// form directly bypassing decompression, compression, and validation.
func (w *Writer) Copy(f *File) error {
	r, err := f.OpenRaw()
	if err != nil {
		return err
	}
	// Copy the FileHeader so w doesn't store a pointer to the data
	// of f's entire archive. See #65499.
	fh := f.FileHeader
	fw, err := w.CreateRaw(&fh)
	if err != nil {
		return err
	}
	_, err = io.Copy(fw, r)
	return err
}