--- old/src/share/classes/java/util/Collections.java	2013-08-26 20:48:26.089105157 -0700
+++ new/src/share/classes/java/util/Collections.java	2013-08-26 20:48:25.917105149 -0700
@@ -3879,6 +3879,7 @@
                 return batchRemove(c, true);
             }
             private boolean batchRemove(Collection<?> c, boolean complement) {
+                Objects.requireNonNull(c);
                 boolean modified = false;
                 Iterator<Map.Entry<K,V>> it = iterator();
                 while (it.hasNext()) {