[Emacs-diffs] /srv/bzr/emacs/emacs-23 r100267: Avoid infloop when scrolling conservatively (Bug#7537).

[Chong Yidong]

------------------------------------------------------------
revno: 100267
committer: Chong Yidong <address@hidden>
branch nick: emacs-23
timestamp: Sat 2010-12-04 19:32:32 -0500
message:
  Avoid infloop when scrolling conservatively (Bug#7537).
  
  * src/xdisp.c (try_scrolling): Avoid infloop if the first line is obscured
  due to a vscroll (Bug#7537).
modified:
  src/ChangeLog
  src/xdisp.c

=== modified file 'src/ChangeLog'
--- a/src/ChangeLog     2010-12-02 07:12:54 +0000
+++ b/src/ChangeLog     2010-12-05 00:32:32 +0000
@@ -1,3 +1,8 @@
+2010-12-05  Chong Yidong  <address@hidden>
+
+       * xdisp.c (try_scrolling): Avoid infloop if the first line is
+       obscured due to a vscroll (Bug#7537).
+
 2010-12-02  Jan Djärv  <address@hidden>
 
        * nsterm.h (FRAME_NS_TOOLBAR_HEIGHT): Rename to FRAME_TOOLBAR_HEIGHT.

=== modified file 'src/xdisp.c'
--- a/src/xdisp.c       2010-11-04 19:35:32 +0000
+++ b/src/xdisp.c       2010-12-05 00:32:32 +0000
@@ -12759,7 +12759,11 @@
 
       /* If cursor ends up on a partially visible line,
         treat that as being off the bottom of the screen.  */
-      if (! cursor_row_fully_visible_p (w, extra_scroll_margin_lines <= 1, 0))
+      if (! cursor_row_fully_visible_p (w, extra_scroll_margin_lines <= 1, 0)
+         /* It's possible that the cursor is on the first line of the
+            buffer, which is partially obscured due to a vscroll
+            (Bug#7537).  In that case, avoid looping forever . */
+         && extra_scroll_margin_lines < w->desired_matrix->nrows - 1)
        {
          clear_glyph_matrix (w->desired_matrix);
          ++extra_scroll_margin_lines;