array iterator segfault on __setstate__() when exhausted

[tom-pytel]

Crash report

What happened?

>>> import array
... a = array.array('i')
... it = iter(a)
... list(it)
... it.__setstate__(0)
... 
Segmentation fault (core dumped)

This goes back at least to py 3.8 (checked on that one), PR fix incoming.

CPython versions tested on:

3.14

Operating systems tested on:

Linux

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

Python 3.14.0a4+ (heads/arrayiter:7d97bc8eda, Jan 17 2025, 16:24:27) [GCC 11.4.0]

Linked PRs

• gh-128961: Fix exhausted array iterator crash in __setstate__ #128962
• [3.13] gh-128961: Fix exhausted array iterator crash in __setstate__() (GH-128962) #128976
• [3.12] gh-128961: Fix exhausted array iterator crash in __setstate__() (GH-128962) #128977

[tom-pytel]

Ping @erlend-aasland

[erlend-aasland]

Fixed with:

• gh-128961: Fix exhausted array iterator crash in __setstate__ #128962
• [3.13] gh-128961: Fix exhausted array iterator crash in __setstate__() (GH-128962) #128976
• [3.12] gh-128961: Fix exhausted array iterator crash in __setstate__() (GH-128962) #128977

Auto-merge enabled for the backports. Closing as resolved. Thanks for identifying the bug and fixing it, Tomasz!

[erlend-aasland]

For the record: this was discovered while the OP was working on #128943.