pathlib.PureWindowsPath.match() mishandles path anchors

[barneygale]

pathlib.PurePath.match() doesn't use fnmatch() to match path anchors, contrary to the documentation. Instead, it considers the drive and root of the pattern separately; if either (or both) is specified in the pattern, it must exactly match the corresponding drive/root in the path.

This results in the following:

>>> from pathlib import PureWindowsPath as P
>>> P('c:/b.py').match('*:/*.py')
False
>>> P('c:/b.py').match('c:*.py')
True
>>> P('c:/b.py').match('/*.py')
True
>>> P('//some/share/a.py').match('//*/*/*.py')
False
>>> P('//some/share/a.py').match('/*.py')
True

All of these results are wrong IMO.

Linked PRs

• gh-101360: Fix anchor matching in pathlib.PureWindowsPath.match() #101363

[barneygale]

I think I know why this behaviour is here: pathlib originally wouldn't parse patterns like *:/ because it required drive letters to be alphabetic. match() worked around this by treating empty drives like *.

The alphabetic drive requirement was removed in 2ba0fd5 (3.12).

[barneygale]

Fixed in #101363 / d401b20