if err := w.prepare(fh); err != nil {
		return nil, err
	}

	// The ZIP format has a sad state of affairs regarding character encoding.
	// Officially, the name and comment fields are supposed to be encoded
	// in CP-437 (which is mostly compatible with ASCII), unless the UTF-8
	// flag bit is set. However, there are several problems:
	//
	//	* Many ZIP readers still do not support UTF-8.