[hakarrr]

Problem

format_path() uses a string prefix to decide whether a path is inside HOME. With HOME=/home/user, /home/username/file is rendered as ~/../username/file, even though it is not inside the home directory. The documented abbreviation is intended for the home directory and its descendants.

Change

Require either an exact home-directory match or a prefix ending at a path separator. Preserve normalization, trailing separators, exact-home rendering and filesystem-root homes. The implementation keeps the project's older Python compatibility rather than using os.path.commonpath.

Tests

• Three new test methods cover sibling prefixes, descendants, exact home, parent paths, normalization, trailing separators, filesystem-root homes and an empty HOME.
• The boundary test fails on the unchanged base; root/empty-home tests are controls.
• Full suite: 72 passed on CPython 3.9.25, 3.10.12, 3.11.17 and 3.12.15. The unchanged base has 69 tests.
• Full combined line/branch coverage is 91%; the modified path-formatting branches are covered.
• Changed-file flake8 including docstring checks, git diff --check, wheel and sdist passed.

Python 2, older Python versions, Windows and macOS were not tested locally. Hosted CI has not been verified green. No test or CI configuration changed.