8231800: Better listing of arrays

Reviewed-by: alanb, rhalade, ahgross, igerasim

src/share/classes/java/util/ArrayList.java

@@ -175,14 +175,16 @@ public class ArrayList<E> extends AbstractList<E>
      * @throws NullPointerException if the specified collection is null
      */
     public ArrayList(Collection<? extends E> c) {
-        elementData = c.toArray();
-        if ((size = elementData.length) != 0) {
-            // c.toArray might (incorrectly) not return Object[] (see 6260652)
-            if (elementData.getClass() != Object[].class)
-                elementData = Arrays.copyOf(elementData, size, Object[].class);
+        Object[] a = c.toArray();
+        if ((size = a.length) != 0) {
+            if (c.getClass() == ArrayList.class) {
+                elementData = a;
+            } else {
+                elementData = Arrays.copyOf(a, size, Object[].class);
+            }
         } else {
             // replace with empty array.
-            this.elementData = EMPTY_ELEMENTDATA;
+            elementData = EMPTY_ELEMENTDATA;
         }
     }
 

src/share/classes/java/util/PriorityQueue.java

@@ -254,8 +254,7 @@ public class PriorityQueue<E> extends AbstractQueue<E>
 
     private void initElementsFromCollection(Collection<? extends E> c) {
         Object[] a = c.toArray();
-        // If c.toArray incorrectly doesn't return Object[], copy it.
-        if (a.getClass() != Object[].class)
+        if (c.getClass() != ArrayList.class)
             a = Arrays.copyOf(a, a.length, Object[].class);
         int len = a.length;
         if (len == 1 || this.comparator != null)

src/share/classes/java/util/Vector.java

@@ -171,11 +171,13 @@ public class Vector<E>
      * @since   1.2
      */
     public Vector(Collection<? extends E> c) {
-        elementData = c.toArray();
-        elementCount = elementData.length;
-        // c.toArray might (incorrectly) not return Object[] (see 6260652)
-        if (elementData.getClass() != Object[].class)
-            elementData = Arrays.copyOf(elementData, elementCount, Object[].class);
+        Object[] a = c.toArray();
+        elementCount = a.length;
+        if (c.getClass() == ArrayList.class) {
+            elementData = a;
+        } else {
+            elementData = Arrays.copyOf(a, elementCount, Object[].class);
+        }
     }
 
     /**

src/share/classes/java/util/concurrent/CopyOnWriteArrayList.java

@@ -34,6 +34,7 @@
 
 package java.util.concurrent;
 import java.util.AbstractList;
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Comparator;
@@ -135,8 +136,7 @@ public class CopyOnWriteArrayList<E>
             elements = ((CopyOnWriteArrayList<?>)c).getArray();
         else {
             elements = c.toArray();
-            // c.toArray might (incorrectly) not return Object[] (see 6260652)
-            if (elements.getClass() != Object[].class)
+            if (c.getClass() != java.util.ArrayList.class)
                 elements = Arrays.copyOf(elements, elements.length, Object[].class);
         }
         setArray(elements);
@@ -762,6 +762,9 @@ public class CopyOnWriteArrayList<E>
      */
     public int addAllAbsent(Collection<? extends E> c) {
         Object[] cs = c.toArray();
+        if (c.getClass() != ArrayList.class) {
+            cs = cs.clone();
+        }
         if (cs.length == 0)
             return 0;
         final ReentrantLock lock = this.lock;
@@ -822,9 +825,10 @@ public class CopyOnWriteArrayList<E>
         try {
             Object[] elements = getArray();
             int len = elements.length;
-            if (len == 0 && cs.getClass() == Object[].class)
+            if (len == 0 && (c.getClass() == CopyOnWriteArrayList.class ||
+                             c.getClass() == ArrayList.class)) {
                 setArray(cs);
-            else {
+            } else {
                 Object[] newElements = Arrays.copyOf(elements, len + cs.length);
                 System.arraycopy(cs, 0, newElements, len, cs.length);
                 setArray(newElements);

src/share/classes/java/util/concurrent/PriorityBlockingQueue.java

@@ -263,8 +263,7 @@ public class PriorityBlockingQueue<E> extends AbstractQueue<E>
         }
         Object[] a = c.toArray();
         int n = a.length;
-        // If c.toArray incorrectly doesn't return Object[], copy it.
-        if (a.getClass() != Object[].class)
+        if (c.getClass() != java.util.ArrayList.class)
             a = Arrays.copyOf(a, n, Object[].class);
         if (screen && (n == 1 || this.comparator != null)) {
             for (int i = 0; i < n; ++i)