wantMap:  sparseDatas{{0, 1}, {2, 1}, {4, 1}, {6, 1}},
		wantSize: 03333,
	}, {
		input: makeInput(FormatGNU, "",
			append(append(
				makeSparseStrings(sparseDatas{{0, 1}, {2, 1}}),
				[]string{"", ""}...),
				makeSparseStrings(sparseDatas{{4, 1}, {6, 1}})...)...),
		wantMap: sparseDatas{{0, 1}, {2, 1}, {4, 1}, {6, 1}},
	}, {

// deals with sparseDatas.
//
// However, the external API uses sparseHoles instead of sparseDatas because the
// zero value of sparseHoles logically represents a normal file (i.e., there are
// no holes in it). On the other hand, the zero value of sparseDatas implies
// that the file has no data in it, which is rather odd.
//

			sph = alignSparseEntries(sph, hdr.Size)
			spd = invertSparseEntries(sph, hdr.Size)

			// Format the sparse map.
			formatSPD := func(sp sparseDatas, sa sparseArray) sparseDatas {
				for i := 0; len(sp) > 0 && i < sa.MaxEntries(); i++ {
					f.formatNumeric(sa.Entry(i).Offset(), sp[0].Offset)
					f.formatNumeric(sa.Entry(i).Length(), sp[0].Length)
					sp = sp[1:]
				}