--- jsr166/src/main/java/util/ArrayDeque.java	2016/11/28 02:52:36	1.124
+++ jsr166/src/main/java/util/ArrayDeque.java	2017/05/31 19:01:08	1.129
@@ -50,7 +50,7 @@ import java.util.function.UnaryOperator;
  * Iterator} interfaces.
  *
  * <p>This class is a member of the
- * <a href="{@docRoot}/../technotes/guides/collections/index.html">
+ * <a href="{@docRoot}/java/util/package-summary.html#CollectionsFramework">
  * Java Collections Framework</a>.
  *
  * @author  Josh Bloch and Doug Lea
@@ -117,16 +117,16 @@ public class ArrayDeque<E> extends Abstr
         if (jump < needed
             || (newCapacity = (oldCapacity + jump)) - MAX_ARRAY_SIZE > 0)
             newCapacity = newCapacity(needed, jump);
-        elements = Arrays.copyOf(elements, newCapacity);
+        final Object[] es = elements = Arrays.copyOf(elements, newCapacity);
         // Exceptionally, here tail == head needs to be disambiguated
-        if (tail < head || (tail == head && elements[head] != null)) {
+        if (tail < head || (tail == head && es[head] != null)) {
             // wrap around; slide first leg forward to end of array
             int newSpace = newCapacity - oldCapacity;
-            System.arraycopy(elements, head,
-                             elements, head + newSpace,
+            System.arraycopy(es, head,
+                             es, head + newSpace,
                              oldCapacity - head);
-            Arrays.fill(elements, head, head + newSpace, null);
-            head += newSpace;
+            for (int i = head, to = (head += newSpace); i < to; i++)
+                es[i] = null;
         }
         // checkInvariants();
     }
@@ -313,8 +313,7 @@ public class ArrayDeque<E> extends Abstr
     /**
      * Adds all of the elements in the specified collection at the end
      * of this deque, as if by calling {@link #addLast} on each one,
-     * in the order that they are returned by the collection's
-     * iterator.
+     * in the order that they are returned by the collection's iterator.
      *
      * @param c the elements to be inserted into this deque
      * @return {@code true} if this deque changed as a result of the call
@@ -520,8 +519,8 @@ public class ArrayDeque<E> extends Abstr
     /**
      * Retrieves and removes the head of the queue represented by this deque.
      *
-     * This method differs from {@link #poll poll} only in that it throws an
-     * exception if this deque is empty.
+     * This method differs from {@link #poll() poll()} only in that it
+     * throws an exception if this deque is empty.
      *
      * <p>This method is equivalent to {@link #removeFirst}.
      *
@@ -888,6 +887,9 @@ public class ArrayDeque<E> extends Abstr
         }
     }
 
+    /**
+     * @throws NullPointerException {@inheritDoc}
+     */
     public void forEach(Consumer<? super E> action) {
         Objects.requireNonNull(action);
         final Object[] es = elements;
@@ -1076,11 +1078,14 @@ public class ArrayDeque<E> extends Abstr
 
     /**
      * Nulls out slots starting at array index i, upto index end.
+     * Condition i == end means "empty" - nothing to do.
      */
     private static void circularClear(Object[] es, int i, int end) {
+        // assert 0 <= i && i < es.length;
+        // assert 0 <= end && end < es.length;
         for (int to = (i <= end) ? end : es.length;
              ; i = 0, to = end) {
-            Arrays.fill(es, i, to, null);
+            for (; i < to; i++) es[i] = null;
             if (to == end) break;
         }
     }