--- old/src/share/classes/java/util/HashMap.java	2013-11-25 20:28:10.884705753 -0800
+++ new/src/share/classes/java/util/HashMap.java	2013-11-25 20:28:10.664705742 -0800
@@ -1212,6 +1212,8 @@
     @Override
     public V merge(K key, V value,
                    BiFunction<? super V, ? super V, ? extends V> remappingFunction) {
+        if (value == null)
+            throw new NullPointerException();
         if (remappingFunction == null)
             throw new NullPointerException();
         int hash = hash(key);