Fix bug #17539 with infinite recursion during scroll commands.

 src/xdisp.c (move_it_in_display_line_to): Avoid infinite recursion:
 when closest_pos is identical to to_charpos, don't recurse, since
 we already tried that, and failed.

2 files changed, 17 insertions, 5 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index cb54bbd0e70..1e6bdcb4999 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,9 @@
+2014-05-21  Eli Zaretskii  <eliz@gnu.org>
+
+        * xdisp.c (move_it_in_display_line_to): Avoid infinite recursion:
+        when closest_pos is identical to to_charpos, don't recurse, since
+        we already tried that, and failed.  (Bug#17539)
+
 2014-05-20  Eli Zaretskii  <eliz@gnu.org>
 
         * w32fns.c (unwind_create_frame) [GLYPH_DEBUG]: If we are
diff --git a/src/xdisp.c b/src/xdisp.c
index 88d61a6bbc0..e9c3cb1aac6 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -8812,8 +8812,11 @@ move_it_in_display_line_to (struct it *it,
                   if (closest_pos < ZV)
                     {
                       RESTORE_IT (it, &ppos_it, ppos_data);
-                      move_it_in_display_line_to (it, closest_pos, -1,
-                                                  MOVE_TO_POS);
+                      /* Don't recurse if closest_pos is equal to
+                         to_charpos, since we have just tried that.  */
+                      if (closest_pos != to_charpos)
+                        move_it_in_display_line_to (it, closest_pos, -1,
+                                                    MOVE_TO_POS);
                       result = MOVE_POS_MATCH_OR_ZV;
                     }
                   else
@@ -8874,8 +8877,9 @@ move_it_in_display_line_to (struct it *it,
                       && !at_eob_p && closest_pos < ZV)
                     {
                       RESTORE_IT (it, &ppos_it, ppos_data);
-                      move_it_in_display_line_to (it, closest_pos, -1,
-                                                  MOVE_TO_POS);
+                      if (closest_pos != to_charpos)
+                        move_it_in_display_line_to (it, closest_pos, -1,
+                                                    MOVE_TO_POS);
                     }
                   result = MOVE_POS_MATCH_OR_ZV;
                   break;
@@ -8893,7 +8897,9 @@ move_it_in_display_line_to (struct it *it,
               if (closest_pos < ZV)
                 {
                   RESTORE_IT (it, &ppos_it, ppos_data);
-                  move_it_in_display_line_to (it, closest_pos, -1, MOVE_TO_POS);
+                  if (closest_pos != to_charpos)
+                    move_it_in_display_line_to (it, closest_pos, -1,
+                                                MOVE_TO_POS);
                 }
               result = MOVE_POS_MATCH_OR_ZV;
               break;