--- old/src/share/classes/java/util/ArrayList.java	2013-05-06 14:43:32.842817204 -0700
+++ new/src/share/classes/java/util/ArrayList.java	2013-05-06 14:43:32.646817196 -0700
@@ -671,6 +671,7 @@
      * @see Collection#contains(Object)
      */
     public boolean removeAll(Collection<?> c) {
+        Objects.requireNonNull(c);
         return batchRemove(c, false);
     }
 
@@ -691,6 +692,7 @@
      * @see Collection#contains(Object)
      */
     public boolean retainAll(Collection<?> c) {
+        Objects.requireNonNull(c);
         return batchRemove(c, true);
     }