From: Junio C Hamano <gitster@pobox.com>
Date: Sun, 23 Jan 2011 23:32:12 GMT
Subject: Re: [PATCH] No color diff when redirecting to file
Message-ID: <7voc77mc1v.fsf@alter.siamese.dyndns.org>
In-Reply-To: <vpq39oj4jfz.fsf@bauges.imag.fr>

Matthieu Moy <Matthieu.Moy@grenoble-inp.fr> writes:

> Johannes Sixt <j6t@kdbg.org> writes:
>
>> That said, I cannot reproduce. Perhaps your configuration says 
>> color.ui=always? If so, then this is expected behavior and not a bug, IMO.
>
> I think you're right.
>
> I tested this (without the patch):
>
> git diff
> => I get color, because I have color.ui = auto
>
> git diff | cat
> => I don't get color
>
> git diff --color=auto | cat
> => no color
>
> git diff --color=always | cat
> => colors, because I've asked
>
> this seems to be just the right behavior.

Overall I agree with the above observation, but the original poster says
"redirecting into a _file_".

Another possibility is that the mysterious platform the original poster
did not mention has a broken istty() that mistakes a file descriptor going
to a file (instead of a pipe to another process) as connected to a tty.