gerrit: fallback review URL when push has no new changes

[godnight10061]

Fixes #10188

When pushing to Gerrit, if a commit was already pushed outside GitButler, Gerrit may reject with (no new changes). GitButler treats this as success, but the push output contains no change URLs, so no Gerrit metadata was recorded and the UI kept the commit as 'unpushed' / missing the CR link.

This adds a fallback in but-gerrit to derive the Gerrit host from the repo push remote and generate a review URL from the commit's GitButler change UUID (the same I<sha1(uuid)> Change-Id used in trailers), e.g. https://<gerrit-host>/q/<change-id>.

Tests

• cargo test -p but-gerrit

[vercel]

@godnight10061 is attempting to deploy a commit to the GitButler Team on Vercel.

A member of the Team first needs to authorize it.

[Byron]

Thanks a lot for contributing, it's much appreciated!

And while I would have a thing or two to say about the test (which I would probably just refactor myself), I lack experience with Gerrit to understand the problem the PR is solving in the first place.

Maybe @krlvi could see if this pans out (and maybe even try it) beforehand. Alternatively, and independently, maybe @godnight10061 could make a before and after video to show how the fix translates to the real world?

Thanks again.

[godnight10061]

Maybe @krlvi could see if this pans out (and maybe even try it) beforehand. Alternatively, and independently, maybe @godnight10061 could make a before and after video to show how the fix translates to the real world?

Thanks again.

before.mp4

after.mp4

How to reproduce:

• In GitButler: Project Settings → General → “Gerrit Configuration” → toggle ON.
• In GitButler: make a tiny change and create a commit in GitButler (so it has a GitButler change id).
  • Before (bug): push “succeeds”, but the commit still shows Local (circle) and Push stays enabled (still thinks
    there are unpushed commits).
  • After (fixed): commit flips to Local and remote (diamond) and Push disables (“No commits to push”).
    (Depending on URL format you may or may not also see a Gerrit pill/link.)

[krlvi]

Hey, thank you for this contribution. This fallback is indeed helpful

[godnight10061]

Thanks for merging! I'm glad the fallback will be useful.