Fix bug #18584 with assertion violations while scrolling.

 src/xdisp.c (move_it_by_lines): Call reseat_1 after moving the
 iterator backwards, to resync the bidi iterator.

2 files changed, 6 insertions, 0 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 808a8f94c74..331da12aa13 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,8 @@
+2014-10-02  Eli Zaretskii  <eliz@gnu.org>
+
+        * xdisp.c (move_it_by_lines): Call reseat_1 after moving the
+        iterator backwards, to resync the bidi iterator.  (Bug#18584)
+
 2014-10-01  Jan Djärv  <jan.h.d@swipnet.se>
 
         * xfaces.c (Finternal_set_lisp_face_attribute): Don't try to
diff --git a/src/xdisp.c b/src/xdisp.c
index c68d1375ff7..80d4d52531a 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -9748,6 +9748,7 @@ move_it_by_lines (struct it *it, ptrdiff_t dvpos)
               back_to_previous_visible_line_start (it);
               it->vpos--;
             }
+          reseat_1 (it, it->current.pos, 1);
         }
       else
         RESTORE_IT (it, it, it2data);