func()

in writer.go [251:262]


func (w *Writer) prepare(fh *FileHeader) error {
	if w.last != nil && !w.last.closed {
		if err := w.last.close(); err != nil {
			return err
		}
	}
	if len(w.dir) > 0 && w.dir[len(w.dir)-1].FileHeader == fh {
		// See https://golang.org/issue/11144 confusion.
		return errors.New("archive/zip: invalid duplicate FileHeader")
	}
	return nil
}