[TEST] Forbid reentering ScriptLoader::prepareScript()

third_party/WebKit/Source/core/dom/ScriptLoader.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) 2003, 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights
  * reserved.
  * Copyright (C) 2008 Nikolas Zimmermann <zimmermann@kde.org>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 184 matching lines @@
 bool ScriptLoader::isScriptTypeSupported(
     LegacyTypeSupport supportLegacyTypes) const {
   return isValidScriptTypeAndLanguage(client()->typeAttributeValue(),
                                       client()->languageAttributeValue(),
                                       supportLegacyTypes);
 }
 
 // http://dev.w3.org/html5/spec/Overview.html#prepare-a-script
 bool ScriptLoader::prepareScript(const TextPosition& scriptStartPosition,
                                  LegacyTypeSupport supportLegacyTypes) {
+  DCHECK(!m_inPrepareScript);
+  AutoReset<bool> inPrepareScriptScope(&m_inPrepareScript, true);
+
+  DCHECK(!m_willBeParserExecuted);
+  DCHECK(!m_willExecuteWhenDocumentFinishedParsing);
+  DCHECK(!m_readyToBeParserExecuted);
+
   if (m_alreadyStarted)
     return false;
 
   ScriptLoaderClient* client = this->client();
 
   bool wasParserInserted;
   if (m_parserInserted) {
     wasParserInserted = true;
     m_parserInserted = false;
   } else {
@@ skipping 429 matching lines @@
   if (isHTMLScriptLoader(element))
     return toHTMLScriptElement(element)->loader();
 
   if (isSVGScriptLoader(element))
     return toSVGScriptElement(element)->loader();
 
   return 0;
 }
 
 }  // namespace blink