Implement cloneNode for Document

Source/core/dom/Document.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2008, 2009, 2011, 2012 Google Inc. All rights reserved.
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) Research In Motion Limited 2010-2011. All rights reserved.
@@ skipping 3072 matching lines @@
             break;
         }
     }
 
     if (numElements > 1 || numDoctypes > 1)
         return false;
 
     return true;
 }
 
-PassRefPtr<Node> Document::cloneNode(bool /*deep*/)
+PassRefPtr<Node> Document::cloneNode(bool deep)
 {
-    // Spec says cloning Document nodes is "implementation dependent"
-    // so we do not support it...
-    return 0;
+    RefPtr<Document> clone = cloneDocumentWithoutChildren();
+    clone->cloneDataFromDocument(*this);
+    if (deep)
+        cloneChildNodes(clone.get());
+    return clone.release();
+}
+
+PassRefPtr<Document> Document::cloneDocumentWithoutChildren()
+{
+    DocumentInit init(url());
+    if (isXHTMLDocument())
+        return createXHTML(init.withRegistrationContext(registrationContext()));
+    return create(init);
+}
+
+void Document::cloneDataFromDocument(const Document& other)
+{
+    setCompatibilityMode(other.compatibilityMode());
+    setSecurityOrigin(other.securityOrigin());

[abarth-chromium, 2013/08/26 21:04:55]

You should make a copy of the security origin.  The security origin object is
mutable, which means mutations will affect both documents.

+    setContextFeatures(other.contextFeatures());
+
+    setDecoder(TextResourceDecoder::create(other.suggestedMIMEType(), other.encoding()));

[abarth-chromium, 2013/08/26 21:04:55]

This doesn't make a lot of sense...  There is no text resource to decode.

jamesr is in the process of removing the TextResourceDecoder member from
Document, which will make this easier.

What about the HTMLImports state?  How do we decide which state to clone here?

[jamesr, 2013/08/26 21:07:51]

Have you tested that the exposed encoding on the new document should match the
old one?  If so, then we just need to call setEncoding(other.encoding()) once
https://codereview.chromium.org/22909053/ lands.  I'm not sure that makes sense,
though, since the cloned document wasn't generated by decoding an encoded
resource.

 }
 
 StyleSheetList* Document::styleSheets()
 {
     if (!m_styleSheetList)
         m_styleSheetList = StyleSheetList::create(this);
     return m_styleSheetList.get();
 }
 
 String Document::preferredStylesheetSet() const
@@ skipping 2137 matching lines @@
 {
     return DocumentLifecycleNotifier::create(this);
 }
 
 DocumentLifecycleNotifier* Document::lifecycleNotifier()
 {
     return static_cast<DocumentLifecycleNotifier*>(ScriptExecutionContext::lifecycleNotifier());
 }
 
 } // namespace WebCore