Fix bug #9218 with slow cursor motion and scrolling Org Mode buffers.

 src/dispextern.h (struct bidi_it): New member disp_prop_p.
 src/xdisp.c: Remove one-slot cache of display string positions.
 (compute_display_string_pos): Accept an additional argument
 DISP_PROP_P; callers changed. Scan at most 5K characters forward
 for a display string or property.  If found, set DISP_PROP_P
 non-zero.
 src/bidi.c (bidi_fetch_char): Accept an additional argument
 DISP_PROP_P, and pass it to compute_display_string_pos.  Only
 handle text covered by a display string if DISP_PROP_P is returned
 non-zero.  All callers of bidi_fetch_char changed.

1 files changed, 18 insertions, 0 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 59f09515829..3717924ff68 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,21 @@
+2011-08-02  Eli Zaretskii  <eliz@gnu.org>
+
+        Fix slow cursor motion and scrolling in large buffers with
+        selective display, like Org Mode buffers.  (Bug#9218)
+
+        * dispextern.h (struct bidi_it): New member disp_prop_p.
+
+        * xdisp.c: Remove one-slot cache of display string positions.
+        (compute_display_string_pos): Accept an additional argument
+        DISP_PROP_P; callers changed. Scan at most 5K characters forward
+        for a display string or property.  If found, set DISP_PROP_P
+        non-zero.
+
+        * bidi.c (bidi_fetch_char): Accept an additional argument
+        DISP_PROP_P, and pass it to compute_display_string_pos.  Only
+        handle text covered by a display string if DISP_PROP_P is returned
+        non-zero.  All callers of bidi_fetch_char changed.
+
 2011-08-02  Stefan Monnier  <monnier@iro.umontreal.ca>
 
         * keymap.c (Fdefine_key): Fix Lisp_Object/int mixup; apply some CSE.