`Distribution.files` does not show files with absolute RECORD entries on Windows with Python 3.10 and 3.11

[radoering]

If an installed distribution contains absolute paths in the RECORD file, Distribution.files is missing these files. (installer writes absolute paths for executable scripts on Windows since pypa/installer#286.)

To reproduce:

Build a sample project with an executable script

project structure:

sampleproject/
├── sample/
│   ├── __init__.py
│   └── __main__.py
└── pyproject.toml

pyproject.toml:

[build-system]
requires = ["setuptools"]
build-backend = "setuptools.build_meta"

[project]
name = "sample"
version = "0.1"

[project.scripts]
sample = "sample:__main__"

build project:

python -m venv build-venv
build-venv\Scripts\python.exe -m pip install build
build-venv\Scripts\python.exe -m build sampleproject

Install the built wheel with installer and display the distribution files:

python -m venv test-venv
test-venv\Scripts\python.exe -m pip install installer importlib-metadata
test-venv\Scripts\python.exe -m installer sampleproject\dist\sample-0.1-py3-none-any.whl
test-venv\Scripts\python.exe -c "from pprint import pprint; from importlib_metadata import distribution; pprint(distribution('sample').files)"

When using Python 3.12 or later to install the wheel and display the files the correct output is:

[PackagePath('sample-0.1.dist-info/METADATA'),
PackagePath('sample-0.1.dist-info/RECORD'),
PackagePath('sample-0.1.dist-info/WHEEL'),
PackagePath('sample-0.1.dist-info/entry_points.txt'),
PackagePath('sample-0.1.dist-info/top_level.txt'),
PackagePath('C:/temp/test-uninstall/test-venv/Scripts/sample.exe'),
PackagePath('sample/__init__.py'),
PackagePath('sample/__main__.py')]

When using Python 3.11 or 3.10 to install the wheel and display the files the executable script is missing:

[PackagePath('sample-0.1.dist-info/METADATA'),
PackagePath('sample-0.1.dist-info/RECORD'),
PackagePath('sample-0.1.dist-info/WHEEL'),
PackagePath('sample-0.1.dist-info/entry_points.txt'),
PackagePath('sample-0.1.dist-info/top_level.txt'),
PackagePath('sample/__init__.py'),
PackagePath('sample/__main__.py')]

The reason is the following difference in path operations:

>C:\python311\python.exe -c "from pathlib import Path, PurePosixPath; print(Path('C:/a') / PurePosixPath('C:/b/c'))"
C:\a\b\c
 
>C:\python312\python.exe -c "from pathlib import Path, PurePosixPath; print(Path('C:/a') / PurePosixPath('C:/b/c'))"
C:\b\c

This issue can be worked around by converting the PurePosixPath to str first:

>C:\python311\python.exe -c "from pathlib import Path, PurePosixPath; print(Path('C:/a') / str(PurePosixPath('C:/b/c')))"
C:\b\c

Would you be open to such a fix in

importlib_metadata/importlib_metadata/__init__.py

Line 1046 in f09a4bd

return self._path.parent / path

?