Fix excessive calls to bidi_shelve_cache reported in bug #15555.

 src/xdisp.c (move_it_in_display_line_to): Save the iterator state in ppos_it
 only once per call.  Reimplement the method used to return to the
 best candidate position if all the positions found in display line
 are beyond TO_CHARPOS.  This cuts down the number of calls to
 bidi_shelve_cache, which moves a lot of stuff when lines are long
 and include bidirectional text.

1 files changed, 6 insertions, 0 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 3c063ca3c0b..4bb47197106 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -5,6 +5,12 @@
         (try_cursor_movement): Don't use cursor position if
         set_cursor_from_row failed to compute it.  This avoids assertion
         violations in MATRIX_ROW.
+        (move_it_in_display_line_to): Save the iterator state in ppos_it
+        only once per call.  Reimplement the method used to return to the
+        best candidate position if all the positions found in display line
+        are beyond TO_CHARPOS.  This cuts down the number of calls to
+        bidi_shelve_cache, which moves a lot of stuff when lines are long
+        and include bidirectional text.  (Bug#15555)
 
 2014-02-20  Glenn Morris  <rgm@gnu.org>