* window.c (grow_mini_window): Comment out "delta >= 0" assertion.

  For delta < 0, skip check that only makes sense when the mini-window
  is going to be enlarged.  (Bug#4534)

src/ChangeLog

+2009-10-26  Juanma Barranquero  <lekktu@gmail.com>
+
+	* window.c (grow_mini_window): Comment out "delta >= 0" assertion.
+	For delta < 0, skip check that only makes sense when the mini-window
+	is going to be enlarged.  (Bug#4534)
+
 2009-10-25  Chong Yidong  <cyd@stupidchicken.com>
 
 	* keyboard.c (read_char_x_menu_prompt): Don't demand a prompt
@@ -20,8 +26,7 @@
 	* lisp.h (FIXNUM_OVERFLOW_P): Fix last change to handle unsigned
 	types again.
 
-	* sysdep.c (procfs_ttyname): Fix sprintf format to match argument
-	type.
+	* sysdep.c (procfs_ttyname): Fix sprintf format to match argument type.
 	(system_process_attributes): Likewise.
 
 2009-10-24  Dan Nicolaescu  <dann@ics.uci.edu>

src/window.c

@@ -4648,12 +4648,15 @@ grow_mini_window (w, delta)
   struct window *root;
 
   xassert (MINI_WINDOW_P (w));
-  xassert (delta >= 0);
+  /* Commenting out the following assertion goes against the stated interface
+     of the function, but it currently does not seem to do anything useful.
+     See discussion of this issue in the thread for bug#4534.
+     xassert (delta >= 0); */
 
   /* Compute how much we can enlarge the mini-window without deleting
      other windows.  */
   root = XWINDOW (FRAME_ROOT_WINDOW (f));
-  if (delta)
+  if (delta > 0)
     {
       int min_height = window_min_size (root, 0, 0, 0, 0);
       if (XFASTINT (root->total_lines) - delta < min_height)