--- old/src/share/classes/java/util/AbstractCollection.java	2013-05-06 14:43:31.510817141 -0700
+++ new/src/share/classes/java/util/AbstractCollection.java	2013-05-06 14:43:31.310817131 -0700
@@ -368,6 +368,7 @@
      * @see #contains(Object)
      */
     public boolean removeAll(Collection<?> c) {
+        Objects.requireNonNull(c);
         boolean modified = false;
         Iterator<?> it = iterator();
         while (it.hasNext()) {
@@ -401,6 +402,7 @@
      * @see #contains(Object)
      */
     public boolean retainAll(Collection<?> c) {
+        Objects.requireNonNull(c);
         boolean modified = false;
         Iterator<E> it = iterator();
         while (it.hasNext()) {