Re: [PATCH] difftool: always honor "command not found" exit code

"Tom Tanner (BLOOMBERG/ LONDON)" [off-list ref] writes:

From: gitster@pobox.com
To: john@keeping.me.uk
Cc: Tom Tanner (BLOOMBERG/ LONDON), davvid@gmail.com, git@vger.kernel.org
At: 08/14/16 04:21:18

John Keeping [off-list ref] writes:
...

quoted

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.

Would it be possible to also treat signals (128 and above) as
'special' values as well (as I've seen some merge tools self
destruct like that from time to time)

Certainly, it feels safer to notice an unusual exit status code and
error out to force the user to take notice, but that reasoning
assumes that "128 and above" are noteworthy exceptions.

I do not have a strong opinion on that part.