Re: [BUG] fixup commit is dropped during rebase if subject = branch name

[Johannes Altmanninger <aclopte@gmail.com>]

On Sat, Sep 17, 2022 at 04:45:17PM +0200, Erik Cervin Edin wrote:
> Thank you for filling out a Git bug report!
> Please answer the following questions to help us understand your issue.
> 
> What did you do before the bug happened? (Steps to reproduce your issue)
>   dir=rebase-fixup-subject-equals-branch-name
>   mkdir $dir
>   cd $dir
>   git init --initial-branch=main
>   git commit -m init --allow-empty
>   git tag init
> 
>   # failure
>   seq 1 3 >> bar && git add bar && git commit -m main
>   git tag -f x
>   seq 4 6 >> bar && git add bar && git commit -m bar
>   seq 7 9 >> bar && git add bar && git commit --fixup :/main
>   git -c sequence.editor=: rebase --autosquash --interactive x

Huh, this silently discards the fixup commit, without applying it.

If "foo" is a valid refspec, then the autosquash machinery will apply to it
all fixup commits with subject "fixup! foo".
The problem you hit is that "foo" points to the fixup commit itself - which
is the only destination commit that definitely won't work.

Here is a possible fix:

diff --git a/sequencer.c b/sequencer.c
index 79dad522f5..7cbd8c2595 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -6231,3 +6231,3 @@ int todo_list_rearrange_squash(struct todo_list *todo_list)
 				 (commit2 =
-				  lookup_commit_reference_by_name(p)) &&
+				  lookup_commit_reference_by_name(p)) != item->commit &&
 				 *commit_todo_item_at(&commit_todo, commit2))