* window.c (Fdelete_window): Check WINDOW argument. (Bug#4618)

src/ChangeLog

@@ -1,3 +1,7 @@
+2009-10-03  Martin Rudalics  <rudalics@gmx.at>
+
+	* window.c (Fdelete_window): Check WINDOW argument.  (Bug#4618)
+
 2009-10-02  Michael Albinus  <michael.albinus@gmx.de>
 
 	* lisp.h (Qdelete_directory_internal): Removed, because it is not

src/window.c

@@ -1533,6 +1533,9 @@ Signal an error when WINDOW is the only window on its frame.  */)
   struct frame *f;
   if (NILP (window))
     window = selected_window;
+  else
+    CHECK_LIVE_WINDOW (window);
+
   f = XFRAME (WINDOW_FRAME (XWINDOW (window)));
   delete_window (window);