Re: [PATCH v2 4/6] rebase --continue: refuse to commit after failed command

> If a commit cannot be picked because it would overwrite an untracked
> file then "git rebase --continue" should refuse to commit any staged
> changes as the commit was not picked. Do this by using the existing
> check for a missing author script in run_git_commit() which prevents
> "rebase --continue" from committing staged changes after failed exec
> commands.
>
> When fast-forwarding it is not necessary to write the author script as
> we're reusing an existing commit, not creating a new one. If a
> fast-forwarded commit is modified by an "edit" or "reword" command then
> the modification is committed with "git commit --amend" which reuses the
> author of the commit being amended so the author script is not needed.
> baf8ec8d3a (rebase -r: don't write .git/MERGE_MSG when fast-forwarding,
> 2021-08-20) changed run_git_commit() to allow a missing author script
> when rewording a commit. This changes extends that to allow a missing

> author script whenever the commit is being amended.
>
> If we're not fast-forwarding then we must remove the author script if
> the pick fails.
>
> Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>