2 files changed, 7 insertions, 0 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 4226e20fd1b..7c5c49ccf3e 100644
--- a/src/ChangeLog
+++ b/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
diff --git a/src/window.c b/src/window.c
index 08fd8c829fa..9b50a85b0ca 100644
--- a/src/window.c
+++ b/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);