Re: [PATCH] rebase -i: interrupt rebase when "commit --amend" failed during "reword"

From: Junio C Hamano <gitster@pobox.com>
Date: Nov 29, 2011, 20:08 UTC
Message-ID: <7vk46isncq.fsf@alter.siamese.dyndns.org>
In-Reply-To: <1322496952-23819-2-git-send-email-andrew.kw.w@gmail.com>

Andrew Wong <andrew.kw.w@gmail.com> writes:

Show 7 quoted lines

> "commit --amend" could fail in cases like the user empties the commit
> message, or pre-commit failed.  When it fails, rebase should be
> interrupted, rather than ignoring the error and continue on rebasing.
> This gives users a way to gracefully interrupt a "reword" if they
> decided they actually want to do an "edit", or even "rebase --abort".
>
> Signed-off-by: Andrew Wong <andrew.kw.w@gmail.com>

Makes sense, especially if "commit" itself failed due to some unknown reason or a refusal from the pre-commit hook. Even though a user could have been using the "empty the commit log message and the original is kept" as a trick to recover from a botched rewording attempt and this change will regress for such use cases, I have a feeling that it does not matter.

Is there anything we should be saying more than "fatal: Cannot amend" to help users when this new "die" triggers? What is the recommended recovery procedure? Run "git commit --amend" after doing whatever is needed to fix the tree (e.g. if pre-commit refused because of a coding style violation, it may involve fixing the tree being committed; if it refused because of a typo in the log message, the tree itself may be OK and nothing needs to be done) and then "git rebase --continue"?

Show 17 quoted lines

>  git-rebase--interactive.sh |    3 ++-
>  1 files changed, 2 insertions(+), 1 deletions(-)
>
> diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
> index 804001b..669f378 100644
> --- a/git-rebase--interactive.sh
> +++ b/git-rebase--interactive.sh
> @@ -408,7 +408,8 @@ do_next () {
>  		mark_action_done
>  		pick_one $sha1 ||
>  			die_with_patch $sha1 "Could not apply $sha1... $rest"
> -		git commit --amend --no-post-rewrite
> +		git commit --amend --no-post-rewrite ||
> +			die_with_patch $sha1 "Cannot amend commit after successfully picking $sha1... $rest"
>  		record_in_rewritten $sha1
>  		;;
>  	edit|e)