Hi Uwe
On 30/05/2023 10:21, Uwe Kleine-König wrote:
Hello,
I found a bug in git rebase and how notes are retained using
uwe@taurus:~/tmp/gittest$ git version
git version 2.41.0.rc2.161.g9c6817b8e7dd
, it also happens with 2.39.2.
Here comes a reproducer:
Thanks for reporting this and taking the time to provide an easy
reproducer. I think the problem is that when git drops the commit in
do_pick_commit() it still gets recorded as rewritten and so the notes
are copied. To fix it we need to improve do_pick_commit() to return a
value indicating that the commit was dropped so that we don't call
record_in_rewritten() in pick_commits().
Best Wishes
Phillip
- Create some initial git history, just three commits A, B and C:
uwe@taurus:~/tmp/gittest$ git init
Initialized empty Git repository in /home/uwe/tmp/gittest/.git/
uwe@taurus:~/tmp/gittest$ for i in A B C; do echo content $i >> file ; git add file ; git commit -m "$i" ; git notes add -m "notes for $i" ; git tag $i ; done
[main (root-commit) db2548de5a3c] A
1 file changed, 1 insertion(+)
create mode 100644 file
[main 2b8fa82afb3c] B
1 file changed, 1 insertion(+)
[main 3dd5e4a2037e] C
1 file changed, 1 insertion(+)
- Pick C on top of A:
uwe@taurus:~/tmp/gittest$ git checkout A
HEAD is now at db2548de5a3c A
uwe@taurus:~/tmp/gittest$ git cherry-pick C
Auto-merging file
CONFLICT (content): Merge conflict in file
error: could not apply 3dd5e4a2037e... C
hint: After resolving the conflicts, mark them with
hint: "git add/rm <pathspec>", then run
hint: "git cherry-pick --continue".
hint: You can instead skip this commit with "git cherry-pick --skip".
hint: To abort and get back to the state before "git cherry-pick",
hint: run "git cherry-pick --abort".
Recorded preimage for 'file'
uwe@taurus:~/tmp/gittest$ { echo content A; echo content C; } > file
uwe@taurus:~/tmp/gittest$ git add file
uwe@taurus:~/tmp/gittest$ git cherry-pick --continue
Recorded resolution for 'file'.
[detached HEAD 6cfc9b7bd437] C
Date: Tue May 30 11:02:13 2023 +0200
1 file changed, 1 insertion(+)
- Rebase {B, C} on top of A + C' (which results in skipping C):
uwe@taurus:~/tmp/gittest$ git rebase HEAD C
Auto-merging file
CONFLICT (content): Merge conflict in file
error: could not apply 2b8fa82afb3c... B
hint: Resolve all conflicts manually, mark them as resolved with
hint: "git add/rm <conflicted_files>", then run "git rebase --continue".
hint: You can instead skip this commit: run "git rebase --skip".
hint: To abort and get back to the state before "git rebase", run "git rebase --abort".
Recorded preimage for 'file'
Could not apply 2b8fa82afb3c... B
uwe@taurus:~/tmp/gittest$ { echo content A; echo content B; echo content C; } > file
uwe@taurus:~/tmp/gittest$ git add file
uwe@taurus:~/tmp/gittest$ git rebase --continue
Recorded resolution for 'file'.
[detached HEAD e5b3e28216f2] B
1 file changed, 1 insertion(+)
dropping 3dd5e4a2037ecd31f5470561638cb065434eabbc C -- patch contents already upstream
Successfully rebased and updated detached HEAD.
Now I have:
uwe@taurus:~/tmp/gittest$ git log --pretty=oneline --abbrev-commit --notes
e5b3e28216f2 (HEAD) B
Notes:
notes for B
notes for C
6cfc9b7bd437 C
db2548de5a3c (tag: A) A
Notes:
notes for A
The surprising part here is that (the new) B also has C's note. I would
have expected that it only has its own one. I quickly looked into the
source code, but didn't find an easy fix because the code that notices
that C should be dropped (in do_pick_commit()) isn't where the note is
copied (which I didn't find).
Best regards
Uwe
