--- a/jdk/src/share/classes/java/util/AbstractCollection.java	Tue May 07 11:31:08 2013 -0700
+++ b/jdk/src/share/classes/java/util/AbstractCollection.java	Tue May 07 12:05:52 2013 -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()) {