Adding a commit during rebase causes incorrectly detected rewritten commit

[alan-nf]

Description of the bug

Current repo state

➜ git:(feature4) git sl
◇ 70bcbf7a 1h (main, remote origin/main) Initial commit
┃
◯ 2d27ec27 1h (feature1) feature1 work
┃
◯ bff4f430 1h (feature2) feature2 work
┃
◯ 5cd580b9 25m (feature3) feature3 work
┃
● e106b908 25m (feature4) feature4 work

Initiate a rebase

➜ git:(feature4) git rebase -i HEAD~4

change bff4f430 from pick to edit

branchless: processing 1 update: ref HEAD
Stopped at bff4f43... feature2 work
You can amend the commit now, with

git commit --amend

Once you are satisfied with your changes, run

git rebase --continue

Create a NEW commit (no amend)

➜ git:(bff4f43) echo "more stuff" >> feature2.txt && git commit -a -m "more feature2 work"

branchless: processing 1 update: ref HEAD
branchless: processed commit: 5a276e8b more feature2 work
[detached HEAD 5a276e8] more feature2 work
1 file changed, 1 insertion(+)

Current repo state

➜ git:(5a276e8) git sl
◇ 70bcbf7a 1h (main, remote origin/main) Initial commit
┃
◯ 2d27ec27 1h (feature1) feature1 work
┃
◯ bff4f430 1h (feature2) feature2 work
┣━┓
┃ ◯ 5cd580b9 26m (feature3) feature3 work
┃ ┃
┃ ◯ e106b908 26m (feature4) feature4 work
┃
● 5a276e8b 2s more feature2 work

Continue with rebase

➜ git:(5a276e8) git rebase --continue
branchless: processing 1 update: ref HEAD
branchless: processed commit: e91c1769 feature3 work
branchless: processing 1 update: ref HEAD
branchless: processed commit: c514ede7 feature4 work
branchless: processing 1 update: branch feature4
branchless: processing 3 rewritten commits
branchless: This operation abandoned 1 commit and 2 branches (feature2, feature3)!
branchless: Consider running one of the following:
branchless: - git restack: re-apply the abandoned commits/branches
branchless: (this is most likely what you want to do)
branchless: - git smartlog: assess the situation
branchless: - git hide [...]: hide the commits from the smartlog
branchless: - git undo: undo the operation
branchless: - git config branchless.restack.warnAbandoned false: suppress this message
Successfully rebased and updated refs/heads/feature4.

Current repo state

➜ git:(feature4) git sl
◇ 70bcbf7a 1h (main, remote origin/main) Initial commit
┃
◯ 2d27ec27 1h (feature1) feature1 work
┃
✕ bff4f430 1h (rewritten as 5a276e8b) (feature2) feature2 work # This is WRONG ❌
┣━┓
┃ ✕ 5cd580b9 26m (rewritten as e91c1769) (feature3) feature3 work
┃
◯ 5a276e8b 23s more feature2 work
┃
◯ e91c1769 2s feature3 work
┃
● c514ede7 2s (feature4) feature4 work

I cannot git restack anymore

➜ git:(feature4) git restack
This operation failed because it would introduce a cycle:
┌─ᐅ 5a276e8b more feature2 work
└── 5a276e8b more feature2 work

Expected behavior

bff4f430 is NOT rewritten as 5a276e8b. I think the log should read like this:

➜  git:(feature4) git sl
◇ 70bcbf7a 1h (main, remote origin/main) Initial commit
┃
◯ 2d27ec27 1h (feature1) feature1 work
┃
◯ bff4f430 1h (feature2) feature2 work
┣━┓
┃ ✕ 5cd580b9 26m (rewritten as e91c1769) (feature3) feature3 work
┣━┓
┃ ✕ e106b908 26m (rewritten as c514ede7) (feature4) feature4 work
┃
◯ 5a276e8b 23s more feature2 work
┃
◯ e91c1769 2s feature3 work
┃
● c514ede7 2s (feature4) feature4 work

Or, if restack shouldn't even be required here, we should not show the rewritten commits and the log should be:

➜  git:(feature4) git sl
◇ 70bcbf7a 1h (main, remote origin/main) Initial commit
┃
◯ 2d27ec27 1h (feature1) feature1 work
┃
◯ bff4f430 1h (feature2) feature2 work
┃
◯ 5a276e8b 23s more feature2 work
┃
◯ e91c1769 2s feature3 work
┃
● c514ede7 2s (feature4) feature4 work

Actual behavior

Log says:

✕ bff4f430 1h (rewritten as 5a276e8b) (feature2) feature2 work # This is WRONG ❌

restack is broken

Version of git-branchless

git-branchless 0.3.9

Version of git

git 2.32.0

Version of rustc

rustc 1.59.0

Automated bug report

No response

[arxanas]

Thanks for the report! I never use edit with git rebase -i, so I wouldn't have noticed this myself. For the future, you might want to check out the commit directly as discussed here #315 (comment), rather than use edit.

To restore your git restack, you can clear the git-branchless database by running rm .git/branchless/db.sqlite3. Make sure that you have branches pointing to all of the commits you care about (but it sounds like you're using a primarily branch-based workflow, so you probably don't need to worry).

The rewrite information comes from the data provided by Git via the post-rewrite hook, which is invoked at the end of the git rebase. Most likely I didn't handle the case of edit correctly.

[arxanas]

This is also kind of related to the item "Aborted git rebases leave any applied commits in the smartlog." in #1. The best overall solution might be to implement our own git rebase -i alternative (#177) which interoperates better with git-branchless, rather than to continue working around git rebase -i issues.