Merge 116339 - Fix containerForRepaint() assumption about non-null enclosingLayer()

Source/WebCore/rendering/RenderObject.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  *           (C) 2004 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Google Inc. All rights reserved.
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 1237 matching lines @@
 RenderBoxModelObject* RenderObject::containerForRepaint() const
 {
     RenderView* v = view();
     if (!v)
         return 0;
     
     RenderBoxModelObject* repaintContainer = 0;
 
 #if USE(ACCELERATED_COMPOSITING)
     if (v->usesCompositing()) {
-        RenderLayer* compLayer = enclosingLayer()->enclosingCompositingLayerForRepaint();
-        if (compLayer)
-            repaintContainer = compLayer->renderer();
+        if (RenderLayer* parentLayer = enclosingLayer()) {
+            RenderLayer* compLayer = parentLayer->enclosingCompositingLayerForRepaint();
+            if (compLayer)
+                repaintContainer = compLayer->renderer();
+        }
     }
 #endif
     
 #if ENABLE(CSS_FILTERS)
     if (RenderLayer* parentLayer = enclosingLayer()) {
         RenderLayer* enclosingFilterLayer = parentLayer->enclosingFilterLayer();
         if (enclosingFilterLayer)
             return enclosingFilterLayer->renderer();
     }
 #endif
@@ skipping 1670 matching lines @@
 {
     if (object1) {
         const WebCore::RenderObject* root = object1;
         while (root->parent())
             root = root->parent();
         root->showRenderTreeAndMark(object1, "*", object2, "-", 0);
     }
 }
 
 #endif