From 7c3b7b91f6b0799b851f5aa27f73a1da3b7a6e69 Mon Sep 17 00:00:00 2001
From: Kris Maglione <maglione.k@gmail.com>
Date: Sun, 24 Mar 2013 13:23:31 -0700
Subject: [PATCH] Fix bug.

---
 common/modules/sanitizer.jsm | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/common/modules/sanitizer.jsm b/common/modules/sanitizer.jsm
index 35220dda..a928fff1 100644
--- a/common/modules/sanitizer.jsm
+++ b/common/modules/sanitizer.jsm
@@ -301,7 +301,7 @@ var Sanitizer = Module("sanitizer", XPCOM([Ci.nsIObserver, Ci.nsISupportsWeakRef
         if (!Ci.nsILoadContext)
             return null;
 
-        if (thing instanceof Ci.nsIDOMNode)
+        if (thing instanceof Ci.nsIDOMNode && thing.ownerDocument)
             thing = thing.ownerDocument;
         if (thing instanceof Ci.nsIDOMDocument)
             thing = thing.defaultView;