From 71edcafb0ebbce66d240c369c3b681425f7666d7 Mon Sep 17 00:00:00 2001
From: Ms2ger <ms2ger@gmail.com>
Date: Sun, 11 Mar 2012 09:48:16 +0100
Subject: [PATCH] Bug 649599 - Make getAttributeNS return null for absent
 attributes; r=peterv

---
 content/base/src/nsGenericElement.cpp                 | 11 ++++++-----
 .../dom-level2-core/test_getAttributeNS03.html        |  2 +-
 2 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/content/base/src/nsGenericElement.cpp b/content/base/src/nsGenericElement.cpp
index 88f1167a93d..51e5d9aad86 100644
--- a/content/base/src/nsGenericElement.cpp
+++ b/content/base/src/nsGenericElement.cpp
@@ -2853,15 +2853,16 @@ nsGenericElement::GetAttributeNS(const nsAString& aNamespaceURI,
     nsContentUtils::NameSpaceManager()->GetNameSpaceID(aNamespaceURI);
 
   if (nsid == kNameSpaceID_Unknown) {
-    // Unknown namespace means no attr...
-
-    aReturn.Truncate();
-
+    // Unknown namespace means no attribute.
+    SetDOMStringToNull(aReturn);
     return NS_OK;
   }
 
   nsCOMPtr<nsIAtom> name = do_GetAtom(aLocalName);
-  GetAttr(nsid, name, aReturn);
+  bool hasAttr = GetAttr(nsid, name, aReturn);
+  if (!hasAttr) {
+    SetDOMStringToNull(aReturn);
+  }
 
   return NS_OK;
 }
diff --git a/dom/tests/mochitest/dom-level2-core/test_getAttributeNS03.html b/dom/tests/mochitest/dom-level2-core/test_getAttributeNS03.html
index e9dfcb64e68..5a5a3359464 100644
--- a/dom/tests/mochitest/dom-level2-core/test_getAttributeNS03.html
+++ b/dom/tests/mochitest/dom-level2-core/test_getAttributeNS03.html
@@ -105,7 +105,7 @@ function getAttributeNS03() {
       assertNotNull("empAddrNotNull",testAddr);
 testAddr.removeAttributeNS(namespaceURI,localName);
       attrValue = testAddr.getAttributeNS(namespaceURI,localName);
-      assertEquals("throw_Equals","",attrValue);
+      assertEquals("throw_Equals",null,attrValue);
        
 }