Failed assertion in typeobject.c::wrap_buffer for `b"".__buffer__(-2**31 - 1)`

[devdanzin]

Crash report

What happened?

Calling bytes_object.__buffer__(large_negative_number) in a debug build aborts with this message:

>>> b"".__buffer__(-2**31 - 1)
python: Objects/typeobject.c:9321: wrap_buffer: Assertion `_Py_STATIC_CAST(Py_ssize_t, _Py_STATIC_CAST(int, (flags))) == (flags)' failed.
Aborted

Found using fusil by @vstinner.

CPython versions tested on:

CPython main branch

Operating systems tested on:

Linux, Windows

Output from running 'python -VV' on the command line:

Python 3.14.0a1+ (heads/main:4ea214ea982, Nov 6 2024, 00:52:15) [MSC v.1941 64 bit (AMD64)]

Linked PRs

• gh-126594: Fix typeobject.c wrap_buffer() cast #126754
• [3.13] gh-126594: Fix typeobject.c wrap_buffer() cast (GH-126754) #127004
• [3.12] gh-126594: Fix typeobject.c wrap_buffer() cast (GH-126754) #127005

[vstinner]

I wrote PR gh-126754 to fix the issue.