Fix detection of compression files without extension

            return false;

        }

        String ext = getExtension(fso);

        if (ext != null) {

            int cc = VALID.length;

            for (int i = 0; i < cc; i++) {

                if (VALID[i].compareTo(ext) == 0) {

                    return true;

                }

            }

        }

        return false;

    }