(Fset_buffer_modified_p): Set buffer's

prevent_redisplay_optimizations_p flag.

src/ChangeLog

 2001-01-16  Gerd Moellmann  <gerd@gnu.org>
 
+	* buffer.c (Fset_buffer_modified_p): Set buffer's
+	prevent_redisplay_optimizations_p flag.
+
 	* dispnew.c, callproc.c, fns.c, keyboard.c, process.c, sunfns.c,
 	* sysdep.c, vmsproc.c, xselect.c: Call
 	redisplay_preserve_echo_area with additional arg.

src/buffer.c

@@ -894,7 +894,10 @@ A non-nil FLAG means mark the buffer modified.")
   XSETBUFFER (buffer, current_buffer);
   window = Fget_buffer_window (buffer, Qt);
   if (WINDOWP (window))
-    update_mode_lines++;
+    {
+      ++update_mode_lines;
+      current_buffer->prevent_redisplay_optimizations_p = 1;
+    }
   
   return flag;
 }