[Emacs-diffs] emacs-24 r117381: Fix bug #18036 with infloop in redisplay with huge fringes.

[Eli Zaretskii]

------------------------------------------------------------
revno: 117381
revision-id: address@hidden
parent: address@hidden
fixes bug: http://debbugs.gnu.org/18036
committer: Eli Zaretskii <address@hidden>
branch nick: emacs-24
timestamp: Wed 2014-07-16 21:39:35 +0300
message:
  Fix bug #18036 with infloop in redisplay with huge fringes.
  
   src/xdisp.c (move_it_vertically_backward, move_it_by_lines): Prevent
   infinite looping in redisplay when display lines don't have enough
   space to display even a single character.
modified:
  src/ChangeLog                  changelog-20091113204419-o5vbwnq5f7feedwu-1438
  src/xdisp.c                    xdisp.c-20091113204419-o5vbwnq5f7feedwu-240

=== modified file 'src/ChangeLog'
--- a/src/ChangeLog     2014-07-13 14:49:59 +0000
+++ b/src/ChangeLog     2014-07-16 18:39:35 +0000
@@ -1,3 +1,9 @@
+2014-07-16  Eli Zaretskii  <address@hidden>
+
+       * xdisp.c (move_it_vertically_backward, move_it_by_lines): Prevent
+       infinite looping in redisplay when display lines don't have enough
+       space to display even a single character.  (Bug#18036)
+
 2014-07-13  Eli Zaretskii  <address@hidden>
 
        * xdisp.c (decode_mode_spec): Call file-remote-p on the current

=== modified file 'src/xdisp.c'
--- a/src/xdisp.c       2014-07-13 14:49:59 +0000
+++ b/src/xdisp.c       2014-07-16 18:39:35 +0000
@@ -9351,7 +9351,7 @@
 
   /* Estimate how many newlines we must move back.  */
   nlines = max (1, dy / default_line_pixel_height (it->w));
-  if (it->line_wrap == TRUNCATE)
+  if (it->line_wrap == TRUNCATE || nchars_per_row == 0)
     pos_limit = BEGV;
   else
     pos_limit = max (start_pos - nlines * nchars_per_row, BEGV);
@@ -9606,7 +9606,7 @@
       /* Go back -DVPOS buffer lines, but no farther than -DVPOS full
         screen lines, and reseat the iterator there.  */
       start_charpos = IT_CHARPOS (*it);
-      if (it->line_wrap == TRUNCATE)
+      if (it->line_wrap == TRUNCATE || nchars_per_row == 0)
        pos_limit = BEGV;
       else
        pos_limit = max (start_charpos + dvpos * nchars_per_row, BEGV);