diff options
| -rw-r--r-- | Lib/test/test_typing.py | 16 | ||||
| -rw-r--r-- | Misc/NEWS.d/next/Library/2023-04-08-12-43-52.gh-issue-101162.yOCd_J.rst | 2 | ||||
| -rw-r--r-- | Objects/abstract.c | 2 | ||||
| -rw-r--r-- | Objects/genericaliasobject.c | 1 |
4 files changed, 20 insertions, 1 deletions
diff --git a/Lib/test/test_typing.py b/Lib/test/test_typing.py index 0450a87577e..fa39c796197 100644 --- a/Lib/test/test_typing.py +++ b/Lib/test/test_typing.py @@ -4091,6 +4091,22 @@ class GenericTests(BaseTestCase): with self.assertRaises(TypeError): C[()] + def test_generic_subclass_checks(self): + for typ in [list[int], List[int], + tuple[int, str], Tuple[int, str], + typing.Callable[..., None], + collections.abc.Callable[..., None]]: + with self.subTest(typ=typ): + self.assertRaises(TypeError, issubclass, typ, object) + self.assertRaises(TypeError, issubclass, typ, type) + self.assertRaises(TypeError, issubclass, typ, typ) + self.assertRaises(TypeError, issubclass, object, typ) + + # isinstance is fine: + self.assertTrue(isinstance(typ, object)) + # but, not when the right arg is also a generic: + self.assertRaises(TypeError, isinstance, typ, typ) + def test_init(self): T = TypeVar('T') S = TypeVar('S') diff --git a/Misc/NEWS.d/next/Library/2023-04-08-12-43-52.gh-issue-101162.yOCd_J.rst b/Misc/NEWS.d/next/Library/2023-04-08-12-43-52.gh-issue-101162.yOCd_J.rst new file mode 100644 index 00000000000..e9fadc8f436 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2023-04-08-12-43-52.gh-issue-101162.yOCd_J.rst @@ -0,0 +1,2 @@ +Forbid using :func:`builtins.issubclass` with :class:`types.GenericAlias` as +the first argument. diff --git a/Objects/abstract.c b/Objects/abstract.c index b4edcec6007..c113364a88a 100644 --- a/Objects/abstract.c +++ b/Objects/abstract.c @@ -2812,7 +2812,7 @@ object_issubclass(PyThreadState *tstate, PyObject *derived, PyObject *cls) return -1; } - /* Probably never reached anymore. */ + /* Can be reached when infinite recursion happens. */ return recursive_issubclass(derived, cls); } diff --git a/Objects/genericaliasobject.c b/Objects/genericaliasobject.c index df8873454ae..faf517b66b9 100644 --- a/Objects/genericaliasobject.c +++ b/Objects/genericaliasobject.c @@ -626,6 +626,7 @@ ga_vectorcall(PyObject *self, PyObject *const *args, static const char* const attr_exceptions[] = { "__class__", + "__bases__", "__origin__", "__args__", "__unpacked__", |