_, err := f.Write(chunk[:frag])
		if err != nil {
			t.Fatal("write chunk:", err)
		}
	}
	end := []byte("END\n")
	_, err = f.Write(end)
	if err != nil {
		t.Fatal("write end:", err)
	}
	if err := w.Close(); err != nil {
		t.Fatal(err)
	}

	// read back zip file and check that we get to the end of it
	r, err := NewReader(buf, buf.Size())
	if err != nil {
		t.Fatal("reader:", err)
	}

// ComplexType is here for the purposes of documentation only. It is a
// stand-in for either complex type: complex64 or complex128.
type ComplexType complex64

// The append built-in function appends elements to the end of a slice. If
// it has sufficient capacity, the destination is resliced to accommodate the
// new elements. If it does not, a new underlying array will be allocated.

C struct fields that cannot be expressed in Go, such as bit fields
or misaligned data, are omitted in the Go struct, replaced by
appropriate padding to reach the next field or the end of the struct.

The standard C numeric types are available under the names
C.char, C.schar (signed char), C.uchar (unsigned char),
C.short, C.ushort (unsigned short), C.int, C.uint (unsigned int),

		return
	}
	got, err := io.ReadAll(rw)
	if err != nil {
		t.Errorf("%v: OpenRaw ReadAll error=%v", f.Name, err)
		return
	}
	end := uint64(start) + f.CompressedSize64
	want := raw[start:end]
	if !bytes.Equal(got, want) {
		t.Logf("got %q", got)
		t.Logf("want %q", want)
		t.Errorf("%v: OpenRaw returned unexpected bytes", f.Name)
		return
	}

	r, err := f.Open()

	dst := src[:0]
	for _, s := range src {
		pos, end := s.Offset, s.endOffset()
		pos += blockPadding(+pos) // Round-up to nearest blockSize
		if end != size {
			end -= blockPadding(-end) // Round-down to nearest blockSize
		}
		if pos < end {
			dst = append(dst, sparseEntry{Offset: pos, Length: end - pos})
		}
	}
	return dst
}

		// zip64 end of central directory locator
		b.uint32(directory64LocSignature)
		b.uint32(0)           // number of the disk with the start of the zip64 end of central directory
		b.uint64(uint64(end)) // relative offset of the zip64 end of central directory record
		b.uint32(1)           // total number of disks

}

// Next advances to the next entry in the tar archive.
// The Header.Size determines how many bytes can be read for the next file.
// Any remaining data in the current file is automatically discarded.
// At the end of the archive, Next returns the error io.EOF.
//
// If Next encounters a non-local name (as defined by [filepath.IsLocal])
// and the GODEBUG environment variable contains `tarinsecurepath=0`,

	// Diagnose common mistakes people make,
	// since there is no apifmt to format these files.
	// The missing final newline is important for the
	// final release step of cat next/*.txt >go1.X.txt.
	// If the files don't end in full lines, the concatenation goes awry.
	if strings.Contains(s, "\r") {
		log.Printf("%s: contains CRLFs", filename)
		exitCode = 1
	}
	if filepath.Base(filename) == "go1.4.txt" {