Fix random crashes while scrolling backwards.

 src/xdisp.c (try_cursor_movement): Make sure ROW isn't decremented
 past the beginning of the current glyph matrix.

2 files changed, 7 insertions, 3 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 9f8fa94d481..0bb16514b58 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,8 @@
+2011-10-30  Eli Zaretskii  <eliz@gnu.org>
+
+        * xdisp.c (try_cursor_movement): Make sure ROW isn't decremented
+        past the beginning of the current glyph matrix.
+
 2011-10-30  Adam Sjøgren <asjo@koldfront.dk> (tiny change)
 
         * xterm.c: Include X11/Xproto.h if HAVE_GTK3.
diff --git a/src/xdisp.c b/src/xdisp.c
index 22f7c2bbd26..33c5fc0d230 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -14829,8 +14829,6 @@ try_cursor_movement (Lisp_Object window, struct text_pos startp, int *scroll_ste
                  bidi-reordered rows.  */
               while (MATRIX_ROW_CONTINUATION_LINE_P (row))
                 {
-                  xassert (row->enabled_p);
-                  --row;
                   /* If we hit the beginning of the displayed portion
                      without finding the first row of a continued
                      line, give up.  */
@@ -14839,7 +14837,8 @@ try_cursor_movement (Lisp_Object window, struct text_pos startp, int *scroll_ste
                       rc = CURSOR_MOVEMENT_MUST_SCROLL;
                       break;
                     }
-
+                  xassert (row->enabled_p);
+                  --row;
                 }
             }
           if (must_scroll)