}

// reset clears the block with all zeros.
func (b *block) reset() {
	*b = block{}
}

type headerV7 [blockSize]byte

func (h *headerV7) name() []byte     { return h[000:][:100] }
func (h *headerV7) mode() []byte     { return h[100:][:8] }
func (h *headerV7) uid() []byte      { return h[108:][:8] }
func (h *headerV7) gid() []byte      { return h[116:][:8] }
func (h *headerV7) size() []byte     { return h[124:][:12] }

	for i := 0; i <= len(b)-15; i++ {
		for j := 0; j < 15; j++ {
			b[i+j] = byte(100 + j)
		}
		for j := 0; j < 15; j++ {
			p := IndexByte(b[i:i+15], byte(100+j))
			if p != j {
				t.Errorf("IndexByte(%q, %d) = %d", b[i:i+15], 100+j, p)
			}
		}
		for j := 0; j < 15; j++ {
			b[i+j] = 0
		}
	}
	// Make sure matches outside the slice never trigger.

		{"-0.1", time.Unix(-0, -1e8), true},
		{"-0.01", time.Unix(-0, -1e7), true},
		{"-0.99", time.Unix(-0, -99e7), true},
		{"-0.98", time.Unix(-0, -98e7), true},
		{"-1.1", time.Unix(-1, -1e8), true},
		{"-1.01", time.Unix(-1, -1e7), true},
		{"-2.99", time.Unix(-2, -99e7), true},
		{"-5.98", time.Unix(-5, -98e7), true},
		{"-", time.Time{}, false},
		{"+", time.Time{}, false},
		{"-1.-1", time.Time{}, false},

	tmp := make([]byte, 72)
	for _, growLen := range []int{0, 100, 1000, 10000, 100000} {
		for _, startLen := range []int{0, 100, 1000, 10000, 100000} {
			xBytes := Repeat(x, startLen)

			buf := NewBuffer(xBytes)
			// If we read, this affects buf.off, which is good to test.
			readBytes, _ := buf.Read(tmp)
			yBytes := Repeat(y, growLen)
			allocs := testing.AllocsPerRun(100, func() {
				buf.Grow(growLen)
				buf.Write(yBytes)

		t.Skipf("skipping flaky test on %s; see golang.org/issue/18202", runtime.GOOS)
	}

	if runtime.GOARCH == "mips" || runtime.GOARCH == "mips64" {
		t.Skipf("skipping on %s", runtime.GOARCH)
	}

	attempts := 1000
	threads := 4

	// Restrict the number of attempts based on RLIMIT_NPROC.
	// Tediously, RLIMIT_NPROC was left out of the syscall package,
	// probably because it is not in POSIX.1, so we define it here.

	}
}

func createTestInput(n int) []byte {
	input := make([]byte, n)
	for i := range input {
		// 101 and 251 are arbitrary prime numbers.
		// The idea is to create an input sequence
		// which doesn't repeat too frequently.
		input[i] = byte(i % 251)
		if i%101 == 0 {
			input[i] ^= byte(i / 101)
		}
	}
	return input
}

func TestReaderWriteTo(t *testing.T) {

	{"$0x02", "$2"},
	{"$0x04", "$4"},
	{"$0x3FE", "$1022"},
	{"$0x7fffffe00000", "$140737486258176"},
	{"$0xfffffffffffff001", "$-4095"},
	{"$1", "$1"},
	{"$1.0", "$(1.0)"},
	{"$10", "$10"},
	{"$1000", "$1000"},
	{"$1000000", "$1000000"},
	{"$1000000000", "$1000000000"},
	{"$__tsan_func_enter(SB)", "$__tsan_func_enter(SB)"},
	{"$main(SB)", "$main(SB)"},
	{"$masks<>(SB)", "$masks<>(SB)"},

func stack996()  { var buf [996]byte; use(buf[:]); C.callGoStackCheck() }
func stack1000() { var buf [1000]byte; use(buf[:]); C.callGoStackCheck() }
func stack1004() { var buf [1004]byte; use(buf[:]); C.callGoStackCheck() }
func stack1008() { var buf [1008]byte; use(buf[:]); C.callGoStackCheck() }
func stack1012() { var buf [1012]byte; use(buf[:]); C.callGoStackCheck() }

			Mode:     420,
			Uid:      1000,
			Gid:      1000,
			Size:     200,
			ModTime:  time.Unix(1392395740, 0),
			Typeflag: 0x53,
			Linkname: "",
			Uname:    "david",
			Gname:    "david",
			Devmajor: 0,
			Devminor: 0,
			Format:   FormatGNU,
		}, {
			Name:     "sparse-posix-0.0",
			Mode:     420,
			Uid:      1000,
			Gid:      1000,
			Size:     200,

	go func() {
		// We need the G continue running,
		// so the M has a chance to run this G.
		for {
			select {
			case <-stop:
				return
			case <-time.After(time.Millisecond * 100):
			}
		}
	}()
	defer close(stop)

	for i := 0; i < 1000; i++ {
		if !C.Ctid() {
			t.Fatalf("cgo has not locked OS thread")
		}
	}