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

1 files changed, 18 insertions, 0 deletions

diff --git a/Lib/test/test_types.py b/Lib/test/test_types.py
index 382ca03e5a..4a9fcba526 100644
--- a/Lib/test/test_types.py
+++ b/Lib/test/test_types.py
@@ -576,6 +576,24 @@ class TypesTests(unittest.TestCase):
         self.assertGreater(object.__basicsize__, 0)
         self.assertGreater(tuple.__itemsize__, 0)
 
+    def test_slot_wrapper_types(self):
+        self.assertIsInstance(object.__init__, types.SlotWrapperType)
+        self.assertIsInstance(object.__str__, types.SlotWrapperType)
+        self.assertIsInstance(object.__lt__, types.SlotWrapperType)
+        self.assertIsInstance(int.__lt__, types.SlotWrapperType)
+
+    def test_method_wrapper_types(self):
+        self.assertIsInstance(object().__init__, types.MethodWrapperType)
+        self.assertIsInstance(object().__str__, types.MethodWrapperType)
+        self.assertIsInstance(object().__lt__, types.MethodWrapperType)
+        self.assertIsInstance((42).__lt__, types.MethodWrapperType)
+
+    def test_method_descriptor_types(self):
+        self.assertIsInstance(str.join, types.MethodDescriptorType)
+        self.assertIsInstance(list.append, types.MethodDescriptorType)
+        self.assertIsInstance(''.join, types.BuiltinMethodType)
+        self.assertIsInstance([].append, types.BuiltinMethodType)
+
 
 class MappingProxyTests(unittest.TestCase):
     mappingproxy = types.MappingProxyType