bug#15951: 24.3.50; C-n and C-p don't work in narrowed buffer

[Eli Zaretskii]

> From: Stephen Berman <stephen.berman@gmx.net>
> Date: Fri, 22 Nov 2013 12:59:21 +0100
> Cc: 15951@debbugs.gnu.org
> 
> On Fri, 22 Nov 2013 13:14:49 +0900 Katsumi Yamaoka <yamaoka@jpl.org> wrote:
> 
> > Run Emacs with the -Q option, create a new buffer, and put those
> > three lines there,
> >
> > foo
> > bar
> > baz
> >
> > type  C-p  C-p  C-SPC  M-> , and type `C-x n n' so that the last
> > two lines are visible.  Then you will see C-n and C-p don't work.
> 
> This is evidently more fallout from enabling cache-long-scans: if you
> set this to nil, C-n and C-p work again.

No, this is cache-long-scans doing us a favor and exposing a bug in
our code that uses one of the caches.

Fixed in trunk revision 115190.

Thanks.