From 61fb0026775c678c395366d67376ca32a73952d3 Mon Sep 17 00:00:00 2001
From: David Rose <david@ddrose.com>
Date: Thu, 12 Feb 2004 16:36:02 +0000
Subject: [PATCH] fix assertion error on window close

---
 panda/src/display/graphicsWindow.cxx | 1 +
 1 file changed, 1 insertion(+)

diff --git a/panda/src/display/graphicsWindow.cxx b/panda/src/display/graphicsWindow.cxx
index acf339f79a..19c0f9fa4e 100644
--- a/panda/src/display/graphicsWindow.cxx
+++ b/panda/src/display/graphicsWindow.cxx
@@ -547,6 +547,7 @@ void GraphicsWindow::
 close_window() {
   display_cat.info()
     << "Closing " << get_type() << "\n";
+  _is_valid = false;
 }
 
 ////////////////////////////////////////////////////////////////////