w.last = nil
		return dirWriter{}, nil
	}

	fw := &fileWriter{
		header: h,
		zipw:   w.cw,
	}
	w.last = fw
	return fw, nil
}

// Copy copies the file f (obtained from a [Reader]) into w. It copies the raw
// form directly bypassing decompression, compression, and validation.
func (w *Writer) Copy(f *File) error {
	r, err := f.OpenRaw()
	if err != nil {
		return err
	}

			b.Run(v.label, func(b *testing.B) {
				b.ReportAllocs()
				for i := 0; i < b.N; i++ {
					// Writing to io.Discard because we want to
					// test purely the writer code and not bring in disk performance into this.
					tw := NewWriter(io.Discard)
					for _, file := range v.files {
						if err := tw.WriteHeader(file.hdr); err != nil {
							b.Errorf("unexpected WriteHeader error: %v", err)
						}

				// into a constant. E.g:
				//   BC 4,...
				// into
				//   BC $4,...
				prog.From = obj.Addr{
					Type:   obj.TYPE_CONST,
					Offset: p.getConstant(prog, op, &a[0]),
				}

			}

			// Likewise, fixup usage like:
			//   BC x,LT,...
			//   BC x,foo+2,...
			//   BC x,4
			//   BC x,$5
			// into
			//   BC x,CR0LT,...
			//   BC x,CR0EQ,...

					i++
				}
				continue
			}
			buf = append(buf, c)
		}

		f := strings.Fields(string(buf))

		// Turn relative (PC) into absolute (PC) automatically,
		// so that most branch instructions don't need comments
		// giving the absolute form.
		if len(f) > 0 && strings.Contains(printed, "(PC)") {
			index := len(f) - 1
			suf := "(PC)"