--- jsr166/src/main/java/util/PriorityQueue.java	2003/08/13 14:11:59	1.28
+++ jsr166/src/main/java/util/PriorityQueue.java	2003/08/25 23:47:01	1.32
@@ -28,6 +28,18 @@
  * elements are added to a priority queue, its capacity grows
  * automatically.  The details of the growth policy are not specified.
  *
+ * <p>The Iterator provided in method {@link #iterator()} is <em>not</em>
+ * guaranteed to traverse the elements of the PriorityQueue in any
+ * particular order. If you need ordered traversal, consider using
+ * <tt>Arrays.sort(pq.toArray())</tt>.
+ *
+ * <p> <strong>Note that this implementation is not synchronized.</strong>
+ * Multiple threads should not access a <tt>PriorityQueue</tt>
+ * instance concurrently if any of the threads modifies the list
+ * structurally. Instead, use the thread-safe {@link
+ * java.util.concurrent.BlockingPriorityQueue} class.
+ *
+ * 
  * <p>Implementation note: this implementation provides O(log(n)) time
  * for the insertion methods (<tt>offer</tt>, <tt>poll</tt>,
  * <tt>remove()</tt> and <tt>add</tt>) methods; linear time for the
@@ -44,6 +56,8 @@
 public class PriorityQueue<E> extends AbstractQueue<E>
     implements Queue<E>, java.io.Serializable {
 
+    private static final long serialVersionUID = -7720805057305804111L;
+
     private static final int DEFAULT_INITIAL_CAPACITY = 11;
 
     /**
@@ -417,8 +431,7 @@ public class PriorityQueue<E> extends Ab
             checkForComodification();
 
             PriorityQueue.this.remove(lastRet);
-            if (lastRet < cursor)
-                cursor--;
+            cursor--;
             lastRet = 0;
             expectedModCount = modCount;
         }
@@ -450,8 +463,6 @@ public class PriorityQueue<E> extends Ab
      * Removes and returns the ith element from queue.  Recall
      * that queue is one-based, so 1 <= i <= size.
      *
-     * XXX: Could further special-case i==size, but is it worth it?
-     * XXX: Could special-case i==0, but is it worth it?
      */
     private E remove(int i) {
         assert i <= size;
@@ -506,7 +517,7 @@ public class PriorityQueue<E> extends Ab
     private void fixDown(int k) {
         int j;
         if (comparator == null) {
-            while ((j = k << 1) <= size) {
+            while ((j = k << 1) <= size && j > 0) {
                 if (j<size && ((Comparable<E>)queue[j]).compareTo((E)queue[j+1]) > 0)
                     j++; // j indexes smallest kid
                 if (((Comparable<E>)queue[k]).compareTo((E)queue[j]) <= 0)
@@ -515,7 +526,7 @@ public class PriorityQueue<E> extends Ab
                 k = j;
             }
         } else {
-            while ((j = k << 1) <= size) {
+            while ((j = k << 1) <= size && j > 0) {
                 if (j < size && comparator.compare((E)queue[j], (E)queue[j+1]) > 0)
                     j++; // j indexes smallest kid
                 if (comparator.compare((E)queue[k], (E)queue[j]) <= 0)