--- a/src/treecms/proto/test/PreOrderTreeWalker.java	Mon Aug 30 00:05:44 2010 +0900
+++ b/src/treecms/proto/test/PreOrderTreeWalker.java	Mon Aug 30 00:48:50 2010 +0900
@@ -22,28 +22,25 @@
 	}
 	class IteratorState implements Iterator<NodeAPI> {
 		LinkedList<NodeState>nodeStack;
-		List<NodeAPI> children;
 		int position;
 		NodeAPI current, next;
 		
 		IteratorState(NodeAPI root) {
 			current = root;
-			children = root.getChildList();
 			position = 0;
 			nodeStack = new LinkedList<NodeState>();
 		}
 		public boolean hasNext() {
-			while (position>=children.size()) {
+			while (position>=current.getChildList().size()) {
 				if (nodeStack.isEmpty()) return false;
-				children = nodeStack.getLast().node.getChildList();
-				position = nodeStack.getLast().position;
-				nodeStack.removeLast();
+				NodeState s =  nodeStack.poll();
+				current = s.node;
+				position = s.position;
 			}
-			next = children.get(position++);
+			next = current.getChildList().get(position++);
 			if (! next.getChildList().isEmpty()) {
 				nodeStack.addLast(new NodeState(current,position));
 				current = next;
-				children = next.getChildList();
 				position = 0;
 			}
 			return true;