diff -U0 emacs-23.3/src/ChangeLog.wm-state-hidden emacs-23.3/src/ChangeLog
--- emacs-23.3/src/ChangeLog.wm-state-hidden	2011-03-07 06:08:03.000000000 +0100
+++ emacs-23.3/src/ChangeLog	2011-11-23 11:49:57.053019839 +0100
@@ -1,0 +2,13 @@
+2011-10-30  Jan Djärv  <jan.h.d@swipnet.se>
+
+	* xterm.h (x_display_info): Add Xatom_net_wm_state_hidden (Bug#9893).
+
+	* xterm.c: Declare x_handle_net_wm_state to return int.
+	(handle_one_xevent): Check if we are iconified but don't have
+	_NET_WM_STATE_HIDDEN.  If do, treat as deiconify (Bug#9893).
+	(get_current_wm_state): Return non-zero if not hidden,
+	check for _NET_WM_STATE_HIDDEN (Bug#9893).
+	(do_ewmh_fullscreen): Ignore return value from get_current_wm_state.
+	(x_handle_net_wm_state): Return what get_current_wm_state returns.
+	(x_term_init): Initialize dpyinfo->Xatom_net_wm_state_hidden.
+
diff -up emacs-23.3/src/xterm.c.wm-state-hidden emacs-23.3/src/xterm.c
--- emacs-23.3/src/xterm.c.wm-state-hidden	2011-02-12 01:27:01.000000000 +0100
+++ emacs-23.3/src/xterm.c	2011-11-23 11:55:10.867096378 +0100
@@ -375,7 +375,7 @@ static void x_scroll_bar_report_motion P
 					    enum scroll_bar_part *,
 					    Lisp_Object *, Lisp_Object *,
 					    unsigned long *));
-static void x_handle_net_wm_state P_ ((struct frame *, XPropertyEvent *));
+static int x_handle_net_wm_state P_ ((struct frame *, XPropertyEvent *));
 static void x_check_fullscreen P_ ((struct frame *));
 static void x_check_expected_move P_ ((struct frame *, int, int));
 static void x_sync_with_move P_ ((struct frame *, int, int, int));
@@ -6121,7 +6121,19 @@ handle_one_xevent (dpyinfo, eventp, fini
       last_user_time = event.xproperty.time;
       f = x_top_window_to_frame (dpyinfo, event.xproperty.window);
       if (f && event.xproperty.atom == dpyinfo->Xatom_net_wm_state)
-        x_handle_net_wm_state (f, &event.xproperty);
+        if (x_handle_net_wm_state (f, &event.xproperty) && f->iconified)
+          {
+            /* Gnome shell does not iconify us when C-z is pressed.  It hides
+               the frame.  So if our state says we aren't hidden anymore,
+               treat is as deiconfied.  */
+            if (! f->async_iconified)
+              SET_FRAME_GARBAGED (f);
+            f->async_visible = 1;
+            f->async_iconified = 0;
+            f->output_data.x->has_been_visible = 1;
+            inev.ie.kind = DEICONIFY_EVENT;
+            XSETFRAME (inev.ie.frame_or_window, f);
+          }
 
       x_handle_property_notify (&event.xproperty);
       xft_settings_event (dpyinfo, &event);
@@ -8573,9 +8585,10 @@ x_set_sticky (f, new_value, old_value)
 
 /* Return the current _NET_WM_STATE.
    SIZE_STATE is set to one of the FULLSCREEN_* values.
-   STICKY is set to 1 if the sticky state is set, 0 if not.  */
+   STICKY is set to 1 if the sticky state is set, 0 if not.
+   Return non-zero if we are not hidden, zero if we are.  */
 
-static void
+static int
 get_current_vm_state (struct frame *f,
                       Window window,
                       int *size_state,
@@ -8583,7 +8596,7 @@ get_current_vm_state (struct frame *f,
 {
   Atom actual_type;
   unsigned long actual_size, bytes_remaining;
-  int i, rc, actual_format;
+  int i, rc, actual_format, is_hidden = 0;
   struct x_display_info *dpyinfo = FRAME_X_DISPLAY_INFO (f);
   long max_len = 65536;
   Display *dpy = FRAME_X_DISPLAY (f);
@@ -8605,7 +8618,7 @@ get_current_vm_state (struct frame *f,
       if (tmp_data) XFree (tmp_data);
       x_uncatch_errors ();
       UNBLOCK_INPUT;
-      return;
+      return ! f->iconified;
     }
 
   x_uncatch_errors ();
@@ -8613,7 +8626,9 @@ get_current_vm_state (struct frame *f,
   for (i = 0; i < actual_size; ++i)
     {
       Atom a = ((Atom*)tmp_data)[i];
-      if (a == dpyinfo->Xatom_net_wm_state_maximized_horz) 
+      if (a == dpyinfo->Xatom_net_wm_state_hidden)
+        is_hidden = 1;
+      else if (a == dpyinfo->Xatom_net_wm_state_maximized_horz)
         {
           if (*size_state == FULLSCREEN_HEIGHT)
             *size_state = FULLSCREEN_MAXIMIZED;
@@ -8635,6 +8650,7 @@ get_current_vm_state (struct frame *f,
 
   if (tmp_data) XFree (tmp_data);
   UNBLOCK_INPUT;
+  return ! is_hidden;
 }
 
 /* Do fullscreen as specified in extended window manager hints */
@@ -8647,7 +8663,7 @@ do_ewmh_fullscreen (f)
   Lisp_Object lval = get_frame_param (f, Qfullscreen);
   int cur, dummy;
 
-  get_current_vm_state (f, FRAME_OUTER_WINDOW (f), &cur, &dummy);
+  (void)get_current_vm_state (f, FRAME_OUTER_WINDOW (f), &cur, &dummy);
 
   /* Some window managers don't say they support _NET_WM_STATE, but they do say
      they support _NET_WM_STATE_FULLSCREEN.  Try that also.  */
@@ -8721,7 +8737,7 @@ XTfullscreen_hook (f)
 }
 
 
-static void
+static int
 x_handle_net_wm_state (f, event)
      struct frame *f;
      XPropertyEvent *event;
@@ -8729,10 +8745,10 @@ x_handle_net_wm_state (f, event)
   int value = FULLSCREEN_NONE;
   Lisp_Object lval;
   int sticky = 0;
+  int not_hidden = get_current_vm_state (f, event->window, &value, &sticky);
 
-  get_current_vm_state (f, event->window, &value, &sticky);
   lval = Qnil;
-  switch (value) 
+  switch (value)
     {
     case FULLSCREEN_WIDTH:
       lval = Qfullwidth;
@@ -8747,9 +8763,10 @@ x_handle_net_wm_state (f, event)
       lval = Qmaximized;
       break;
     }
-      
   store_frame_param (f, Qfullscreen, lval);
   store_frame_param (f, Qsticky, sticky ? Qt : Qnil);
+
+  return not_hidden;
 }
 
 /* Check if we need to resize the frame due to a fullscreen request.
@@ -9487,7 +9504,7 @@ x_iconify_frame (f)
   if (!NILP (type))
     x_bitmap_icon (f, type);
 
-#ifdef USE_GTK
+#if defined (USE_GTK)
   if (FRAME_GTK_OUTER_WIDGET (f))
     {
       if (! FRAME_VISIBLE_P (f))
@@ -10518,6 +10535,8 @@ x_term_init (display_name, xrm_option, r
     = XInternAtom (dpyinfo->display, "_NET_WM_STATE_MAXIMIZED_VERT", False);
   dpyinfo->Xatom_net_wm_state_sticky
     = XInternAtom (dpyinfo->display, "_NET_WM_STATE_STICKY", False);
+  dpyinfo->Xatom_net_wm_state_hidden
+    = XInternAtom (dpyinfo->display, "_NET_WM_STATE_HIDDEN", False);
   dpyinfo->Xatom_net_window_type
     = XInternAtom (dpyinfo->display, "_NET_WM_WINDOW_TYPE", False);
   dpyinfo->Xatom_net_window_type_tooltip
diff -up emacs-23.3/src/xterm.h.wm-state-hidden emacs-23.3/src/xterm.h
--- emacs-23.3/src/xterm.h.wm-state-hidden	2011-01-08 18:45:14.000000000 +0100
+++ emacs-23.3/src/xterm.h	2011-11-23 11:56:01.219467181 +0100
@@ -365,7 +365,7 @@ struct x_display_info
   /* Atoms dealing with EWMH (i.e. _NET_...) */
   Atom Xatom_net_wm_state, Xatom_net_wm_state_fullscreen_atom,
     Xatom_net_wm_state_maximized_horz, Xatom_net_wm_state_maximized_vert,
-    Xatom_net_wm_state_sticky, Xatom_net_frame_extents;
+    Xatom_net_wm_state_sticky, Xatom_net_wm_state_hidden, Xatom_net_frame_extents;
 
   /* XSettings atoms and windows.  */
   Atom Xatom_xsettings_sel, Xatom_xsettings_prop, Xatom_xsettings_mgr;