bpo-36379: __ipow__ must be a ternaryfunc, not a binaryfunc (GH-13546)

If a type's __ipow__ method was implemented in C, attempting to use
the *modulo* parameter would cause crashes.


https://bugs.python.org/issue36379

1 files changed, 7 insertions, 0 deletions

diff --git a/Lib/test/test_capi.py b/Lib/test/test_capi.py
index 795aa78..4dd78bb 100644
--- a/Lib/test/test_capi.py
+++ b/Lib/test/test_capi.py
@@ -184,6 +184,13 @@ class CAPITest(unittest.TestCase):
         o @= m1
         self.assertEqual(o, ("matmul", 42, m1))
 
+    def test_c_type_with_ipow(self):
+        # When the __ipow__ method of a type was implemented in C, using the
+        # modulo param would cause segfaults.
+        o = _testcapi.ipowType()
+        self.assertEqual(o.__ipow__(1), (1, None))
+        self.assertEqual(o.__ipow__(2, 2), (2, 2))
+
     def test_return_null_without_error(self):
         # Issue #23571: A function must not return NULL without setting an
         # error