bug#25105: 26.0.50; diff navigation is broken

[Tino Calancha]

On Fri, 6 Jan 2017, Eli Zaretskii wrote:

> > From: Dima Kogan <dima@secretsauce.net>
> > Date: Thu, 05 Jan 2017 20:16:12 -0800
> > Cc: 25105@debbugs.gnu.org, Dmitry Gutov <dgutov@yandex.ru>,
> >         Tino Calancha <tino.calancha@gmail.com>, npostavs@users.sourceforge.net
> >
> > I consider the current behavior a significant improvement in usability,
> > but if there's a consensus that it's a step backward, then I'll go back
> > to carrying this patch in my local tree.
>
> Another alternative is to have a customizable option which will let
> users decide what behavior they want.
That would be OK.  I would suggest to set this option nil by default, 
i.e., disable the new feature by default for backward compatibility.