Alexey Izbyshev <izbys...@ispras.ru> added the comment: I've also checked that ABC.register() doesn't allow non-classes (and PEP 3119 mentions that).
Looking at PyObject_IsSubclass in Objects/abstract.c, the only case in which its check_class() could be avoided is if there is a custom __subclasscheck__: >>> class M(type): ... def __subclasscheck__(cls, c): ... return c == 1 or super().__subclasscheck__(c) ... >>> class A(metaclass=M): ... pass ... >>> issubclass(1, A) True If there is no need to support such weird __subclasscheck__, check_class() could be called earlier. Note, however, that check_class() treats anything having __bases__ as a class, so moving the check alone is not enough to avoid the crash in all cases. ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue32999> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
