Don't move uneditable style and link elements during deletion

Source/core/editing/DeleteSelectionCommand.cpp

 /*
  * Copyright (C) 2005 Apple Computer, Inc.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 409 matching lines @@
 
 void DeleteSelectionCommand::makeStylingElementsDirectChildrenOfEditableRootToPreventStyleLoss()
 {
     RefPtr<Range> range = m_selectionToDelete.toNormalizedRange();
     RefPtr<Node> node = range->firstNode();
     while (node && node != range->pastLastNode()) {
         RefPtr<Node> nextNode = NodeTraversal::next(node.get());
         if ((node->hasTagName(styleTag) && !(toElement(node.get())->hasAttribute(scopedAttr))) || node->hasTagName(linkTag)) {
             nextNode = NodeTraversal::nextSkippingChildren(node.get());
             RefPtr<ContainerNode> rootEditableElement = node->rootEditableElement();
-            removeNode(node);
-            appendNode(node, rootEditableElement);
+            if (rootEditableElement.get()) {
+                removeNode(node);
+                appendNode(node, rootEditableElement);
+            }
         }
         node = nextNode;
     }
 }
 
 void DeleteSelectionCommand::handleGeneralDelete()
 {
     if (m_upstreamStart.isNull())
         return;
 
@@ skipping 387 matching lines @@
 
 // Normally deletion doesn't preserve the typing style that was present before it.  For example,
 // type a character, Bold, then delete the character and start typing.  The Bold typing style shouldn't
 // stick around.  Deletion should preserve a typing style that *it* sets, however.
 bool DeleteSelectionCommand::preservesTypingStyle() const
 {
     return m_typingStyle;
 }
 
 } // namespace WebCore