Fix bug #9184 with org-agenda crashing under bidi redisplay.

 src/xdisp.c (compute_display_string_pos): Don't use cached display
 string position if the buffer had its restriction changed.

src/ChangeLog

+2011-07-28  Eli Zaretskii  <eliz@fencepost.gnu.org>
+
+	* xdisp.c (compute_display_string_pos): Don't use cached display
+	string position if the buffer had its restriction changed.
+	(Bug#9184)
+
 2011-07-28  Paul Eggert  <eggert@cs.ucla.edu>
 
 	* callproc.c (Fcall_process): Use 'volatile' to avoid vfork clobbering.

src/xdisp.c

@@ -3182,7 +3182,8 @@ compute_display_string_pos (struct text_pos *position,
 	b = XBUFFER (object);
       if (b == cached_disp_buffer
 	  && BUF_MODIFF (b) == cached_disp_modiff
-	  && BUF_OVERLAY_MODIFF (b) == cached_disp_overlay_modiff)
+	  && BUF_OVERLAY_MODIFF (b) == cached_disp_overlay_modiff
+	  && !b->clip_changed)
 	{
 	  if (cached_prev_pos >= 0
 	      && cached_prev_pos < charpos && charpos <= cached_disp_pos)