/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

package org.apache.jmeter.engine;

import java.util.LinkedList;

import org.apache.jmeter.engine.util.NoThreadClone;
import org.apache.jmeter.testelement.TestElement;
import org.apache.jorphan.collections.HashTree;
import org.apache.jorphan.collections.HashTreeTraverser;
import org.apache.jorphan.collections.ListedHashTree;

public class TreeCloner implements HashTreeTraverser {

    private ListedHashTree newTree;

    private LinkedList<Object> objects = new LinkedList<Object>();

    private boolean forThread = true;

    public TreeCloner() {
        this(true);
    }

    public TreeCloner(boolean forThread) {
        newTree = new ListedHashTree();
        this.forThread = forThread;
    }

    public void addNode(Object node, HashTree subTree) {
        if ((!forThread || !(node instanceof NoThreadClone)) && (node instanceof TestElement)) {
            node = ((TestElement) node).clone();
            newTree.add(objects, node);
        } else {
            newTree.add(objects, node);
        }
        objects.addLast(node);
    }

    public void subtractNode() {
        objects.removeLast();
    }

    public ListedHashTree getClonedTree() {
        return newTree;
    }

    public void processPath() {
    }

}
@@ -1192,16 +1192,22 @@
 private 
+final 
 ListedHa
@@ -1235,16 +1235,22 @@
 private 
+final 
 LinkedLi
@@ -1309,24 +1309,30 @@
 private 
+final 
 boolean 
 forThrea
@@ -1327,79 +1327,300 @@
 ean 
-forThread = true;%0A%0A    public TreeCloner() %7B%0A        this(true);%0A    %7D%0A
+honourNoThreadClone;%0A%0A    /**%0A     * Clone the test tree, honouring NoThreadClone markers.%0A     * %0A     */%0A    public TreeCloner() %7B%0A        this(true);%0A    %7D%0A%0A    /**%0A     * Clone the test tree.%0A     * %0A     * @param honourNoThreadClone set false to clone NoThreadClone nodes as well%0A     */
 %0A   
@@ -1646,25 +1646,35 @@
 boolean 
-for
+honourNo
 Thread
+Clone
 ) %7B%0A    
@@ -1726,29 +1726,49 @@
 his.
-forThread = for
+honourNoThreadClone = honourNo
 Thread
+Clone
 ;%0A  
@@ -1841,93 +1841,236 @@
     
-if ((!forThread %7C%7C !(node instanceof NoThreadClone)) && (node instanceof TestElement)
+%0A        if ( (node instanceof TestElement) // Check can cast for clone%0A           // Don't clone NoThreadClone unless honourNoThreadClone == false%0A          && (!honourNoThreadClone %7C%7C !(node instanceof NoThreadClone))%0A        
 ) %7B%0A

Make private fields final. Rename and rearrange code to make a bit clearer.