Issue #29392: Prevent crash when passing invalid arguments into msvcrt module.

1 files changed, 13 insertions, 0 deletions

diff --git a/Lib/unittest/test/testmock/testsentinel.py b/Lib/unittest/test/testmock/testsentinel.py
index 3fb5acbc25..de53509803 100644
--- a/Lib/unittest/test/testmock/testsentinel.py
+++ b/Lib/unittest/test/testmock/testsentinel.py
@@ -1,4 +1,6 @@
 import unittest
+import copy
+import pickle
 from unittest.mock import sentinel, DEFAULT
 
 
@@ -23,6 +25,17 @@ class SentinelTest(unittest.TestCase):
         # If this doesn't raise an AttributeError then help(mock) is broken
         self.assertRaises(AttributeError, lambda: sentinel.__bases__)
 
+    def testPickle(self):
+        for proto in range(pickle.HIGHEST_PROTOCOL+1):
+            with self.subTest(protocol=proto):
+                pickled = pickle.dumps(sentinel.whatever, proto)
+                unpickled = pickle.loads(pickled)
+                self.assertIs(unpickled, sentinel.whatever)
+
+    def testCopy(self):
+        self.assertIs(copy.copy(sentinel.whatever), sentinel.whatever)
+        self.assertIs(copy.deepcopy(sentinel.whatever), sentinel.whatever)
+
 
 if __name__ == '__main__':
     unittest.main()