--- jsr166/src/main/java/util/ArrayList.java	2005/11/25 13:27:05	1.1
+++ jsr166/src/main/java/util/ArrayList.java	2005/11/25 13:34:29	1.2
@@ -123,20 +123,40 @@ public class ArrayList<E> extends Abstra
     /**
      * Constructs a list containing the elements of the specified
      * collection, in the order they are returned by the collection's
-     * iterator.  
+     * iterator.  The <tt>ArrayList</tt> instance has an initial capacity of
+     * 110% the size of the specified collection.
      *
      * @param c the collection whose elements are to be placed into this list
      * @throws NullPointerException if the specified collection is null
      */
     public ArrayList(Collection<? extends E> c) {
-        Object[] a = c.toArray();
-        // If c.toArray incorrectly doesn't return Object[], copy it.
-        if (a.getClass() != Object[].class)
-            a = Arrays.copyOf(a, a.length, Object[].class);
-        elementData = a;
-        size = a.length;
+	int size = c.size();
+	// 10% for growth
+	int cap = ((size/10)+1)*11;
+	if (cap > 0) {
+	    Object[] a = new Object[cap];
+	    a[size] = a[size+1] = UNALLOCATED;
+	    Object[] b = c.toArray(a);
+	    if (b[size] == null && b[size+1] == UNALLOCATED) {
+		b[size+1] = null;
+		elementData = b;
+		this.size = size;
+		return;
+	    }
+	}
+	initFromConcurrentlyMutating(c);
     }
-
+    
+    private void initFromConcurrentlyMutating(Collection<? extends E> c) {
+	elementData = c.toArray();
+	size = elementData.length;
+	// c.toArray might (incorrectly) not return Object[] (see 6260652)
+	if (elementData.getClass() != Object[].class)
+	    elementData = Arrays.copyOf(elementData, size, Object[].class);
+    }
+    
+    private final static Object UNALLOCATED = new Object();
+    
     /**
      * Trims the capacity of this <tt>ArrayList</tt> instance to be the
      * list's current size.  An application can use this operation to minimize