Re: [PATCH] rebase -i: abort cleanly if the editor fails to launch

From: Junio C Hamano <gitster@pobox.com>
Date: Dec 19, 2009, 20:44 UTC
Message-ID: <7v8wcy7kyc.fsf@alter.siamese.dyndns.org>
In-Reply-To: <4B2CC133.9010704@gmail.com>

Björn Gustavsson <bgustavsson@gmail.com> writes:

Show 15 quoted lines

> If the user's configured editor is emacsclient, the editor
> will fail to launch if emacs is not running and the git
> command that tried to lanuch the editor will abort. For most
> commands, all you have to do is to start emacs and repeat
> the command.
>
> The "git rebase -i" command, however, aborts without cleaning
> the "$GIT_DIR/rebase-merge" directory if it fails to launch the
> editor, so you'll need to do "git rebase --abort" before
> repeating the rebase command.
>
> Change "git rebase -i" to terminate using "die_abort" (instead of
> with "die") if the initial launch of the editor fails.
>
> Signed-off-by: Björn Gustavsson <bgustavsson@gmail.com>

Two questions:

 - Is emacsclient the _only_ editor that can exit with non-zero status to
   signal an error condition "the user invoked me to edit an existing
   file, but I ended up not letting the user edit it"?

 - Are there editors that let you exit with non-zero status on demand?

The above is not a complaint to your log message, but is a genuine request for information.

An editor that can exit with non-zero status on demand could use this codepath to abort the rebase, when a user realizes that the edit s/he has done so far was completely bogus [*1*]. In such a case, the existing error message "Could not execute editor" may sound funny.

Regardless of that small issue, I think the patch to clean-up makes sense.

Thanks.

[Footnote]

*1* We interpret a completely empty $TODO as a signal from the user to abort the sequencer (the literal interpretation of such a $TODO would be to not pick any commits, which could be a source of potential confusion), so it is not an issue in practice if your editor does not allow you to exit with non-zero status to signal an exception. You can remove all lines and exit the editor normally instead.