Feature request: Support signed commits

[meshy]

I have found that git-revise strips GPG signatures from commits.

This seems better than leaving invalid signatures behind, but still seems unfortunate, especially given there is no visible warning.

Is it possible to sign revised commits as part of the revision process?

[mystor]

The signatures are stripped from commits as I'm changing the commit, and can't just leave the old GPG signature behind. As you noted, leaving it behind would "break" the commit, as it would have an invalid signature.

It should be possible to allow git-revise to re-sign each rewritten commit with your personal GPG key. This would need to be done in a similar way to git commit -S, perhaps as git revise -S, perhaps also respecting the commit.gpgSign config variable.

Unfortunately, git-revise generates the entirety of all commit objects internally, meaning we couldn't lean on the existing implementation within git commit to handle the signing for us. Instead, logic to add signatures to commit objects would need to be added to Repository.new_commit, based on the logic in git (technical docs, do_sign_commit, sign_buffer).

It may also be possible to keep signing out of the core logic by performing a final signing pass over the modified commit stack after rewriting using existing git commands. I'm not sure how much simpler/easier that would be to implement, however.

I don't personally work with GPG signed commits often, so I'm unlikely to work on this. I'd be open to reviewing a pull-request to add support for a feature like this, though.