bug#6036: bidi scrolling bug

[Eli Zaretskii]

> Cc: eliz@gnu.org
> From: Juanma Barranquero <lekktu@gmail.com>
> Date: Mon, 26 Apr 2010 11:21:52 +0200
> 
>    emacs -Q
> 
> then evaluate
> 
>   (setq scroll-conservatively most-positive-fixnum)
>   (setq-default bidi-display-reordering t)
> 
> to use line-by-line scrolling.
> 
> Then C-x C-f abbrev.el, and press <down> until the cursor reaches the
> ^L at line 73.
> 
> The buffer is suddenly recentered. Moreover, if you then move up the
> cursor to just after the ^L and press <left>, the cursor jumps to the
> end of the first line in the window.

There was a general problem with lines that end in glyphs from display
tables.  Should be fixed now (revno 100417).