2 files changed, 9 insertions, 0 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index d0d72dd6016..6dbaa5cbcf2 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,10 @@
+2014-01-24  Dmitry Antipov  <dmantipov@yandex.ru>
+
+        * xdisp.c (reseat_1, Fcurrent_bidi_paragraph_direction): Avoid
+        undefined behavior by initializing display property bit of a
+        string processed by the bidirectional iterator.  For details, see
+        <http://lists.gnu.org/archive/html/emacs-devel/2014-01/msg01920.html>.
+
 2014-01-23  Paul Eggert  <eggert@cs.ucla.edu>
 
         Minor cleanup of previous change.
diff --git a/src/xdisp.c b/src/xdisp.c
index bd6630a23c3..e59612696e9 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -6409,6 +6409,7 @@ reseat_1 (struct it *it, struct text_pos pos, int set_stop_p)
       it->bidi_it.string.s = NULL;
       it->bidi_it.string.lstring = Qnil;
       it->bidi_it.string.bufpos = 0;
+      it->bidi_it.string.from_disp_str = 0;
       it->bidi_it.string.unibyte = 0;
       it->bidi_it.w = it->w;
     }
@@ -20411,6 +20412,7 @@ See also `bidi-paragraph-direction'.  */)
       itb.string.s = NULL;
       itb.string.lstring = Qnil;
       itb.string.bufpos = 0;
+      itb.string.from_disp_str = 0;
       itb.string.unibyte = 0;
       /* We have no window to use here for ignoring window-specific
          overlays.  Using NULL for window pointer will cause