medName := strings.Repeat("CD", 50)
	longName := strings.Repeat("AB", 100)

	vectors := []struct {
		in      string
		wantRes string
		wantKey string
		wantVal string
		ok      bool
	}{
		{"6 k=v\n\n", "\n", "k", "v", true},
		{"19 path=/etc/hosts\n", "", "path", "/etc/hosts", true},
		{"210 path=" + longName + "\nabc", "abc", "path", longName, true},

	const longName = "././@LongLink"
	if len(hdr.Name) > nameSize {
		data := hdr.Name + "\x00"
		if err := tw.writeRawFile(longName, data, TypeGNULongName, FormatGNU); err != nil {
			return err
		}
	}
	if len(hdr.Linkname) > nameSize {
		data := hdr.Linkname + "\x00"
		if err := tw.writeRawFile(longName, data, TypeGNULongLink, FormatGNU); err != nil {
			return err
		}

longname/longname/longname/longname/longname/longname/longname/longname/longname/longname/longname/longname/longname/longname/longname/file.txt hello...

				Typeflag: TypeReg,
				Name:     strings.Repeat("longname/", 15) + "16gig.txt",
				Size:     16 << 30,
				Mode:     0644,
				Uid:      1000,
				Gid:      1000,
				Uname:    "guillaume",
				Gname:    "guillaume",
				ModTime:  time.Unix(1399583047, 0),
			}, nil},
		},
	}, {
		// This file was produced using GNU tar v1.17.
		//	gnutar -b 4 --format=ustar (longname/)*15 + file.txt
		file: "testdata/ustar.tar",