--- jsr166/src/test/tck/ConcurrentSkipListSetTest.java	2012/02/21 01:54:04	1.27
+++ jsr166/src/test/tck/ConcurrentSkipListSetTest.java	2014/12/31 19:05:42	1.31
@@ -4,7 +4,6 @@
  * http://creativecommons.org/publicdomain/zero/1.0/
  */
 
-import junit.framework.*;
 import java.util.Arrays;
 import java.util.BitSet;
 import java.util.Collection;
@@ -17,6 +16,9 @@ import java.util.Set;
 import java.util.SortedSet;
 import java.util.concurrent.ConcurrentSkipListSet;
 
+import junit.framework.Test;
+import junit.framework.TestSuite;
+
 public class ConcurrentSkipListSetTest extends JSR166TestCase {
     public static void main(String[] args) {
         junit.textui.TestRunner.run(suite());
@@ -32,7 +34,7 @@ public class ConcurrentSkipListSetTest e
     }
 
     /**
-     * Creates a set of given size containing consecutive
+     * Returns a new set of given size containing consecutive
      * Integers 0 ... n.
      */
     private ConcurrentSkipListSet<Integer> populatedSet(int n) {
@@ -49,7 +51,7 @@ public class ConcurrentSkipListSetTest e
     }
 
     /**
-     * Creates set of first 5 ints.
+     * Returns a new set of first 5 ints.
      */
     private ConcurrentSkipListSet set5() {
         ConcurrentSkipListSet q = new ConcurrentSkipListSet();
@@ -531,7 +533,7 @@ public class ConcurrentSkipListSetTest e
         NavigableSet x = populatedSet(SIZE);
         NavigableSet y = serialClone(x);
 
-        assertTrue(x != y);
+        assertNotSame(x, y);
         assertEquals(x.size(), y.size());
         assertEquals(x, y);
         assertEquals(y, x);
@@ -685,6 +687,17 @@ public class ConcurrentSkipListSetTest e
                    0, setSize - 1, true, bs);
     }
 
+    /**
+     * addAll is idempotent
+     */
+    public void testAddAll_idempotent() throws Exception {
+        Set x = populatedSet(SIZE);
+        Set y = new ConcurrentSkipListSet(x);
+        y.addAll(x);
+        assertEquals(x, y);
+        assertEquals(y, x);
+    }
+
     static NavigableSet<Integer> newSet(Class cl) throws Exception {
         NavigableSet<Integer> result = (NavigableSet<Integer>) cl.newInstance();
         assertEquals(0, result.size());