bug#8487: bidi-related crash in speedbar

[Eli Zaretskii]

> From: Juanma Barranquero <lekktu@gmail.com>
> Date: Tue, 12 Apr 2011 22:10:16 +0200
> 
> Package: emacs
> Version: 24.0.50
> 
> emacs -Q --eval "(setq-default bidi-display-reordering t)" -f speedbar
> ;; Move the cursor until the end of the speedbar buffer
> 
> 
> Breakpoint 1, w32_abort () at w32fns.c:7190
> 7190      button = MessageBox (NULL,
> (gdb) bt
> #0  w32_abort () at w32fns.c:7190
> #1  0x0133e498 in bidi_paragraph_init (dir=NEUTRAL_DIR,
> bidi_it=0x88eaa8, no_default_p=1) at bidi.c:610
> #2  0x011805dc in handle_invisible_prop (it=0x88e500) at xdisp.c:3671

Like I thought: a completely different bug than 7616.  Should be fixed
now (revision 103905).

Of course, plenty of funny behavior is still there; e.g., try up-arrow
or even right-arrow (feel free to submit a separate bug report with
all the symptoms), but at least it no longer crashes that easily.  I
need to take a good look at the bidi operations in the presence of
invisible text, sigh.