Stop handling the case where oldDocument and newDocument are the same in adoptDocument()

Source/core/dom/TreeScopeAdopter.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/)
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 64 matching lines @@
             if (willMoveToNewDocument)
                 moveTreeToNewDocument(*shadow, oldDocument, newDocument);
         }
     }
 
     m_oldScope.guardDeref();
 }
 
 void TreeScopeAdopter::moveTreeToNewDocument(Node& root, Document& oldDocument, Document& newDocument) const
 {
+    ASSERT(oldDocument != newDocument);
     for (Node* node = &root; node; node = NodeTraversal::next(*node, &root)) {
         moveNodeToNewDocument(*node, oldDocument, newDocument);
         for (ShadowRoot* shadow = node->youngestShadowRoot(); shadow; shadow = shadow->olderShadowRoot())
             moveTreeToNewDocument(*shadow, oldDocument, newDocument);
     }
 }
 
 #ifndef NDEBUG
 static bool didMoveToNewDocumentWasCalled = false;
 static Document* oldDocumentDidMoveToNewDocumentWasCalledWith = 0;
@@ skipping 10 matching lines @@
 {
     ASSERT(!node.isTreeScope());
     ASSERT(node.treeScope() == m_oldScope);
     m_newScope.guardRef();
     m_oldScope.guardDeref();
     node.setTreeScope(&m_newScope);
 }
 
 inline void TreeScopeAdopter::moveNodeToNewDocument(Node& node, Document& oldDocument, Document& newDocument) const
 {
-    ASSERT(!node.inDocument() || oldDocument != newDocument);
+    ASSERT(oldDocument != newDocument);
 
     if (node.hasRareData()) {
         NodeRareData* rareData = node.rareData();
         if (rareData->nodeLists())
             rareData->nodeLists()->adoptDocument(oldDocument, newDocument);
     }
 
     oldDocument.moveNodeIteratorsToNewDocument(node, newDocument);
 
     if (node.isShadowRoot())
         toShadowRoot(node).setDocument(newDocument);
 
 #ifndef NDEBUG
     didMoveToNewDocumentWasCalled = false;
     oldDocumentDidMoveToNewDocumentWasCalledWith = &oldDocument;
 #endif
 
     node.didMoveToNewDocument(oldDocument);
     ASSERT(didMoveToNewDocumentWasCalled);
 }
 
 }