From 59565080becb95f4d47971d09ce126a5193d076e Mon Sep 17 00:00:00 2001
From: "caillon%returnzero.com" <caillon%returnzero.com>
Date: Sat, 17 May 2003 13:57:16 +0000
Subject: [PATCH] 205225 - document.createTreeWalker(null, ...) wasn't null
 checking. r=sicking sr=jst a=asa

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

diff --git a/content/base/src/nsDocument.cpp b/content/base/src/nsDocument.cpp
index 4379e9382b29..a29621fd27ff 100644
--- a/content/base/src/nsDocument.cpp
+++ b/content/base/src/nsDocument.cpp
@@ -2772,6 +2772,10 @@ nsDocument::CreateTreeWalker(nsIDOMNode *aRoot,
 {
   *_retval = nsnull;
 
+  if (!aRoot) {
+    return NS_ERROR_DOM_NOT_SUPPORTED_ERR;
+  }
+
   nsresult rv = nsContentUtils::CheckSameOrigin(this, aRoot);
   if (NS_FAILED(rv)) {
     return rv;