applyXSLTransform is too eager

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 3886 matching lines @@
 }
 
 void Document::popCurrentScript()
 {
     ASSERT(!m_currentScriptStack.isEmpty());
     m_currentScriptStack.removeLast();
 }
 
 void Document::applyXSLTransform(ProcessingInstruction* pi)
 {
+    ASSERT(!pi->isLoading());
     UseCounter::count(this, UseCounter::XSLProcessingInstruction);
     RefPtr<XSLTProcessor> processor = XSLTProcessor::create();
     processor->setXSLStyleSheet(static_cast<XSLStyleSheet*>(pi->sheet()));
     String resultMIMEType;
     String newSource;
     String resultEncoding;
     if (!processor->transformToString(this, resultMIMEType, newSource, resultEncoding))
         return;
     // FIXME: If the transform failed we should probably report an error (like Mozilla does).
     Frame* ownerFrame = frame();
@@ skipping 1169 matching lines @@
 {
     return DocumentLifecycleNotifier::create(this);
 }
 
 DocumentLifecycleNotifier* Document::lifecycleNotifier()
 {
     return static_cast<DocumentLifecycleNotifier*>(ScriptExecutionContext::lifecycleNotifier());
 }
 
 } // namespace WebCore