From b1179978f52c80a962f4be420246a9724b826e53 Mon Sep 17 00:00:00 2001
From: Robert Osfield <robert@openscenegraph.com>
Date: Wed, 12 May 2010 11:41:36 +0000
Subject: [PATCH] From Stephan Huber, "attached you'll find a fix for a crash
 when closeImplementation gets called more than once."

---
 src/osgViewer/PixelBufferCarbon.cpp | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/osgViewer/PixelBufferCarbon.cpp b/src/osgViewer/PixelBufferCarbon.cpp
index c995c3933..0e18de3b0 100644
--- a/src/osgViewer/PixelBufferCarbon.cpp
+++ b/src/osgViewer/PixelBufferCarbon.cpp
@@ -115,6 +115,11 @@ void  PixelBufferCarbon::closeImplementation()
     if (_pbuffer) aglDestroyPBuffer(_pbuffer);
     if (_context) aglDestroyContext(_context);
     if (_pixelformat) aglDestroyPixelFormat(_pixelformat);
+    
+    _pbuffer = NULL;
+    _context = NULL;
+    _pixelformat = NULL;
+    
     _valid = _realized = false;
 }