From 2a923ad5471c00e19b1047b2a50b7174566e6646 Mon Sep 17 00:00:00 2001
From: "timeless@mozdev.org" <timeless@mozdev.org>
Date: Sat, 26 Mar 2011 00:39:12 -0400
Subject: [PATCH] Bug 620181 crash [@ nsXBLPrototypeBinding::LocateInstance] if
 the while loop condition becomes false r=neil

---
 content/xbl/src/nsXBLPrototypeBinding.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/content/xbl/src/nsXBLPrototypeBinding.cpp b/content/xbl/src/nsXBLPrototypeBinding.cpp
index 78f4043fa618..98c034085830 100644
--- a/content/xbl/src/nsXBLPrototypeBinding.cpp
+++ b/content/xbl/src/nsXBLPrototypeBinding.cpp
@@ -896,6 +896,10 @@ nsXBLPrototypeBinding::LocateInstance(nsIContent* aBoundElement,
       binding = binding->GetBaseBinding();
     }
 
+    NS_ABORT_IF_FALSE(binding, "Bug 620181 this is unexpected");
+    if (!binding)
+      return nsnull;
+
     nsInsertionPointList* points = nsnull;
     if (anonContent == copyParent)
       binding->GetInsertionPointsFor(aBoundElement, &points);