Reland r165040 "Make ancestors of modal <dialog> inert"

Source/core/dom/Node.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 774 matching lines @@
 
 bool Node::shouldHaveFocusAppearance() const
 {
     ASSERT(focused());
     return true;
 }
 
 bool Node::isInert() const
 {
     const HTMLDialogElement* dialog = document().activeModalDialog();
-    if (dialog && !containsIncludingShadowDOM(dialog) && !dialog->containsIncludingShadowDOM(this))
+    if (dialog && this != document() && !dialog->containsIncludingShadowDOM(this))
         return true;
     return document().ownerElement() && document().ownerElement()->isInert();
 }
 
 unsigned Node::nodeIndex() const
 {
     Node *_tempNode = previousSibling();
     unsigned count=0;
     for ( count=0; _tempNode; count++ )
         _tempNode = _tempNode->previousSibling();
@@ skipping 1835 matching lines @@
         node->showTreeForThis();
 }
 
 void showNodePath(const WebCore::Node* node)
 {
     if (node)
         node->showNodePathForThis();
 }
 
 #endif