From: Junio C Hamano <gitster@pobox.com>
Date: Fri, 15 Jul 2016 18:19:23 GMT
Subject: Re: [PATCH 05/12] check_connected: relay errors to alternate descriptor
Message-ID: <xmqqbn1yn4r8.fsf@gitster.mtv.corp.google.com>
In-Reply-To: <20160715103203.GE19271@sigill.intra.peff.net>

Jeff King <peff@peff.net> writes:

> +	/*
> +	 * If non-zero, send error messages to this descriptor rather
> +	 * than stderr. The descriptor is closed before check_connected
> +	 * returns.
> +	 */
> +	int err_fd;

Theoretically speaking it may be possible that a caller may want to
write to fd#0 if it closed the standard input before creating the
output channel for multiplexing into a sideband, but I think this
design strikes a good balance between the theoretical correctness
and usability.  Using err_fd == -1 as "no redirect" may allow the
caller to redirect the errors to fd#0, but that forces normal users
to explicitly set this field to -1.