Backport Bug#9990 fix from trunk

* src/dispnew.c (scrolling_window): Fix incorrect indices in accessing
current_matrix and desired_matrix.  (Bug#9990)

2 files changed, 9 insertions, 4 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index d006f58b8b6..55cc8e8bf27 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,8 @@
+2012-01-09  Eli Zaretskii  <eliz@gnu.org>
+
+        * dispnew.c (scrolling_window): Fix incorrect indices in accessing
+        current_matrix and desired_matrix.  (Bug#9990)
+
 2011-10-31  YAMAMOTO Mitsuharu  <mituharu@math.s.chiba-u.ac.jp>
 
         * xmenu.c (cleanup_widget_value_tree): New function.
diff --git a/src/dispnew.c b/src/dispnew.c
index d2878a4fa57..c116c3f7c47 100644
--- a/src/dispnew.c
+++ b/src/dispnew.c
@@ -5035,10 +5035,10 @@ scrolling_window (w, header_line_p)
   j = last_old;
   while (i - 1 > first_new
          && j - 1 > first_old
-         && MATRIX_ROW (current_matrix, i - 1)->enabled_p
-         && (MATRIX_ROW (current_matrix, i - 1)->y
-             == MATRIX_ROW (desired_matrix, j - 1)->y)
-         && !MATRIX_ROW (desired_matrix, j - 1)->redraw_fringe_bitmaps_p
+         && MATRIX_ROW (current_matrix, j - 1)->enabled_p
+         && (MATRIX_ROW (current_matrix, j - 1)->y
+             == MATRIX_ROW (desired_matrix, i - 1)->y)
+         && !MATRIX_ROW (desired_matrix, i - 1)->redraw_fringe_bitmaps_p
          && row_equal_p (w,
                          MATRIX_ROW (desired_matrix, i - 1),
                          MATRIX_ROW (current_matrix, j - 1), 1))