Throw DOM exception in insertAdjacentHTML if context becomes null

Source/core/html/HTMLElement.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2011 Motorola Mobility. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 488 matching lines @@
     if (!newChild) {
         // IE throws COM Exception E_INVALIDARG; this is the best DOM exception alternative.
         exceptionState.throwTypeError("The node provided is null.");
         return 0;
     }
 
     Node* returnValue = insertAdjacent(where, newChild, exceptionState);
     return toElement(returnValue);
 }
 
-// Step 3 of http://www.whatwg.org/specs/web-apps/current-work/multipage/apis-in-html-documents.html#insertadjacenthtml()
+// Step 1 of http://domparsing.spec.whatwg.org/#insertadjacenthtml()
 static Element* contextElementForInsertion(const String& where, Element* element, ExceptionState& exceptionState)
 {
     if (equalIgnoringCase(where, "beforeBegin") || equalIgnoringCase(where, "afterEnd")) {
         ContainerNode* parent = element->parentNode();
-        if (parent && !parent->isElementNode()) {
+        if (!parent || !parent->isElementNode()) {
             exceptionState.throwDOMException(NoModificationAllowedError, "The element has no parent.");
             return 0;
         }
         return toElement(parent);
     }
     if (equalIgnoringCase(where, "afterBegin") || equalIgnoringCase(where, "beforeEnd"))
         return element;
     exceptionState.throwDOMException(SyntaxError, "The value provided ('" + where + "') is not one of 'beforeBegin', 'afterBegin', 'beforeEnd', or 'afterEnd'.");
     return 0;
 }
@@ skipping 550 matching lines @@
 #ifndef NDEBUG
 
 // For use in the debugger
 void dumpInnerHTML(WebCore::HTMLElement*);
 
 void dumpInnerHTML(WebCore::HTMLElement* element)
 {
     printf("%s\n", element->innerHTML().ascii().data());
 }
 #endif