--- a/src/ChangeLog	Fri Oct 28 23:52:26 2011 +0900
+++ b/src/ChangeLog	Sat Oct 29 00:35:33 2011 +0900
@@ -1,3 +1,16 @@
+2011-10-29  Stephen J. Turnbull  <stephen@xemacs.org>
+
+	Prevent assert at frame.c, l. 6311 by initializing glyph cachels.
+
+	* frame.c (Fmake_frame): Ensure that reset_glyph_cachels gets called.
+	(setup_minibuffer_frame): Improve header comment.
+
+	* redisplay.c (redisplay_window): Update comment.
+	Remove code checking for uninitialized face_cachels and glyph_cachels.
+	Can't happen in theory, and guarded by asserts in practice.
+
+	* window.c (allocate_window): Update comment on reset_*_cachels.
+
 2011-10-09  Aidan Kehoe  <kehoea@parhasard.net>
 
 	* fns.c (remassoc_no_quit):

--- a/src/frame.c	Fri Oct 28 23:52:26 2011 +0900
+++ b/src/frame.c	Sat Oct 29 00:35:33 2011 +0900
@@ -793,7 +793,8 @@
     f->minibuffer_window = Qnil;
 }
 
-/* Make a frame containing only a minibuffer window.  */
+/* Make a frame containing only a minibuffer window.
+   The minibuffer window is also the root window.  */
 
 static void
 setup_minibuffer_frame (struct frame *f)
@@ -957,8 +958,12 @@
   if (initialized && !DEVICE_STREAM_P (d))
     {
       if (!NILP (f->minibuffer_window))
-	reset_face_cachels (XWINDOW (f->minibuffer_window));
+	{
+	  reset_face_cachels (XWINDOW (f->minibuffer_window));
+	  reset_glyph_cachels (XWINDOW (f->minibuffer_window));
+	}
       reset_face_cachels (XWINDOW (f->root_window));
+      reset_glyph_cachels (XWINDOW (f->root_window));
     }
 
   /* If no frames on this device formerly existed, say this is the

--- a/src/redisplay.c	Fri Oct 28 23:52:26 2011 +0900
+++ b/src/redisplay.c	Sat Oct 29 00:35:33 2011 +0900
@@ -6306,18 +6306,19 @@
      because we initialized them at startup and the only way to reduce
      their number is through calling reset_face_cachels() or
      reset_glyph_cachels(), which as a side effect sets up a number of
-     standard entries */
+     standard entries
+     2011-10-29 -- We were managing to hit the glyph_cachels assert in certain
+     contexts where VM was creating a lot of frames.  I don't have a full
+     analysis, but I suspect that we were failing to setup the glyph_cachels
+     at about l. 961 of frame.c, and a message was being sent to the echo area
+     before the initialization was complete.  This triggered a redisplay of
+     the minibuffer window (this part is confirmed), and thus this assert. */
   assert (Dynarr_length (w->face_cachels));
   assert (Dynarr_length (w->glyph_cachels));
 
   /* If the buffer has changed we have to invalidate all of our face
      cache elements. */
   if ((!echo_active && b != window_display_buffer (w))
-#if 0
-  /* #### Delete this code sometime later than 2-1-10 when we're sure it's
-     not needed */
-      || !Dynarr_length (w->face_cachels)
-#endif
       || f->faces_changed)
     reset_face_cachels (w);
   else
@@ -6327,11 +6328,6 @@
      the cache purely because glyphs have changed - this is now
      handled by the dirty flag.*/
   if ((!echo_active && b != window_display_buffer (w))
-#if 0
-  /* #### Delete this code sometime later than 2-1-10 when we're sure it's
-     not needed */
-      || !Dynarr_length (w->glyph_cachels)
-#endif
       || f->faces_changed)
     reset_glyph_cachels (w);
   else

--- a/src/window.c	Fri Oct 28 23:52:26 2011 +0900
+++ b/src/window.c	Sat Oct 29 00:35:33 2011 +0900
@@ -383,7 +383,10 @@
    All callers of allocate_window should therefore call
    reset_face_cachels on the created window.  We can't do it
    here because the window must have its frame pointer set or
-   reset_face_cachels will fail. */
+   reset_face_cachels will fail.
+   A similar requirement holds for reset_glyph_cachels.  We *could* do
+   that here (there's no reference to the frame pointer in that function),
+   but we may as well have the same discipline. */
 Lisp_Object
 allocate_window (void)
 {