From 364337083f18dece198baa79616c2610333c9c8a Mon Sep 17 00:00:00 2001
From: Luke Campagnola <>
Date: Mon, 18 Jun 2012 14:01:51 -0400
Subject: [PATCH] Added workaround for Qt crash-at-exit bug (make sure that all
 GraphicsItems live in a scene before exiting)

---
 __init__.py | 24 ++++++++++++++++++++----
 1 file changed, 20 insertions(+), 4 deletions(-)

diff --git a/__init__.py b/__init__.py
index e968d355..4c768a54 100644
--- a/__init__.py
+++ b/__init__.py
@@ -119,11 +119,27 @@ from .SignalProxy import *
 from .ptime import time
 
 
+## Workaround for Qt exit crash:
+## ALL QGraphicsItems must have a scene before they are deleted.
+## This is potentially very expensive, but preferred over crashing.
+import atexit
+def cleanup():
+    if QtGui.QApplication.instance() is None:
+        return
+    import gc
+    s = QtGui.QGraphicsScene()
+    for o in gc.get_objects():
+        try:
+            if isinstance(o, QtGui.QGraphicsItem) and o.scene() is None:
+                s.addItem(o)
+        except RuntimeError:  ## occurs if a python wrapper no longer has its underlying C++ object
+            continue
+atexit.register(cleanup)
+
+
 
 ## Convenience functions for command-line use
 
-
-
 plots = []
 images = []
 QAPP = None
@@ -176,8 +192,8 @@ show = image  ## for backward compatibility
     
     
 def mkQApp():
+    global QAPP
     if QtGui.QApplication.instance() is None:
-        global QAPP
         QAPP = QtGui.QApplication([])
-        
+    return QAPP