Bug 14531 Unable to use JarPackager headless
Beginning with the 04/23 Integration build, I am unable to utilize the JarPackager in a headless environment. Specifically, I have defined my own Ant tasks which perform operations including jar packaging. The problem is in JarFileExportOperation.getDirtyEditors(Shell parent). Is it possible to accept null for parent and have the method just return an empty array?
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/jarpackager/JarFileExportOperation.java
* The resource must be a file whose file name ends with ".class".
	 * 
	 * @return a <code>true<code> if the given resource is a class file
	 */
	boolean isClassFile(IResource file) {
		return file != null
			&& file.getType() == IFile.FILE
			&& file.getFileExtension() != null
			&& file.getFileExtension().equalsIgnoreCase("class"); 
	}
	/*
	 * Builds and returns a map that has the class files
	 * for each java file in a given directory
	 */
	private Map buildJavaToClassMap(IContainer container) throws CoreException {
		if (!isCompilerGeneratingSourceFileAttribute())
			return null;
		
		if (container == null || !container.isAccessible())
			return new HashMap(0);
		/*
		 * XXX: Bug 6584: Need a way to get class files for a java file (or CU)
		 */
		org.eclipse.jdt.internal.compiler.classfmt.ClassFileReader cfReader;
		IResource[] members= container.members();
		Map map= new HashMap(members.length);
		for (int i= 0;  i < members.length; i++) {
			if (isClassFile(members[i])) {
				IFile classFile= (IFile)members[i];
				try {