bug#19157: 25.0.50; Horizontal auto-scrolling

[Eli Zaretskii]

> Date: Mon, 24 Nov 2014 09:29:29 +0100
> From: Dani Moncayo <dmoncayo@gmail.com>
> 
> > Recipe:
> >   emacs -Q
> >   M-x toggle-truncate-lines RET
> >   ; Visit the attached file
> >   Type: C-s t l s . c C-s C-s
> 
> Opps, as you surely have noticed, the intended recipe is this one:
> 
>    emacs -Q
>    ; Visit the attached file
>    M-x toggle-truncate-lines RET
>    Type: C-s t l s . c C-s C-s
> 

Fixed in 9faf591 on master.

The incorrect code in isearch.el was there since about forever.  I
have no idea why this problem is only visible on the trunk; I suspect
some recent redisplay optimization exposed it.  If you have time to
bisect, perhaps we will learn something non-trivial.

Thanks.