Fix incorrect discovery of non-test __init__.py files.

[asottile]

Resolves #6194

[blueyed]

Simpler patch:

This fixes the regression:
```diff
@ src/_pytest/python.py:643 @ def isinitpath(self, path):
         return path in self.session._initialpaths

     def collect(self):
-        self._mount_obj_if_needed()
         this_path = self.fspath.dirpath()
         init_module = this_path.join("__init__.py")
         if init_module.check(file=1) and path_matches_patterns(
             init_module, self.config.getini("python_files")
         ):
+            self._mount_obj_if_needed()
             yield Module(init_module, self)
         pkg_prefixes = set()
         for path in this_path.visit(rec=self._recurse, bf=True, sort=True):

[blueyed]

When reverting (which I am not opposed to, I think it's rather a feature not a bugfix in the first place), it should have a changelog for that.

[nicoddemus]

If @blueyed's patch fixes the regression, we probably should go with that instead (perhaps makes sense to open a separate PR?).

Can somebody prepare a release then? I won't be on my computer later.

[asottile]

I can do it, I'll rebase that into this

[asottile]

When reverting (which I am not opposed to, I think it's rather a feature not a bugfix in the first place), it should have a changelog for that.

A revert of a bugfix which causes a regression is not a feature -- there is a changelog for the bugfix though

[blueyed]

A revert of a bugfix which causes a regression is not a feature

Never said that - I've meant the original bugfix was more like a feature.

there is a changelog for the bugfix though

Cool, but in case you had kept the revert this would have needed a changelog entry from what I can tell. That's what I've said.

[asottile]

ok, that patch "fixes" the tests I added but breaks the feature in the original patch -- I'm going to go back to fully reverting in spirit of getting this fix out

[asottile]

ok, we're back to revert + new tests now 🎉

[blueyed]

This fixes the test:

diff --git c/testing/test_skipping.py i/testing/test_skipping.py
index 371c3a4db..37b38b59c 100644
--- c/testing/test_skipping.py
+++ i/testing/test_skipping.py
@@ -1174,7 +1174,6 @@ def test_skip_package(testdir):

     testdir.makepyfile(
         """
-        import pytest
         def test_skip1():
             assert 0
         def test_skip2():
@@ -1182,6 +1181,6 @@ def test_skip2():
     """
     )

-    result = testdir.inline_run()
+    result = testdir.inline_run("-o", "python_files=*.py")
     _, skipped, _ = result.listoutcomes()
     assert len(skipped) == 2

I'm not sure, but in general python_files needs to include __init__.py for them / packages to be cosidered.
/cc @zefirior

[asottile]

I'd rather revert at this point

[blueyed]

I'm not opposed to it still. Please merge master into features then though afterwards.

[asottile]

of course, that's part of releasing after all :)

[asottile]

could someone review this patch or should I just take it out?

[blueyed]

Let's wait for @nicoddemus or @RonnyPfannschmidt - since I think the initial test might be wrong I am not approving it myself (but also not blocking it of course).

[blueyed]

Can you create the PR for merging master into features then, please?

[asottile]

yep, my computer was rebooting