Git replay

Posted Feb 28, 2024 10:52 UTC (Wed) by Tobu (subscriber, #24111)
In reply to: Git replay by newren
Parent article: Git 2.44.0 released

Glad folks are finding it useful. Note, though, that this only works for linear histories; if any of the commits in the range is a merge, you'll hit "replaying merge commits is not yet supported". There are plans to support merge commits (fairly detailed ones), but it doesn't exist yet.

Yes, for me at least this is enough: stacking non-merge commits as I would with git rebase.

Why do you need to start with a clean work tree? Have you found a bug, or are you being careful about starting with a clean worktree because you are using a hard reset afterward and that would have problems with the changes? (Part of the point of git replay is that you don't necessarily want or need to check out the result afterwards, so having a clean worktree should be irrelevant for such cases.)

The second: because I pipe into update-refs updating the current branch, followed by a hard reset. If there was a way to advance the current branch with autostash, that would be safer.

I'm used to working with low-level and high-level git commands depending on what works, and currently I can work with replay as a low-level command, git filter-branch to prune the empty commits (git filter-branch --prune-empty linus/master.. in this example — I looked at filter-repo and it doesn't take ranges), and finally git update-ref with manual stashing.

I'm not sure yet what would be a reasonable high-level interface: presumably just updating the refs from git replay would work (git replay --update-refs --autostash). Mimicking the rebase interface is an option but I don't know if I'd use it, because the point for me is not to reflect intermediate states inside the worktree, and that seems to preclude the interactive bits like --continue / --skip / --abort. Another totally different approach would be to stash worktree timestamps with their blob hashes somewhere and apply them back for unchanged files; then updating the worktree with in-between states wouldn't be a problem.