bpo-37619: update_one_slot() should not ignore wrapper descriptors for wrong type (GH-14836)

1 files changed, 12 insertions, 0 deletions

diff --git a/Lib/test/test_descr.py b/Lib/test/test_descr.py
index 4368bb585f..796e60a770 100644
--- a/Lib/test/test_descr.py
+++ b/Lib/test/test_descr.py
@@ -4649,6 +4649,18 @@ order (MRO) for bases """
         self.assertEqual(x["y"], 42)
         self.assertEqual(x, -x)
 
+    def test_wrong_class_slot_wrapper(self):
+        # Check bpo-37619: a wrapper descriptor taken from the wrong class
+        # should raise an exception instead of silently being ignored
+        class A(int):
+            __eq__ = str.__eq__
+            __add__ = str.__add__
+        a = A()
+        with self.assertRaises(TypeError):
+            a == a
+        with self.assertRaises(TypeError):
+            a + a
+
     def test_slot_shadows_class_variable(self):
         with self.assertRaises(ValueError) as cm:
             class X: