mutter/doc/git-conventions.md

Git conventions

Commit Messages

Commit messages should follow the GNOME commit message guidelines. We require an URL to either an issue or a merge request in each commit. Try to always prefix commit subjects with a relevant topic, such as compositor: or clutter/actor:, and it's always better to write too much in the commit message body than too little.

If a commit fixes an issue and that issue should be closed, add URL to it in the bottom of the commit message and prefix with Closes:.

Do not add any Part-of: line, as that will be handled automatically when merging.

The Fixes tag

If a commit fixes a regression caused by a particular commit, it can be marked with the Fixes: tag. To produce such a tag, use

git show -s --pretty='format:Fixes: %h ("%s")' <COMMIT>

or create an alias

git config --global alias.fixes "show -s --pretty='format:Fixes: %h (\"%s\")'"

and then use

git fixes <COMMIT>

Example

compositor: Also consider dark matter when calculating paint volume

Ignoring dark matter when calculating the paint volume missed the case where
compositing happens in complete vacuum.

Fixes: 123abc123ab ("compositor: Calculate paint volume ourselves")
Closes: https://gitlab.gnome.org/GNOME/mutter/-/issues/1234