bug#9495: 24.0.50; Segfault in try_cursor_movement

[Eli Zaretskii]

> From: Johan Bockgård <bojohan@gnu.org>
> Cc: 9495@debbugs.gnu.org
> Date: Wed, 14 Sep 2011 21:50:29 +0200
> 
> emacs -Q -eval '(setq line-move-visual nil truncate-lines t track-eol t)'
> 
> C-u 100 x RET
> y <up>
> 
> At this point, in try_cursor_movement, point is in the "x" line, the
> window has not yet hscrolled, and the value of hpos is just after the
> last valid element in glyphs[TEXT_AREA].
> 
> (It only actually crashes some of the time, of course.)

Thanks, I committed your patch with a minor variation.