Does this affect when the limited API is used?
(When Vim is compiled with the limited API, it should work both with Python 3.13 and Python 3.12 or earlier.)

PyObject_CallFunction is listed as part of the Limited API according to https://docs.python.org/3/c-api/stable.html#contents-of-limited-api but perhaps I didn't understand your question.

Hi @k-takata ,

what do you mean by "VIm compiled with limited API" - do you mean "dynamic" configure option value for --enable-python3interp? If you do, I would say the patch preserves using the old API for older Pythons and uses the new one for 3.13.
Please let us know how we could change the patch - VIm is currently not building in Fedora Rawhide, because new Python 3.13 came into the compose, so we would like to help with the fix.

@zdohnal I meant the --with-python3-stable-abi option. (Limited API == Stable ABI)
Ideally, if Vim is compiled with --enable-python3interp=dynamic --with-python3-stable-abi=3.8, it should work with any version of Python between 3.8 and 3.13.
This is mostly useful for Windows users, so we can include this PR for now, and can check the compatibility later (if it is difficult to check).

@k-takata the current Fedora releases have Python 3.12 and Centos Stream 9 has 3.9 - I've successfully built the current Vim on all mentioned platforms with the options you mentioned. Tried ':py3 print('hello')' in c9s and it worked. In Fedora, public tests which run Vim project test suite passed with the patch, so it looks good.

Thanks all.