Issue #22995: Instances of extension types with a state that aren't

subclasses of list or dict and haven't implemented any pickle-related
methods (__reduce__, __reduce_ex__, __getnewargs__, __getnewargs_ex__,
or __getstate__), can no longer be pickled.  Including memoryview.

1 files changed, 13 insertions, 0 deletions

diff --git a/Lib/test/test_csv.py b/Lib/test/test_csv.py
index 4763bbbfb7..921fd4a75f 100644
--- a/Lib/test/test_csv.py
+++ b/Lib/test/test_csv.py
@@ -1,6 +1,7 @@
 # Copyright (C) 2001,2002 Python Software Foundation
 # csv package unit tests
 
+import copy
 import io
 import sys
 import os
@@ -9,6 +10,7 @@ from io import StringIO
 from tempfile import TemporaryFile
 import csv
 import gc
+import pickle
 from test import support
 
 class Test_Csv(unittest.TestCase):
@@ -424,6 +426,17 @@ class TestDialectRegistry(unittest.TestCase):
         self.assertRaises(TypeError, csv.reader, [], quoting = -1)
         self.assertRaises(TypeError, csv.reader, [], quoting = 100)
 
+    def test_copy(self):
+        for name in csv.list_dialects():
+            dialect = csv.get_dialect(name)
+            self.assertRaises(TypeError, copy.copy, dialect)
+
+    def test_pickle(self):
+        for name in csv.list_dialects():
+            dialect = csv.get_dialect(name)
+            for proto in range(pickle.HIGHEST_PROTOCOL + 1):
+                self.assertRaises(TypeError, pickle.dumps, dialect, proto)
+
 class TestCsvBase(unittest.TestCase):
     def readerAssertEqual(self, input, expected_result):
         with TemporaryFile("w+", newline='') as fileobj: