testRead{0, "", io.EOF},
		},
	}, {
		maker: makeSparse{makeReg{"abcde", 5}, sparseDatas{{0, 2}, {5, 3}}, 8},
		tests: []testFnc{
			testRemaining{8, 5},
			testRead{3, "ab\x00", nil},
			testRead{10, "\x00\x00cde", io.EOF},
			testRemaining{0, 0},
		},
	}, {
		maker: makeSparse{makeReg{"abcde", 5}, sparseDatas{{0, 2}, {5, 3}}, 8},
		tests: []testFnc{
			testRemaining{8, 5},

	for rno, read := range readers {
		// Some input data that is longer than the minimum reader buffer size.
		const n = 10
		var buf bytes.Buffer
		for i := 0; i < n; i++ {
			buf.WriteString("abcdefg")
		}

		r := NewReaderSize(&buf, minReadBufferSize)
		readTo := func(delim byte, want string) {
			data, err := read(r, delim)
			if err != nil {