Merge 3.5

Issue #21925: warnings.formatwarning() now catches exceptions when calling
linecache.getline() and tracemalloc.get_object_traceback() to be able to log
ResourceWarning emitted late during the Python shutdown process.

1 files changed, 26 insertions, 6 deletions

diff --git a/Lib/test/test_warnings/__init__.py b/Lib/test/test_warnings/__init__.py
index e6f47cda4c..9f1cd7574f 100644
--- a/Lib/test/test_warnings/__init__.py
+++ b/Lib/test/test_warnings/__init__.py
@@ -536,6 +536,14 @@ class WCmdLineTests(BaseTest):
             self.module._setoption('error::Warning::0')
             self.assertRaises(UserWarning, self.module.warn, 'convert to error')
 
+
+class CWCmdLineTests(WCmdLineTests, unittest.TestCase):
+    module = c_warnings
+
+
+class PyWCmdLineTests(WCmdLineTests, unittest.TestCase):
+    module = py_warnings
+
     def test_improper_option(self):
         # Same as above, but check that the message is printed out when
         # the interpreter is executed. This also checks that options are
@@ -552,12 +560,6 @@ class WCmdLineTests(BaseTest):
         self.assertFalse(out.strip())
         self.assertNotIn(b'RuntimeWarning', err)
 
-class CWCmdLineTests(WCmdLineTests, unittest.TestCase):
-    module = c_warnings
-
-class PyWCmdLineTests(WCmdLineTests, unittest.TestCase):
-    module = py_warnings
-
 
 class _WarningsTests(BaseTest, unittest.TestCase):
 
@@ -976,6 +978,7 @@ class BootstrapTest(unittest.TestCase):
             # Use -W to load warnings module at startup
             assert_python_ok('-c', 'pass', '-W', 'always', PYTHONPATH=cwd)
 
+
 class FinalizationTest(unittest.TestCase):
     def test_finalization(self):
         # Issue #19421: warnings.warn() should not crash
@@ -995,6 +998,23 @@ a=A()
         # of the script
         self.assertEqual(err, b'__main__:7: UserWarning: test')
 
+    def test_late_resource_warning(self):
+        # Issue #21925: Emitting a ResourceWarning late during the Python
+        # shutdown must be logged.
+
+        expected = b"sys:1: ResourceWarning: unclosed file "
+
+        # don't import the warnings module
+        # (_warnings will try to import it)
+        code = "f = open(%a)" % __file__
+        rc, out, err = assert_python_ok("-c", code)
+        self.assertTrue(err.startswith(expected), ascii(err))
+
+        # import the warnings module
+        code = "import warnings; f = open(%a)" % __file__
+        rc, out, err = assert_python_ok("-c", code)
+        self.assertTrue(err.startswith(expected), ascii(err))
+
 
 def setUpModule():
     py_warnings.onceregistry.clear()