From c6a14440faac0b3293a8457025f890f5016400ea Mon Sep 17 00:00:00 2001
From: "marco.zehe@googlemail.com" <none@none>
Date: Thu, 24 Apr 2008 23:34:02 -0700
Subject: [PATCH] bug 429617 - Crash [@ nsAccessNode::ClearCacheEntry(void
 const*, nsCOMPtr<nsIAccessNode>&, void*) ] r=surkov a1.9=beltzner

---
 accessible/src/base/nsAccessNode.cpp | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/accessible/src/base/nsAccessNode.cpp b/accessible/src/base/nsAccessNode.cpp
index fcd756a9a6d..eb69339ed2a 100755
--- a/accessible/src/base/nsAccessNode.cpp
+++ b/accessible/src/base/nsAccessNode.cpp
@@ -794,8 +794,11 @@ nsAccessNode::GetCacheEntry(nsAccessNodeHashtable& aCache,
 
 PLDHashOperator nsAccessNode::ClearCacheEntry(const void* aKey, nsCOMPtr<nsIAccessNode>& aAccessNode, void* aUserArg)
 {
-  nsCOMPtr<nsPIAccessNode> privateAccessNode(do_QueryInterface(aAccessNode));
-  privateAccessNode->Shutdown();
+  NS_ASSERTION(!aAccessNode, "Calling ClearCacheEntry with a NULL pointer!");
+  if (aAccessNode) {
+    nsCOMPtr<nsPIAccessNode> privateAccessNode(do_QueryInterface(aAccessNode));
+    privateAccessNode->Shutdown();
+  }
 
   return PL_DHASH_REMOVE;
 }