/./g', 'http://a/./g')
+        # self.checkJoin(RFC1808_BASE, '/../g', 'http://a/../g')
+
+
     def test_RFC2368(self):
         # Issue 11467: path that starts with a number is not parsed correctly
         self.assertEqual(urllib.parse.urlparse('mailto:1337@example.org'),
@@ -259,10 +262,6 @@ class UrlParseTestCase(unittest.TestCase):
         self.checkJoin(RFC2396_BASE, '../../', 'http://a/')
         self.checkJoin(RFC2396_BASE, '../../g', 'http://a/g')
         self.checkJoin(RFC2396_BASE, '', RFC2396_BASE)
-        self.checkJoin(RFC2396_BASE, '../../../g', 'http://a/../g')
-        self.checkJoin(RFC2396_BASE, '../../../../g', 'http://a/../../g')
-        self.checkJoin(RFC2396_BASE, '/./g', 'http://a/./g')
-        self.checkJoin(RFC2396_BASE, '/../g', 'http://a/../g')
         self.checkJoin(RFC2396_BASE, 'g.', 'http://a/b/c/g.')
         self.checkJoin(RFC2396_BASE, '.g', 'http://a/b/c/.g')
         self.checkJoin(RFC2396_BASE, 'g..', 'http://a/b/c/g..')
@@ -278,10 +277,17 @@ class UrlParseTestCase(unittest.TestCase):
         self.checkJoin(RFC2396_BASE, 'g#s/./x', 'http://a/b/c/g#s/./x')
         self.checkJoin(RFC2396_BASE, 'g#s/../x', 'http://a/b/c/g#s/../x')
 
+        # XXX: The following tests are no longer compatible with RFC3986
+        # self.checkJoin(RFC2396_BASE, '../../../g', 'http://a/../g')
+        # self.checkJoin(RFC2396_BASE, '../../../../g', 'http://a/../../g')
+        # self.checkJoin(RFC2396_BASE, '/./g', 'http://a/./g')
+        # self.checkJoin(RFC2396_BASE, '/../g', 'http://a/../g')
+
+
     def test_RFC3986(self):
         # Test cases from RFC3986
         self.checkJoin(RFC3986_BASE, '?y','http://a/b/c/d;p?y')
-        self.checkJoin(RFC2396_BASE, ';x', 'http://a/b/c/;x')
+        self.checkJoin(RFC3986_BASE, ';x', 'http://a/b/c/;x')
         self.checkJoin(RFC3986_BASE, 'g:h','g:h')
         self.checkJoin(RFC3986_BASE, 'g','http://a/b/c/g')
         self.checkJoin(RFC3986_BASE, './g','http://a/b/c/g')
@@ -305,17 +311,17 @@ class UrlParseTestCase(unittest.TestCase):
         self.checkJoin(RFC3986_BASE, '../..','http://a/')
         self.checkJoin(RFC3986_BASE, '../../','http://a/')
         self.checkJoin(RFC3986_BASE, '../../g','http://a/g')
+        self.checkJoin(RFC3986_BASE, '../../../g', 'http://a/g')
 
         #Abnormal Examples
 
         # The 'abnormal scenarios' are incompatible with RFC2986 parsing
         # Tests are here for reference.
 
-        #self.checkJoin(RFC3986_BASE, '../../../g','http://a/g')
-        #self.checkJoin(RFC3986_BASE, '../../../../g','http://a/g')
-        #self.checkJoin(RFC3986_BASE, '/./g','http://a/g')
-        #self.checkJoin(RFC3986_BASE, '/../g','http://a/g')
-
+        self.checkJoin(RFC3986_BASE, '../../../g','http://a/g')
+        self.checkJoin(RFC3986_BASE, '../../../../g','http://a/g')
+        self.checkJoin(RFC3986_BASE, '/./g','http://a/g')
+        self.checkJoin(RFC3986_BASE, '/../g','http://a/g')
         self.checkJoin(RFC3986_BASE, 'g.','http://a/b/c/g.')
         self.checkJoin(RFC3986_BASE, '.g','http://a/b/c/.g')
         self.checkJoin(RFC3986_BASE, 'g..','http://a/b/c/g..')
@@ -355,10 +361,8 @@ class UrlParseTestCase(unittest.TestCase):
         self.checkJoin(SIMPLE_BASE, '../g','http://a/b/g')
         self.checkJoin(SIMPLE_BASE, '../..','http://a/')
         self.checkJoin(SIMPLE_BASE, '../../g','http://a/g')
-        self.checkJoin(SIMPLE_BASE, '../../../g','http://a/../g')
         self.checkJoin(SIMPLE_BASE, './../g','http://a/b/g')
         self.checkJoin(SIMPLE_BASE, './g/.','http://a/b/c/g/')
-        self.checkJoin(SIMPLE_BASE, '/./g','http://a/./g')
         self.checkJoin(SIMPLE_BASE, 'g/./h','http://a/b/c/g/h')
         self.checkJoin(SIMPLE_BASE, 'g/../h','http://a/b/c/h')
         self.checkJoin(SIMPLE_BASE, 'http:g','http://a/b/c/g')
@@ -372,6 +376,22 @@ class UrlParseTestCase(unittest.TestCase):
         self.checkJoin('svn://pathtorepo/dir1', 'dir2', 'svn://pathtorepo/dir2')
         self.checkJoin('svn+ssh://pathtorepo/dir1', 'dir2', 'svn+ssh://pathtorepo/dir2')
 
+        # XXX: The following tests are no longer compatible with RFC3986
+        # self.checkJoin(SIMPLE_BASE, '../../../g','http://a/../g')
+        # self.checkJoin(SIMPLE_BASE, '/./g','http://a/./g')
+
+        # test for issue22118 duplicate slashes
+        self.checkJoin(SIMPLE_BASE + '/', 'foo', SIMPLE_BASE + '/foo')
+
+        # Non-RFC-defined tests, covering variations of base and trailing
+        # slashes
+        self.checkJoin('http://a/b/c/d/e/', '../../f/g/', 'http://a/b/c/f/g/')
+        self.checkJoin('http://a/b/c/d/e', '../../f/g/', 'http://a/b/f/g/')
+        self.checkJoin('http://a/b/c/d/e/', '/../../f/g/', 'http://a/f/g/')
+        self.checkJoin('http://a/b/c/d/e', '/../../f/g/', 'http://a/f/g/')
+        self.checkJoin('http://a/b/c/d/e/', '../../f/g', 'http://a/b/c/f/g')
+        self.checkJoin('http://a/b/', '../../f/g/', 'http://a/f/g/')
+
     def test_RFC2732(self):
         str_cases = [
             ('http://Test.python.org:5432/foo/', 'test.python.org', 5432),
diff --git a/Lib/test/test_uuid.py b/Lib/test/test_uuid.py
index 1e8cba30bd..fcb84540c1 100644
--- a/Lib/test/test_uuid.py
+++ b/Lib/test/test_uuid.py
@@ -1,9 +1,10 @@
-import unittest
+import unittest.mock
 from test import support
 import builtins
 import io
 import os
 import shutil
+import subprocess
 import uuid
 
 def importable(name):
@@ -412,28 +413,27 @@ class TestUUID(unittest.TestCase):
 class TestInternals(unittest.TestCase):
     @unittest.skipUnless(os.name == 'posix', 'requires Posix')
     def test_find_mac(self):
-        data = '''\
-
+        data = '''
 fake hwaddr
 cscotun0  Link encap:UNSPEC  HWaddr 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00
 eth0      Link encap:Ethernet  HWaddr 12:34:56:78:90:ab
 '''
-        def mock_popen(cmd):
-            return io.StringIO(data)
-
-        if shutil.which('ifconfig') is None:
-            path = os.pathsep.join(('/sbin', '/usr/sbin'))
-            if shutil.which('ifconfig', path=path) is None:
-                self.skipTest('requires ifconfig')
-
-        with support.swap_attr(os, 'popen', mock_popen):
-            mac = uuid._find_mac(
-                command='ifconfig',
-                args='',
-                hw_identifiers=['hwaddr'],
-                get_index=lambda x: x + 1,
-            )
-            self.assertEqual(mac, 0x1234567890ab)
+
+        popen = unittest.mock.MagicMock()
+        popen.stdout = io.BytesIO(data.encode())
+
+        with unittest.mock.patch.object(shutil, 'which',
+                                        return_value='/sbin/ifconfig'):
+            with unittest.mock.patch.object(subprocess, 'Popen',
+                                            return_value=popen):
+                mac = uuid._find_mac(
+                    command='ifconfig',
+                    args='',
+                    hw_identifiers=[b'hwaddr'],
+                    get_index=lambda x: x + 1,
+                )
+
+        self.assertEqual(mac, 0x1234567890ab)
 
     def check_node(self, node, requires=None, network=False):
         if requires and node is None:
@@ -454,6 +454,11 @@ eth0      Link encap:Ethernet  HWaddr 12:34:56:78:90:ab
         self.check_node(node, 'ifconfig', True)
 
     @unittest.skipUnless(os.name == 'posix', 'requires Posix')
+    def test_ip_getnode(self):
+        node = uuid._ip_getnode()
+        self.check_node(node, 'ip', True)
+
+    @unittest.skipUnless(os.name == 'posix', 'requires Posix')
     def test_arp_getnode(self):
         node = uuid._arp_getnode()
         self.check_node(node, 'arp', True)
diff --git a/Lib/test/test_wait3.py b/Lib/test/test_wait3.py
index f6a065d850..bb71481adc 100644
--- a/Lib/test/test_wait3.py
+++ b/Lib/test/test_wait3.py
@@ -18,7 +18,8 @@ class Wait3Test(ForkWait):
         # This many iterations can be required, since some previously run
         # tests (e.g. test_ctypes) could have spawned a lot of children
         # very quickly.
-        for i in range(30):
+        deadline = time.monotonic() + 10.0
+        while time.monotonic() <= deadline:
             # wait3() shouldn't hang, but some of the buildbots seem to hang
             # in the forking tests.  This is an attempt to fix the problem.
             spid, status, rusage = os.wait3(os.WNOHANG)
diff --git a/Lib/test/test_wait4.py b/Lib/test/test_wait4.py
index 352c11aade..b427a9b1a4 100644
--- a/Lib/test/test_wait4.py
+++ b/Lib/test/test_wait4.py
@@ -19,13 +19,14 @@ class Wait4Test(ForkWait):
             # Issue #11185: wait4 is broken on AIX and will always return 0
             # with WNOHANG.
             option = 0
-        for i in range(10):
+        deadline = time.monotonic() + 10.0
+        while time.monotonic() <= deadline:
             # wait4() shouldn't hang, but some of the buildbots seem to hang
             # in the forking tests.  This is an attempt to fix the problem.
             spid, status, rusage = os.wait4(cpid, option)
             if spid == cpid:
                 break
-            time.sleep(1.0)
+            time.sleep(0.1)
         self.assertEqual(spid, cpid)
         self.assertEqual(status, 0, "cause = %d, exit = %d" % (status&0xff, status>>8))
         self.assertTrue(rusage)
diff --git a/Lib/test/test_warnings.py b/Lib/test/test_warnings.py
index fb01b83e0c..9ac2139e33 100644
--- a/Lib/test/test_warnings.py
+++ b/Lib/test/test_warnings.py
@@ -5,7 +5,7 @@ from io import StringIO
 import sys
 import unittest
 from test import support
-from test.script_helper import assert_python_ok
+from test.script_helper import assert_python_ok, assert_python_failure
 
 from test import warning_tests
 
@@ -432,6 +432,41 @@ class WarnTests(BaseTest):
         with self.assertRaises(ValueError):
             self.module.warn(BadStrWarning())
 
+    def test_warning_classes(self):
+        class MyWarningClass(Warning):
+            pass
+
+        class NonWarningSubclass:
+            pass
+
+        # passing a non-subclass of Warning should raise a TypeError
+        with self.assertRaises(TypeError) as cm:
+            self.module.warn('bad warning category', '')
+        self.assertIn('category must be a Warning subclass, not ',
+                      str(cm.exception))
+
+        with self.assertRaises(TypeError) as cm:
+            self.module.warn('bad warning category', NonWarningSubclass)
+        self.assertIn('category must be a Warning subclass, not ',
+                      str(cm.exception))
+
+        # check that warning instances also raise a TypeError
+        with self.assertRaises(TypeError) as cm:
+            self.module.warn('bad warning category', MyWarningClass())
+        self.assertIn('category must be a Warning subclass, not ',
+                      str(cm.exception))
+
+        with self.assertWarns(MyWarningClass) as cm:
+            self.module.warn('good warning category', MyWarningClass)
+        self.assertEqual('good warning category', str(cm.warning))
+
+        with self.assertWarns(UserWarning) as cm:
+            self.module.warn('good warning category', None)
+        self.assertEqual('good warning category', str(cm.warning))
+
+        with self.assertWarns(MyWarningClass) as cm:
+            self.module.warn('good warning category', MyWarningClass)
+        self.assertIsInstance(cm.warning, Warning)
 
 class CWarnTests(WarnTests, unittest.TestCase):
     module = c_warnings
@@ -821,7 +856,19 @@ class EnvironmentVariableTests(BaseTest):
             "import sys; sys.stdout.write(str(sys.warnoptions))",
             PYTHONWARNINGS="ignore::DeprecationWarning")
         self.assertEqual(stdout,
-            b"['ignore::UnicodeWarning', 'ignore::DeprecationWarning']")
+            b"['ignore::DeprecationWarning', 'ignore::UnicodeWarning']")
+
+    def test_conflicting_envvar_and_command_line(self):
+        rc, stdout, stderr = assert_python_failure("-Werror::DeprecationWarning", "-c",
+            "import sys, warnings; sys.stdout.write(str(sys.warnoptions)); "
+            "warnings.warn('Message', DeprecationWarning)",
+            PYTHONWARNINGS="default::DeprecationWarning")
+        self.assertEqual(stdout,
+            b"['default::DeprecationWarning', 'error::DeprecationWarning']")
+        self.assertEqual(stderr.splitlines(),
+            [b"Traceback (most recent call last):",
+             b"  File \"<string>\", line 1, in <module>",
+             b"DeprecationWarning: Message"])
 
     @unittest.skipUnless(sys.getfilesystemencoding() != 'ascii',
                          'requires non-ascii filesystemencoding')
diff --git a/Lib/test/test_weakref.py b/Lib/test/test_weakref.py
index 3e7347cf33..e735376a67 100644
--- a/Lib/test/test_weakref.py
+++ b/Lib/test/test_weakref.py
@@ -92,6 +92,18 @@ class ReferencesTestCase(TestBase):
         self.check_basic_callback(create_function)
         self.check_basic_callback(create_bound_method)
 
+    @support.cpython_only
+    def test_cfunction(self):
+        import _testcapi
+        create_cfunction = _testcapi.create_cfunction
+        f = create_cfunction()
+        wr = weakref.ref(f)
+        self.assertIs(wr(), f)
+        del f
+        self.assertIsNone(wr())
+        self.check_basic_ref(create_cfunction)
+        self.check_basic_callback(create_cfunction)
+
     def test_multiple_callbacks(self):
         o = C()
         ref1 = weakref.ref(o, self.callback)
@@ -1574,6 +1586,14 @@ class MappingTestCase(TestBase):
         self.assertEqual(len(d), 0)
         self.assertEqual(count, 2)
 
+    def test_make_weak_valued_dict_repr(self):
+        dict = weakref.WeakValueDictionary()
+        self.assertRegex(repr(dict), '<WeakValueDictionary at 0x.*>')
+
+    def test_make_weak_keyed_dict_repr(self):
+        dict = weakref.WeakKeyDictionary()
+        self.assertRegex(repr(dict), '<WeakKeyDictionary at 0x.*>')
+
 from test import mapping_tests
 
 class WeakValueDictionaryTestCase(mapping_tests.BasicTestMappingProtocol):
diff --git a/Lib/test/test_wsgiref.py b/Lib/test/test_wsgiref.py
index e213d778f1..479fcbc538 100644
--- a/Lib/test/test_wsgiref.py
+++ b/Lib/test/test_wsgiref.py
@@ -343,6 +343,7 @@ class HeaderTests(TestCase):
 
     def testMappingInterface(self):
         test = [('x','y')]
+        self.assertEqual(len(Headers()), 0)
         self.assertEqual(len(Headers([])),0)
         self.assertEqual(len(Headers(test[:])),1)
         self.assertEqual(Headers(test[:]).keys(), ['x'])
@@ -350,7 +351,7 @@ class HeaderTests(TestCase):
         self.assertEqual(Headers(test[:]).items(), test)
         self.assertIsNot(Headers(test).items(), test)  # must be copy!
 
-        h=Headers([])
+        h = Headers()
         del h['foo']   # should not raise an error
 
         h['Foo'] = 'bar'
@@ -375,9 +376,8 @@ class HeaderTests(TestCase):
     def testRequireList(self):
         self.assertRaises(TypeError, Headers, "foo")
 
-
     def testExtras(self):
-        h = Headers([])
+        h = Headers()
         self.assertEqual(str(h),'\r\n')
 
         h.add_header('foo','bar',baz="spam")
diff --git a/Lib/test/test_xml_etree_c.py b/Lib/test/test_xml_etree_c.py
index 816aa8645d..d0df38d3e6 100644
--- a/Lib/test/test_xml_etree_c.py
+++ b/Lib/test/test_xml_etree_c.py
@@ -55,7 +55,7 @@ class SizeofTest(unittest.TestCase):
     def setUp(self):
         self.elementsize = support.calcobjsize('5P')
         # extra
-        self.extra = struct.calcsize('PiiP4P')
+        self.extra = struct.calcsize('PnnP4P')
 
     check_sizeof = support.check_sizeof
 
diff --git a/Lib/test/test_xmlrpc.py b/Lib/test/test_xmlrpc.py
index 71b590cc59..dc37be2bf1 100644
--- a/Lib/test/test_xmlrpc.py
+++ b/Lib/test/test_xmlrpc.py
@@ -287,7 +287,7 @@ class DateTimeTestCase(unittest.TestCase):
     def test_repr(self):
         d = datetime.datetime(2007,1,2,3,4,5)
         t = xmlrpclib.DateTime(d)
-        val ="<DateTime '20070102T03:04:05' at %x>" % id(t)
+        val ="<DateTime '20070102T03:04:05' at %#x>" % id(t)
         self.assertEqual(repr(t), val)
 
     def test_decode(self):
@@ -713,6 +713,23 @@ class SimpleServerTestCase(BaseServerTestCase):
         conn.request('POST', '/RPC2 HTTP/1.0\r\nContent-Length: 100\r\n\r\nbye')
         conn.close()
 
+    def test_context_manager(self):
+        with xmlrpclib.ServerProxy(URL) as server:
+            server.add(2, 3)
+            self.assertNotEqual(server('transport')._connection,
+                                (None, None))
+        self.assertEqual(server('transport')._connection,
+                         (None, None))
+
+    def test_context_manager_method_error(self):
+        try:
+            with xmlrpclib.ServerProxy(URL) as server:
+                server.add(2, "a")
+        except xmlrpclib.Fault:
+            pass
+        self.assertEqual(server('transport')._connection,
+                         (None, None))
+
 
 class MultiPathServerTestCase(BaseServerTestCase):
     threadFunc = staticmethod(http_multi_server)
@@ -891,7 +908,7 @@ class GzipUtilTestCase(unittest.TestCase):
         data = b'\0' * (max_gzip_decode + 1)
         encoded = xmlrpclib.gzip_encode(data)
 
-        with self.assertRaisesRegexp(ValueError,
+        with self.assertRaisesRegex(ValueError,
                                      "max gzipped payload length exceeded"):
             xmlrpclib.gzip_decode(encoded)
 
@@ -919,6 +936,7 @@ class ServerProxyTestCase(unittest.TestCase):
         p = xmlrpclib.ServerProxy(self.url, transport=t)
         self.assertEqual(p('transport'), t)
 
+
 # This is a contrived way to make a failure occur on the server side
 # in order to test the _send_traceback_header flag on the server
 class FailingMessageClass(http.client.HTTPMessage):
diff --git a/Lib/test/test_zipfile.py b/Lib/test/test_zipfile.py
index 3d8f9bc9c7..f458f303dd 100644
--- a/Lib/test/test_zipfile.py
+++ b/Lib/test/test_zipfile.py
@@ -330,6 +330,37 @@ class AbstractTestsWithSourceFile:
                     while zipopen.read1(100):
                         pass
 
+    def test_repr(self):
+        fname = 'file.name'
+        for f in get_files(self):
+            with zipfile.ZipFile(f, 'w', self.compression) as zipfp:
+                zipfp.write(TESTFN, fname)
+                r = repr(zipfp)
+                self.assertIn("mode='w'", r)
+
+            with zipfile.ZipFile(f, 'r') as zipfp:
+                r = repr(zipfp)
+                if isinstance(f, str):
+                    self.assertIn('filename=%r' % f, r)
+                else:
+                    self.assertIn('file=%r' % f, r)
+                self.assertIn("mode='r'", r)
+                r = repr(zipfp.getinfo(fname))
+                self.assertIn('filename=%r' % fname, r)
+                self.assertIn('filemode=', r)
+                self.assertIn('file_size=', r)
+                if self.compression != zipfile.ZIP_STORED:
+                    self.assertIn('compress_type=', r)
+                    self.assertIn('compress_size=', r)
+                with zipfp.open(fname) as zipopen:
+                    r = repr(zipopen)
+                    self.assertIn('name=%r' % fname, r)
+                    self.assertIn("mode='r'", r)
+                    if self.compression != zipfile.ZIP_STORED:
+                        self.assertIn('compress_type=', r)
+                self.assertIn('[closed]', repr(zipopen))
+            self.assertIn('[closed]', repr(zipfp))
+
     def tearDown(self):
         unlink(TESTFN)
         unlink(TESTFN2)
@@ -1647,6 +1678,34 @@ class LzmaTestsWithRandomBinaryFiles(AbstractTestsWithRandomBinaryFiles,
     compression = zipfile.ZIP_LZMA
 
 
+# Privide the tell() method but not seek()
+class Tellable:
+    def __init__(self, fp):
+        self.fp = fp
+        self.offset = 0
+
+    def write(self, data):
+        self.offset += self.fp.write(data)
+
+    def tell(self):
+        return self.offset
+
+    def flush(self):
+        pass
+
+class UnseekableTests(unittest.TestCase):
+    def test_writestr_tellable(self):
+        f = io.BytesIO()
+        with zipfile.ZipFile(Tellable(f), 'w', zipfile.ZIP_STORED) as zipfp:
+            zipfp.writestr('ones', b'111')
+            zipfp.writestr('twos', b'222')
+        with zipfile.ZipFile(f, mode='r') as zipf:
+            with zipf.open('ones') as zopen:
+                self.assertEqual(zopen.read(), b'111')
+            with zipf.open('twos') as zopen:
+                self.assertEqual(zopen.read(), b'222')
+
+
 @requires_zlib
 class TestsWithMultipleOpens(unittest.TestCase):
     @classmethod
@@ -1663,35 +1722,52 @@ class TestsWithMultipleOpens(unittest.TestCase):
     def test_same_file(self):
         # Verify that (when the ZipFile is in control of creating file objects)
         # multiple open() calls can be made without interfering with each other.
-        self.make_test_archive(TESTFN2)
-        with zipfile.ZipFile(TESTFN2, mode="r") as zipf:
-            with zipf.open('ones') as zopen1, zipf.open('ones') as zopen2:
-                data1 = zopen1.read(500)
-                data2 = zopen2.read(500)
-                data1 += zopen1.read()
-                data2 += zopen2.read()
-            self.assertEqual(data1, data2)
-            self.assertEqual(data1, self.data1)
+        for f in get_files(self):
+            self.make_test_archive(f)
+            with zipfile.ZipFile(f, mode="r") as zipf:
+                with zipf.open('ones') as zopen1, zipf.open('ones') as zopen2:
+                    data1 = zopen1.read(500)
+                    data2 = zopen2.read(500)
+                    data1 += zopen1.read()
+                    data2 += zopen2.read()
+                self.assertEqual(data1, data2)
+                self.assertEqual(data1, self.data1)
 
     def test_different_file(self):
         # Verify that (when the ZipFile is in control of creating file objects)
         # multiple open() calls can be made without interfering with each other.
-        self.make_test_archive(TESTFN2)
-        with zipfile.ZipFile(TESTFN2, mode="r") as zipf:
-            with zipf.open('ones') as zopen1, zipf.open('twos') as zopen2:
-                data1 = zopen1.read(500)
-                data2 = zopen2.read(500)
-                data1 += zopen1.read()
-                data2 += zopen2.read()
-            self.assertEqual(data1, self.data1)
-            self.assertEqual(data2, self.data2)
+        for f in get_files(self):
+            self.make_test_archive(f)
+            with zipfile.ZipFile(f, mode="r") as zipf:
+                with zipf.open('ones') as zopen1, zipf.open('twos') as zopen2:
+                    data1 = zopen1.read(500)
+                    data2 = zopen2.read(500)
+                    data1 += zopen1.read()
+                    data2 += zopen2.read()
+                self.assertEqual(data1, self.data1)
+                self.assertEqual(data2, self.data2)
 
     def test_interleaved(self):
         # Verify that (when the ZipFile is in control of creating file objects)
         # multiple open() calls can be made without interfering with each other.
-        self.make_test_archive(TESTFN2)
-        with zipfile.ZipFile(TESTFN2, mode="r") as zipf:
-            with zipf.open('ones') as zopen1, zipf.open('twos') as zopen2:
+        for f in get_files(self):
+            self.make_test_archive(f)
+            with zipfile.ZipFile(f, mode="r") as zipf:
+                with zipf.open('ones') as zopen1, zipf.open('twos') as zopen2:
+                    data1 = zopen1.read(500)
+                    data2 = zopen2.read(500)
+                    data1 += zopen1.read()
+                    data2 += zopen2.read()
+                self.assertEqual(data1, self.data1)
+                self.assertEqual(data2, self.data2)
+
+    def test_read_after_close(self):
+        for f in get_files(self):
+            self.make_test_archive(f)
+            with contextlib.ExitStack() as stack:
+                with zipfile.ZipFile(f, 'r') as zipf:
+                    zopen1 = stack.enter_context(zipf.open('ones'))
+                    zopen2 = stack.enter_context(zipf.open('twos'))
                 data1 = zopen1.read(500)
                 data2 = zopen2.read(500)
                 data1 += zopen1.read()
@@ -1699,43 +1775,32 @@ class TestsWithMultipleOpens(unittest.TestCase):
             self.assertEqual(data1, self.data1)
             self.assertEqual(data2, self.data2)
 
-    def test_read_after_close(self):
-        self.make_test_archive(TESTFN2)
-        with contextlib.ExitStack() as stack:
-            with zipfile.ZipFile(TESTFN2, 'r') as zipf:
-                zopen1 = stack.enter_context(zipf.open('ones'))
-                zopen2 = stack.enter_context(zipf.open('twos'))
-            data1 = zopen1.read(500)
-            data2 = zopen2.read(500)
-            data1 += zopen1.read()
-            data2 += zopen2.read()
-        self.assertEqual(data1, self.data1)
-        self.assertEqual(data2, self.data2)
-
     def test_read_after_write(self):
-        with zipfile.ZipFile(TESTFN2, 'w', zipfile.ZIP_DEFLATED) as zipf:
-            zipf.writestr('ones', self.data1)
-            zipf.writestr('twos', self.data2)
-            with zipf.open('ones') as zopen1:
-                data1 = zopen1.read(500)
-        self.assertEqual(data1, self.data1[:500])
-        with zipfile.ZipFile(TESTFN2, 'r') as zipf:
-            data1 = zipf.read('ones')
-            data2 = zipf.read('twos')
-        self.assertEqual(data1, self.data1)
-        self.assertEqual(data2, self.data2)
+        for f in get_files(self):
+            with zipfile.ZipFile(f, 'w', zipfile.ZIP_DEFLATED) as zipf:
+                zipf.writestr('ones', self.data1)
+                zipf.writestr('twos', self.data2)
+                with zipf.open('ones') as zopen1:
+                    data1 = zopen1.read(500)
+            self.assertEqual(data1, self.data1[:500])
+            with zipfile.ZipFile(f, 'r') as zipf:
+                data1 = zipf.read('ones')
+                data2 = zipf.read('twos')
+            self.assertEqual(data1, self.data1)
+            self.assertEqual(data2, self.data2)
 
     def test_write_after_read(self):
-        with zipfile.ZipFile(TESTFN2, "w", zipfile.ZIP_DEFLATED) as zipf:
-            zipf.writestr('ones', self.data1)
-            with zipf.open('ones') as zopen1:
-                zopen1.read(500)
-                zipf.writestr('twos', self.data2)
-        with zipfile.ZipFile(TESTFN2, 'r') as zipf:
-            data1 = zipf.read('ones')
-            data2 = zipf.read('twos')
-        self.assertEqual(data1, self.data1)
-        self.assertEqual(data2, self.data2)
+        for f in get_files(self):
+            with zipfile.ZipFile(f, "w", zipfile.ZIP_DEFLATED) as zipf:
+                zipf.writestr('ones', self.data1)
+                with zipf.open('ones') as zopen1:
+                    zopen1.read(500)
+                    zipf.writestr('twos', self.data2)
+            with zipfile.ZipFile(f, 'r') as zipf:
+                data1 = zipf.read('ones')
+                data2 = zipf.read('twos')
+            self.assertEqual(data1, self.data1)
+            self.assertEqual(data2, self.data2)
 
     def test_many_opens(self):
         # Verify that read() and open() promptly close the file descriptor,
diff --git a/Lib/test/test_zipimport_support.py b/Lib/test/test_zipimport_support.py
index 66c35578e2..2e801a8119 100644
--- a/Lib/test/test_zipimport_support.py
+++ b/Lib/test/test_zipimport_support.py
@@ -39,7 +39,7 @@ def _run_object_doctest(obj, module):
     # Use the object's fully qualified name if it has one
     # Otherwise, use the module's name
     try:
-        name = "%s.%s" % (obj.__module__, obj.__name__)
+        name = "%s.%s" % (obj.__module__, obj.__qualname__)
     except AttributeError:
         name = module.__name__
     for example in finder.find(obj, name, module):