BugFix #14329

[Wintreist]

Closes #14329

Fixed the issue of getting the really closest label to the test. I abolished the priority of base classes over labels, but supported getting the usefixtures mark in reverse order (i.e. from the base class to the heir), since this is a unique case when you really need to call fixtures sequentially from the base class.

I did not add myself to the Authors, as I do not plan to be a pytest developer yet, I fixed the problem, as it interferes with my main project. Thanks

[bluetech]

Thanks, the changes LGTM. I pushed a few tweaks.

I'll let others a few days to review, then merge.

[RonnyPfannschmidt]

Under strict pedantic this is a breaking change
Im a bit torn for the classification

[bluetech]

Under strict pedantic every bug fix is a breaking change 😀

I think this case is sensible for a minor release. I don't actually expect the MRO thing to come up that much...

[bluetech]

Maybe the usefixtures change could be a bit more disruptive, but it will be annoying to separate the two...

[RonnyPfannschmidt]

The order of items changes slightly

That likes to break things

[bluetech]

The order of items changes slightly

What items are you referring to here? The mark list items, or the Items (tests) order changing due to usefixture changes?

That likes to break things

Would you prefer to defer this PR to pytest 10?