diff --git a/menu/m_sub.c b/menu/m_sub.c
index 82649c5..37529a0 100644
--- a/menu/m_sub.c
+++ b/menu/m_sub.c
@@ -1,5 +1,5 @@
 /****************************************************************************
- * Copyright (c) 1998-2003,2004 Free Software Foundation, Inc.              *
+ * Copyright (c) 1998-2004,2010 Free Software Foundation, Inc.              *
  *                                                                          *
  * Permission is hereby granted, free of charge, to any person obtaining a  *
  * copy of this software and associated documentation files (the            *
@@ -37,7 +37,7 @@
 
 #include "menu.priv.h"
 
-MODULE_ID("$Id: m_sub.c,v 1.10 2004/12/25 21:38:31 tom Exp $")
+MODULE_ID("$Id: m_sub.c,v 1.12 2010/01/23 21:20:11 tom Exp $")
 
 /*---------------------------------------------------------------------------
 |   Facility      :  libnmenu  
@@ -51,14 +51,28 @@
 NCURSES_EXPORT(int)
 set_menu_sub(MENU * menu, WINDOW *win)
 {
-  T((T_CALLED("set_menu_sub(%p,%p)"), menu, win));
+  T((T_CALLED("set_menu_sub(%p,%p)"), (void *)menu, (void *)win));
 
   if (menu)
     {
       if (menu->status & _POSTED)
 	RETURN(E_POSTED);
-      menu->usersub = win;
-      _nc_Calculate_Item_Length_and_Width(menu);
+      else
+#if NCURSES_SP_FUNCS
+	{
+	  /* We ensure that usersub is never null. So even if a null
+	     WINDOW parameter is passed, we store the SCREENS stdscr.
+	     The only MENU that can have a null usersub is the static
+	     _nc_default_Menu.
+	   */
+	  SCREEN *sp = _nc_screen_of(menu->usersub);
+
+	  menu->usersub = win ? win : sp->_stdscr;
+	  _nc_Calculate_Item_Length_and_Width(menu);
+	}
+#else
+	menu->usersub = win;
+#endif
     }
   else
     _nc_Default_Menu.usersub = win;
@@ -68,7 +82,7 @@
 
 /*---------------------------------------------------------------------------
 |   Facility      :  libnmenu  
-|   Function      :  WINDOW *menu_sub(const MENU *menu)
+|   Function      :  WINDOW* menu_sub(const MENU *menu)
 |   
 |   Description   :  Returns a pointer to the subwindow of the menu
 |
@@ -79,7 +93,7 @@
 {
   const MENU *m = Normalize_Menu(menu);
 
-  T((T_CALLED("menu_sub(%p)"), menu));
+  T((T_CALLED("menu_sub(%p)"), (const void *)menu));
   returnWin(Get_Menu_Window(m));
 }