createElementNS handles element name 'xmlns' correctly.

Source/core/dom/Document.cpp

Index: Source/core/dom/Document.cpp
diff --git a/Source/core/dom/Document.cpp b/Source/core/dom/Document.cpp
index b77d6563978e66f75a18593a7f7cd6d682e44252..c715c9f912077c0f3e17f22e6549a2c54e4daa2e 100644
--- a/Source/core/dom/Document.cpp
+++ b/Source/core/dom/Document.cpp
@@ -965,21 +965,14 @@ bool Document::hasValidNamespaceForElements(const QualifiedName& qName)
 
     // Required by DOM Level 3 Core and unspecified by DOM Level 2 Core:
     // http://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/core.html#ID-DocCrElNS
-    // createElementNS("http://www.w3.org/2000/xmlns/", "foo:bar"), createElementNS(null, "xmlns:bar")
-    if ((qName.prefix() == xmlnsAtom && qName.namespaceURI() != XMLNSNames::xmlnsNamespaceURI) || (qName.prefix() != xmlnsAtom && qName.namespaceURI() == XMLNSNames::xmlnsNamespaceURI))
-        return false;
-
-    return true;
+    // createElementNS("http://www.w3.org/2000/xmlns/", "foo:bar"), createElementNS(null, "xmlns:bar"), createElementNS(null, "xmlns")
+    if (qName.prefix() == xmlnsAtom || (qName.prefix().isEmpty() && qName.localName() == xmlnsAtom))
+        return qName.namespaceURI() == XMLNSNames::xmlnsNamespaceURI;
+    return qName.namespaceURI() != XMLNSNames::xmlnsNamespaceURI;
 }
 
 bool Document::hasValidNamespaceForAttributes(const QualifiedName& qName)
 {
-    // Spec: DOM Level 2 Core: http://www.w3.org/TR/DOM-Level-2-Core/core.html#ID-ElSetAttrNS
-    if (qName.prefix().isEmpty() && qName.localName() == xmlnsAtom) {
-        // Note: The case of an "xmlns" qualified name with a namespace of
-        // xmlnsNamespaceURI is specifically allowed (See <http://www.w3.org/2000/xmlns/>).
-        return qName.namespaceURI() == XMLNSNames::xmlnsNamespaceURI;
-    }
     return hasValidNamespaceForElements(qName);
 }