Bug 81603 [Import/Export] tar import/export does not preserve file permissions
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/wizards/datatransfer/TarFileStructureProvider.java
private TarFile tarFile;
    private TarEntry root = new TarEntry("/");
    private Map children;
    private Map directoryEntryCache = new HashMap();
    /**
     * Creates a <code>TarFileStructureProvider</code>, which will operate
     * on the passed tar file.
     * 
     * @param sourceFile the source TarFile
     */
    public TarFileStructureProvider(TarFile sourceFile) {
        super();
        tarFile = sourceFile;