Skip to content

bpo-44232: Fix type_new crash caused by AssertionError #26358

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
Fidget-Spinner wants to merge 1 commit into from
Closed

bpo-44232: Fix type_new crash caused by AssertionError #26358

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
17 changes: 16 additions & 1 deletion Lib/test/test_builtin.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -19,7 +19,7 @@
import types
import unittest
import warnings
from contextlib import ExitStack
from contextlib import ExitStack, suppress
from functools import partial
from inspect import CO_COROUTINE
from itertools import product
Expand Down Expand Up @@ -2343,6 +2343,21 @@ def test_namespace_order(self):
C = type('C', (), od)
self.assertEqual(list(C.__dict__.items())[:2], [('b', 2), ('a', 1)])

def test_new_type_bad_tp_new(self):
# bpo-44232: Bad tp_new in bases tuple should just return NULL
# instead of causing an interpreter crash in debug mode.
class XBase(type):
def __new__(cls, name, bases, attrs, **kwargs):
attrs.pop('__module__')
return super().__new__(cls, name, bases, attrs, **kwargs)

class X(metaclass=XBase): ...

# The actual error here doesn't matter. As long as the interpreter
# doesn't crash.
with suppress(Exception):
type('A', (X,), {})


def load_tests(loader, tests, pattern):
from doctest import DocTestSuite
Expand Down
2 changes: 2 additions & 0 deletions Misc/NEWS.d/next/Core and Builtins/2021-05-25-23-55-02.bpo-44232.KEDM_e.rst
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,2 @@
Fixed a crash caused by bad metaclass bases being passed into :func:`type`.
This only affected debug builds of Python -- release builds are unaffected.
1 change: 0 additions & 1 deletion Objects/typeobject.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -3310,7 +3310,6 @@ type_new(PyTypeObject *metatype, PyObject *args, PyObject *kwds)
return NULL;
}
if (res == 1) {
assert(type != NULL);
return type;
}
assert(ctx.base != NULL);
Expand Down