bug#21559: 25.0.50; auto-revert-mode breaks git rebase

[Eli Zaretskii]

> From: Dmitry Gutov <dgutov@yandex.ru>
> Date: Tue, 20 Feb 2018 02:17:51 +0200
> Cc: Michael Albinus <michael.albinus@gmx.de>
> 
> On 2/20/18 2:06 AM, Alexei Khlebnikov wrote:
> > 2018-02-20 0:41 GMT+01:00 Dmitry Gutov <dgutov@yandex.ru 
> > <mailto:dgutov@yandex.ru>>:
> > 
> >     Failing that, why don't we try something else first? If the problem
> >     occurs solely due to auto-revert-mode's calls to Git, let's try
> >     adding that environment variable binding inside auto-revert-handler.
> >     The patch is below. Does it solve the problem as well?
> > 
> > 
> > I've just tested - yes, it solves the problem as well!
> 
> Terrific, thank you.
> 
> What do others think? Michael, Eli?

Fine with me, but please add a comment there explaining why we do
that, as the relation between auto-revert and Git is entirely not
obvious.