From: Junio C Hamano <gitster@pobox.com>
Date: Thu, 17 Jul 2008 05:38:45 GMT
Subject: Re: [PATCH 1/2] t/test-lib.sh: Let test_must_fail fail on signals only
Message-ID: <7v3am9m5ne.fsf@gitster.siamese.dyndns.org>
In-Reply-To: <20080717051833.GA3100@sigio.intra.peff.net>

Jeff King <peff@peff.net> writes:

> On Tue, Jul 15, 2008 at 10:54:25PM -0700, Junio C Hamano wrote:
>
>> Anything that returns error() from its cmd_xxx() routine, for example,
>> would end up exiting with (-1).  Is it "such bogus" error codes, though?
>
> I think it is bogus, because it is being implicitly truncated to an
> unsigned 8-bit value (at least on Linux -- I have no idea what other
> platforms do). 

"Only the least significant 8 bits (that is, status & 0377) shall be
available to a waiting parent process".  So it is not just "at least on
Linux" but is a well defined behaviour.

http://www.opengroup.org/onlinepubs/000095399/functions/exit.html

I would however agree that when we do mean 255 we should probably write
255, not (-1).  It is easier to document things that way.