CSSStyleSheet::insertRule should respect the default namespace

Source/core/css/StyleSheetContents.cpp

 /*
  * (C) 1999-2003 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2006, 2007, 2012 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 42 matching lines @@
     for (unsigned i = 0; i < m_importRules.size(); ++i) {
         if (StyleSheetContents* sheet = m_importRules[i]->styleSheet())
             size += sheet->estimatedSizeInBytes();
     }
     return size;
 }
 
 StyleSheetContents::StyleSheetContents(StyleRuleImport* ownerRule, const String& originalURL, const CSSParserContext& context)
     : m_ownerRule(ownerRule)
     , m_originalURL(originalURL)
+    , m_defaultNamespace(starAtom)
     , m_hasSyntacticallyValidCSSHeader(true)
     , m_didLoadErrorOccur(false)
     , m_isMutable(false)
     , m_isInMemoryCache(false)
     , m_hasFontFaceRule(false)
     , m_hasMediaQueries(false)
     , m_hasSingleOwnerDocument(true)
     , m_parserContext(context)
 {
 }
 
 StyleSheetContents::StyleSheetContents(const StyleSheetContents& o)
     : m_ownerRule(nullptr)
     , m_originalURL(o.m_originalURL)
     , m_importRules(o.m_importRules.size())
     , m_childRules(o.m_childRules.size())
     , m_namespaces(o.m_namespaces)
+    , m_defaultNamespace(o.m_defaultNamespace)
     , m_hasSyntacticallyValidCSSHeader(o.m_hasSyntacticallyValidCSSHeader)
     , m_didLoadErrorOccur(false)
     , m_isMutable(false)
     , m_isInMemoryCache(false)
     , m_hasFontFaceRule(o.m_hasFontFaceRule)
     , m_hasMediaQueries(o.m_hasMediaQueries)
     , m_hasSingleOwnerDocument(true)
     , m_parserContext(o.m_parserContext)
 {
     ASSERT(o.isCacheable());
@@ skipping 161 matching lines @@
     }
     index -= m_importRules.size();
 
     if (m_childRules[index]->isFontFaceRule())
         notifyRemoveFontFaceRule(toStyleRuleFontFace(m_childRules[index].get()));
     m_childRules.remove(index);
 }
 
 void StyleSheetContents::parserAddNamespace(const AtomicString& prefix, const AtomicString& uri)
 {
-    if (uri.isNull() || prefix.isNull())
+    ASSERT(!uri.isNull());
+    if (prefix.isNull()) {
+        m_defaultNamespace = uri;
         return;
+    }
     PrefixNamespaceURIMap::AddResult result = m_namespaces.add(prefix, uri);
     if (result.isNewEntry)
         return;
     result.storedValue->value = uri;
 }
 
 const AtomicString& StyleSheetContents::determineNamespace(const AtomicString& prefix)
 {
     if (prefix.isNull())
         return nullAtom; // No namespace. If an element/attribute has a namespace, we won't match it.
@@ skipping 352 matching lines @@
     visitor->trace(m_ownerRule);
     visitor->trace(m_importRules);
     visitor->trace(m_childRules);
     visitor->trace(m_loadingClients);
     visitor->trace(m_completedClients);
     visitor->trace(m_ruleSet);
 #endif
 }
 
 }