Quitting commit with co-authored actually commits

[dewyze]

If I run git dci without GIT_DUET_CO_AUTHORED_BY set, and then run :qa in vim. It will not commit.

If I run git commit/dci with GIT_DUET_CO_AUTHORED_BY set (and GIT_DUET_GLOBAL set), and then run :qa in vim, it will still make the commit either way.

[dewyze]

I am on git 2.11.0 and git duet 0.6.0

[jszwedko]

Thanks for the report!

This appears to be a regrettable side-effect of writing the trailer as part of the commit preparation (the prepare-commit-msg hook). Specifically with vim you can workaround it by doing :ca (exit nonzero), but I believe we should take further steps to address this.

Some half-baked ideas/thoughts:

• Adding a comment during the commit preparation above the trailers with something like # delete these trailers if you want to write an empty commit message
• Add a commit-msg hook that looks for commit messages that only have the Co-authored-by: trailers and exit 1 (this is the status code it currently aborts with for empty commit messages). Consider the implications of how this works with --no-verify which would skip this hook.
• Move this logic from a prepare-commit-msg hook to a commit-msg hook. The former seems to be theoretically the better place for it to live, but perhaps the latter is better from a practical stand point. Not crazy about this idea.
• Worst-case: document this new behavior in the README

I was initially confused that the Signed-off-by trailer didn't do the same thing, but it looks like git explicitly ignores these when looking for empty commit messages: https://github.com/git/git/blob/master/sequencer.c#L753-L789 . If only we could add some more to ignore.

I'll mark this as a bug since it is technically a regression in behavior.