Bug 13799 JAR exporter exports class files from output folder
There was a problem with the output folder not being detected as such.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/jarpackager/JarFileExportOperation.java
/*
 * (c) Copyright IBM Corp. 2000, 2002.
 * All Rights Reserved.
 */
package org.eclipse.jdt.internal.ui.jarpackager;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashMap;