3.11 regression: default arguments in PyEval_EvalCodeEx

[MatthieuDartiailh]

Bug report

3.11 Started using _PyFunction_FromConstructor inside PyEval_EvalCodeEx. #92173 reported that this caused issues when closures were involved because _PyFunction_FromConstructor discarded the closure found in PyFrameConstructor. This was fixed in #92175.

It turns out the same holds true for default arguments and default kw arguments as can be seen at https://github.com/python/cpython/blob/main/Objects/funcobject.c#L90-L91 and is a regression compared to 3.10.

The fix appears fairly simple but I would love to have some guidance as to where to add a test for it.

Your environment

• CPython versions tested on: 3.11.0
• Operating system and architecture: Windows x86-64

Linked PRs

• gh-101072: support default and kw default in PyEval_EvalCodeEx for 3.11+ #101127
• [3.11] gh-101072: support default and kw default in PyEval_EvalCodeEx for 3.11+ (GH-101127) #101636

[MatthieuDartiailh]

@larryhastings This may be of interest since you authored #92175

[carljm]

The only usage of PyEval_EvalCodeEx within CPython is via builtin exec, which would never use these fields.

So the only context in which the regression matters is external use of PyEval_EvalCodeEx as part of the C API. So I suggest the test should go into test_capi.py (probably requiring a custom C test function in Modules/_testcapimodule.c).

EDIT: just realized you already have a PR and reached the same conclusion :)

[MatthieuDartiailh]

This can now be closed I believe.