Make sure the rootNode of a LiveNodeListBase is always a ContainerNode

Source/core/dom/ChildNodeList.h

Index: Source/core/dom/ChildNodeList.h
diff --git a/Source/core/dom/ChildNodeList.h b/Source/core/dom/ChildNodeList.h
index 46f5beab4b15b00610e0711d120b3b1de6f9e35d..a83afd182ab27a6a37984b594d22053912ef137b 100644
--- a/Source/core/dom/ChildNodeList.h
+++ b/Source/core/dom/ChildNodeList.h
@@ -31,7 +31,7 @@ namespace WebCore {
 
 class ChildNodeList FINAL : public LiveNodeList {
 public:
-    static PassRefPtr<ChildNodeList> create(PassRefPtr<Node> rootNode)
+    static PassRefPtr<ChildNodeList> create(PassRefPtr<ContainerNode> rootNode)
     {
         return adoptRef(new ChildNodeList(rootNode));
     }
@@ -39,11 +39,33 @@ public:
     virtual ~ChildNodeList();
 
 protected:
-    explicit ChildNodeList(PassRefPtr<Node> rootNode);
+    explicit ChildNodeList(PassRefPtr<ContainerNode> rootNode);
 
     virtual bool nodeMatches(Element*) const OVERRIDE;
 };
 
+class EmptyNodeList FINAL : public NodeList {

[esprehn, 2014/01/17 07:06:20]

Please put this in its own file.

[Inactive, 2014/01/17 15:00:48]

Done.

+public:
+    static PassRefPtr<EmptyNodeList> create(Node* owner)
+    {
+        return adoptRef(new EmptyNodeList(owner));
+    }
+    virtual ~EmptyNodeList();
+
+    Node* ownerNode() const { return m_owner.get(); }
+
+private:
+    explicit EmptyNodeList(Node* owner) : m_owner(owner) { }
+
+    virtual unsigned length() const OVERRIDE { return 0; }
+    virtual Node* item(unsigned) const OVERRIDE { return 0; }
+    virtual Node* namedItem(const AtomicString&) const OVERRIDE { return 0; }
+
+    virtual bool isEmptyNodeList() const OVERRIDE { return true; }
+
+    RefPtr<Node> m_owner;
+};
+
 } // namespace WebCore
 
 #endif // ChildNodeList_h