user32: Reimplement IsHungAppWindow.
diff --git a/server/protocol.def b/server/protocol.def
index aa10f89..bfd7242 100644
--- a/server/protocol.def
+++ b/server/protocol.def
@@ -1925,6 +1925,14 @@
 @END
 
 
+/* check if the thread owning the window is hung */
+@REQ(is_window_hung)
+    user_handle_t   win;       /* window handle */
+@REPLY
+    int is_hung;
+@END
+
+
 /* Retrieve info about a serial port */
 @REQ(get_serial_info)
     obj_handle_t handle;       /* handle to comm port */