b.uint32(h.CRC32)
		if h.isZip64() || h.offset >= uint32max {
			// the file needs a zip64 header. store maxint in both
			// 32 bit size fields (and offset later) to signal that the
			// zip64 extra header should be used.
			b.uint32(uint32max) // compressed size
			b.uint32(uint32max) // uncompressed size

			// append a zip64 extra block to Extra
			var buf [28]byte // 2x uint16 + 3x uint64
			eb := writeBuf(buf[:])

		return -1, nil // the file is not a valid zip64-file
	}
	p := b.uint64()      // relative offset of the zip64 end of central directory record
	if b.uint32() != 1 { // total number of disks
		return -1, nil // the file is not a valid zip64-file
	}
	return int64(p), nil
}

// readDirectory64End reads the zip64 directory end and updates the

			},
		},
	},
	{
		Name: "zip64.zip",
		File: []ZipTestFile{
			{
				Name:     "README",
				Content:  []byte("This small file is in ZIP64 format.\n"),
				Modified: time.Date(2012, 8, 10, 14, 33, 32, 0, time.UTC),
				Mode:     0644,
			},
		},
	},
	// Another zip64 file with different Extras fields. (golang.org/issue/7069)
	{
		Name: "zip64-2.zip",
		File: []ZipTestFile{
			{