Fix bug #12930 with vertical-motion through a display string.

 src/indent.c (Fvertical_motion): If the starting position is covered
 by a display string, return to one position before that, to avoid
 overshooting it inside move_it_to.

2 files changed, 13 insertions, 1 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index f7cb0fe850f..f760adf313f 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,9 @@
+2012-11-21  Eli Zaretskii  <eliz@gnu.org>
+
+        * indent.c (Fvertical_motion): If the starting position is covered
+        by a display string, return to one position before that, to avoid
+        overshooting it inside move_it_to.  (Bug#12930)
+
 2012-11-20  Daniel Colascione  <dancol@dancol.org>
 
         * w32fns.c (Fx_file_dialog):
diff --git a/src/indent.c b/src/indent.c
index bbc944d2518..33322287c9d 100644
--- a/src/indent.c
+++ b/src/indent.c
@@ -2057,7 +2057,13 @@ whether or not it is currently displayed in some window.  */)
            comment said this is "so we don't move too far" (2005-01-19
            checkin by kfs).  But this does nothing useful that I can
            tell, and it causes Bug#2694 .  -- cyd */
-        move_it_to (&it, PT, -1, -1, -1, MOVE_TO_POS);
+        /* When the position we started from is covered by a display
+           string, move_it_to will overshoot it, while vertical-motion
+           wants to put the cursor _before_ the display string.  So in
+           that case, we move to buffer position before the display
+           string, and avoid overshooting.  */
+        move_it_to (&it, disp_string_at_start_p ? PT - 1 : PT,
+                    -1, -1, -1, MOVE_TO_POS);
 
       /* IT may move too far if truncate-lines is on and PT lies
          beyond the right margin.  IT may also move too far if the