WeakNodeMap should have an ASSERT for node in WeakNodeMap::put()

Source/core/dom/WeakNodeMap.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "config.h"
 #include "core/dom/WeakNodeMap.h"
 
 #include "core/dom/Node.h"
 
 namespace WebCore {
@@ skipping 52 matching lines @@
     NodeToWeakNodeMaps& allMaps = NodeToWeakNodeMaps::instance();
     for (NodeToValue::iterator it = m_nodeToValue.begin(); it != m_nodeToValue.end(); ++it) {
         Node* node = it->key;
         if (allMaps.removedFromMap(node, this))
             node->clearFlag(Node::HasWeakReferencesFlag);
     }
 }
 
 void WeakNodeMap::put(Node* node, int value)
 {
-    ASSERT(!m_nodeToValue.contains(node));
+    ASSERT(node && !m_nodeToValue.contains(node));
     m_nodeToValue.set(node, value);
     m_valueToNode.set(value, node);
 
     NodeToWeakNodeMaps& maps = NodeToWeakNodeMaps::instance();
     if (maps.addedToMap(node, this))
         node->setFlag(Node::HasWeakReferencesFlag);
 }
 
 int WeakNodeMap::value(Node* node)
 {
@@ skipping 11 matching lines @@
     ASSERT(value);
     m_valueToNode.remove(value);
 }
 
 void WeakNodeMap::notifyNodeDestroyed(Node* node)
 {
     NodeToWeakNodeMaps::instance().nodeDestroyed(node);
 }
 
 }