(record_point): Don't call Fundo_boundary for first

change.  (Bug#731)

2 files changed, 12 insertions, 1 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index c53dd35e2d2..e2505f5dfb7 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,8 @@
+2008-09-22  Martin Rudalics  <rudalics@gmx.at>
+
+        * undo.c (record_point): Don't call Fundo_boundary for first
+        change.  (Bug#731)
+
 2008-09-22  Juanma Barranquero  <lekktu@gmail.com>
 
         * emacs.c (Fdaemonp): Doc fix.
diff --git a/src/undo.c b/src/undo.c
index 63daf1fdb68..d29ba17fde5 100644
--- a/src/undo.c
+++ b/src/undo.c
@@ -79,7 +79,13 @@ record_point (pt)
   if (NILP (pending_boundary))
     pending_boundary = Fcons (Qnil, Qnil);
 
-  if (current_buffer != last_undo_buffer)
+  if ((current_buffer != last_undo_buffer)
+      /* Don't call Fundo_boundary for the first change.  Otherwise we
+         risk overwriting last_boundary_position in Fundo_boundary with
+         PT of the current buffer and as a consequence not insert an
+         undo boundary because last_boundary_position will equal pt in
+         the test at the end of the present function (Bug#731).  */
+      && (MODIFF > SAVE_MODIFF))
     Fundo_boundary ();
   last_undo_buffer = current_buffer;