Merge 132371 - Crash when trying to write exception message to null console

Source/WebCore/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 5223 matching lines @@
     m_haveExplicitlyDisabledDNSPrefetch = true;
 }
 
 void Document::addMessage(MessageSource source, MessageType type, MessageLevel level, const String& message, const String& sourceURL, unsigned lineNumber, PassRefPtr<ScriptCallStack> callStack)
 {
     if (!isContextThread()) {
         postTask(AddConsoleMessageTask::create(source, type, level, message));
         return;
     }
 
-    if (DOMWindow* window = domWindow())
-        window->console()->addMessage(source, type, level, message, sourceURL, lineNumber, callStack);
+    if (DOMWindow* window = domWindow()) {
+        if (Console* console = window->console())
+            console->addMessage(source, type, level, message, sourceURL, lineNumber, callStack);
+    }
 }
 
 struct PerformTaskContext {
     WTF_MAKE_NONCOPYABLE(PerformTaskContext); WTF_MAKE_FAST_ALLOCATED;
 public:
     PerformTaskContext(PassRefPtr<DocumentWeakReference> documentReference, PassOwnPtr<ScriptExecutionContext::Task> task)
         : documentReference(documentReference)
         , task(task)
     {
     }
@@ skipping 1139 matching lines @@
     AtomicString localeKey = locale;
     if (locale.isEmpty() || !RuntimeEnabledFeatures::langAttributeAwareFormControlUIEnabled())
         localeKey = defaultLanguage();
     LocaleToLocalizerMap::AddResult result = m_localizerCache.add(localeKey, nullptr);
     if (result.isNewEntry)
         result.iterator->second = Localizer::create(localeKey);
     return *(result.iterator->second);
 }
 
 } // namespace WebCore