Re: [PATCH v2 3/3] git-filter-branch: make the error msg when missing branch more open

From: Junio C Hamano <gitster@pobox.com>
Date: May 11, 2017, 03:53 UTC
Message-ID: <xmqq1srwcamw.fsf@gitster.mtv.corp.google.com>
In-Reply-To: <20170503210726.24121-3-jn.avila@free.fr>

Jean-Noel Avila <jn.avila@free.fr> writes:

Show 25 quoted lines

> git-filter-branch requires the specification of a branch by one way or
> another. If no branch appears to have been specified, we know the user
> got the usage wrong but we don't know what they were trying to do ---
> e.g. maybe they specified the ref to rewrite but in the wrong place.
>
> The safest solution is to just print the usage in this case.
>
> Signed-off-by: Jean-Noel Avila <jn.avila@free.fr>
> ---
>  git-filter-branch.sh | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/git-filter-branch.sh b/git-filter-branch.sh
> index 2b8cdba15..bda2bae23 100755
> --- a/git-filter-branch.sh
> +++ b/git-filter-branch.sh
> @@ -239,7 +239,7 @@ git rev-parse --no-flags --revs-only --symbolic-full-name \
>  sed -e '/^^/d' "$tempdir"/raw-heads >"$tempdir"/heads
>  
>  test -s "$tempdir"/heads ||
> -	die "Which ref do you want to rewrite?"
> +	usage
>  
>  GIT_INDEX_FILE="$(pwd)/../index"
>  export GIT_INDEX_FILE

I tend to agree with Ævar on this one. It is not apparent to the end user after this change what exactly was wrong in the input; for that matter, it is not even clear that the command is refusing to run because it found problem with the input.

Trying to move away from asking "I didn't get that, what did you mean?" is one thing, and that can be done by saying "no ref to rewrite given" or something. We may want to make it into a more "positive" nudge, telling the user what to do, e.g. "give me the refs to rewrite."

Thanks.