bug#23075: 24.5; vc-git-command should use coding-system-for-read

[Eli Zaretskii]

> From: Andreas Schwab <schwab@linux-m68k.org>
> Cc: Eli Zaretskii <eliz@gnu.org>,  23075@debbugs.gnu.org,  Nikolay 
> Kudryavtsev <nikolay.kudryavtsev@gmail.com>
> Date: Mon, 21 Mar 2016 18:57:55 +0100
> 
> Óscar Fuentes <ofv@wanadoo.es> writes:
> 
> > Maybe this is related: on a Kubuntu 15.08 box with a 2 week old emacs
> > 25.0.92.2 and git 2.5.0, if I visit etc/HELLO (on a Emacs checkout) and
> > do `C-x v l' and then, on the *vc-change-log* buffer, put the cursor on
> > the last commit (etc/HELLO: Add Armenian and Mongolian greetings.) and
> > press `d', the ensuing *vc-diff* buffer contains mostly garbage.
> 
> Garbage in which way?  The diff output is encoded in iso-2022-7bit, but
> Emacs doesn't know that since the coding cookie is missing.

The OP seems to suggest that the correct encoding is already known,
since we visited the file itself.