From: Johannes Sixt <j.sixt@viscovery.net>
Date: Mon, 21 Dec 2009 07:18:37 GMT
Subject: Re: possible code error at run_command.c
Message-ID: <4B2F214D.2020905@viscovery.net>
In-Reply-To: <1976ea660912202246k45732bf2p111bbeb78047693e@mail.gmail.com>

Frank Li schrieb:
> int start_command(struct child_process *cmd)
> {
> 	int need_in, need_out, need_err;
> 	int fdin[2], fdout[2], fderr[2];
> 	int failed_errno = failed_errno;
> 
> I have not found failed_errno as global variable.
> failed_errno = failed_errno means nothing.

This is a commonly used idiom to avoid an (incorrect) compiler warning
about an uninitialized variable.

Strictly speaking, I think that you are right by saying "means nothing"
because the use of the uninitialized variable invokes undefined behavior
(and for this reason, I dislike this construct), but in practice it will
not make a difference.

-- Hannes