1 files changed, 21 insertions, 0 deletions
diff --git a/Lib/ctypes/test/test_parameters.py b/Lib/ctypes/test/test_parameters.py
index 4eaa15a..e4c25fd 100644
--- a/Lib/ctypes/test/test_parameters.py
+++ b/Lib/ctypes/test/test_parameters.py
@@ -1,5 +1,6 @@
 import unittest
 from ctypes.test import need_symbol
+import test.support
 
 class SimpleTypesTestCase(unittest.TestCase):
 
@@ -180,6 +181,26 @@ class SimpleTypesTestCase(unittest.TestCase):
         self.assertRaises(TypeError, _Pointer.from_param, 42)
         self.assertRaises(TypeError, _SimpleCData.from_param, 42)
 
+    @test.support.cpython_only
+    def test_issue31311(self):
+        # __setstate__ should neither raise a SystemError nor crash in case
+        # of a bad __dict__.
+        from ctypes import Structure
+
+        class BadStruct(Structure):
+            @property
+            def __dict__(self):
+                pass
+        with self.assertRaises(TypeError):
+            BadStruct().__setstate__({}, b'foo')
+
+        class WorseStruct(Structure):
+            @property
+            def __dict__(self):
+                1/0
+        with self.assertRaises(ZeroDivisionError):
+            WorseStruct().__setstate__({}, b'foo')
+
 ################################################################
 
 if __name__ == '__main__':