From: Junio C Hamano <gitster@pobox.com>
Date: Sun, 14 Aug 2016 03:21:14 GMT
Subject: Re: [PATCH] difftool: always honor "command not found" exit code
Message-ID: <xmqqtweokpcl.fsf@gitster.mtv.corp.google.com>
In-Reply-To: <20160813113028.uwedje6fzuc3cuzr@john.keeping.me.uk>

John Keeping <john@keeping.me.uk> writes:

> At the moment difftool's "trust exit code" logic always suppresses the
> exit status of the diff utility we invoke.  This is useful because we
> don't want to exit just because diff returned "1" because the files
> differ, but it's confusing if the shell returns an error because the
> selected diff utility is not found.
>
> POSIX specifies 127 as the exit status for "command not found" and 126
> for "command found but is not executable" [1] and at least bash and dash
> follow this specification, while diff utilities generally use "1" for
> the exit status we want to ignore.
>
> Handle 126 and 127 as special values, assuming that they always mean
> that the command could not be executed.

Sounds like a reasonable thing to do.  Will queue; thanks.