1 files changed, 30 insertions, 2 deletions

diff --git a/Source/WebCore/dom/Document.h b/Source/WebCore/dom/Document.h
index b63618492..2014dcd84 100644
--- a/Source/WebCore/dom/Document.h
+++ b/Source/WebCore/dom/Document.h
@@ -1539,20 +1539,48 @@ private:
 
 // Put these methods here, because they require the Document definition, but we really want to inline them.
 
+inline TreeScope* Node::treeScope() const
+{
+    return m_treeScope == TreeScope::nullInstance() ? 0 : m_treeScope;
+}
+
+inline void Node::setTreeScope(TreeScope* scope)
+{
+    m_treeScope = scope ? scope : TreeScope::nullInstance();
+    setFlag(!m_treeScope->isDocumentScope(), InShadowTree);
+}
+
+inline Document* Node::documentInternal() const
+{
+    if (getFlag(InShadowTree))
+        return m_treeScope->rootDocument();
+    return static_cast<Document*>(m_treeScope);
+}
+
+inline Document* Node::document() const
+{
+    Document* document = documentInternal();
+    // FIXME: below ASSERT is useful, but prevents the use of document() in the constructor or destructor
+    // due to the virtual function call to nodeType().
+    ASSERT(document || (nodeType() == DOCUMENT_TYPE_NODE && !inDocument()));
+    return document;
+}
+
 inline bool Node::isDocumentNode() const
 {
-    return this == m_document;
+    return this == documentInternal();
 }
 
 inline Node::Node(Document* document, ConstructionType type)
     : m_nodeFlags(type)
-    , m_document(document)
+    , m_treeScope(0)
     , m_previous(0)
     , m_next(0)
     , m_renderer(0)
 {
     if (document)
         document->guardRef();
+    setTreeScope(document);
 #if !defined(NDEBUG) || (defined(DUMP_NODE_STATISTICS) && DUMP_NODE_STATISTICS)
     trackForDebugging();
 #endif