if got != v.want {
			t.Errorf("formatPAXTime(%ds, %dns): got %q, want %q",
				v.sec, v.nsec, got, v.want)
		}
	}
}

func TestParsePAXRecord(t *testing.T) {
	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},

	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)
			})

					f.Preamble += fmt.Sprintf("#line %d %q\n", sourceLine(cg), abspath)
					f.Preamble += commentText(cg) + "\n"
					f.Preamble += "#line 1 \"cgo-generated-wrapper\"\n"
				}
			}

		case *ast.FuncDecl:
			// Also, reject attempts to declare methods on C.T or *C.T.
			// (The generated code would otherwise accept this
			// invalid input; see issue #57926.)
			if decl.Recv != nil && len(decl.Recv.List) > 0 {
				recvType := decl.Recv.List[0].Type

entirely using GODEBUG=cgocheck=0. Complete checking of pointer
handling, at some cost in run time, is available by setting
GOEXPERIMENT=cgocheck2 at build time.

It is possible to defeat this enforcement by using the unsafe package,
and of course there is nothing stopping the C code from doing anything
it likes. However, programs that break these rules are likely to fail
in unexpected and unpredictable ways.

		return part.off+part.n > off
	})
	parts := r.buf[skipParts:]
	if len(parts) > 0 {
		skipBytes := off - parts[0].off
		for _, part := range parts {
			repeat := int(min(part.n-skipBytes, int64(len(p)-n)))
			memset(p[n:n+repeat], part.b)
			n += repeat
			if n == len(p) {
				return
			}
			skipBytes = 0
		}
	}
	if n != len(p) {
		err = io.ErrUnexpectedEOF
	}
	return
}

	bigBuf := bytes.Repeat([]byte("a"), 1<<20)

	runOnce := func(buf *bytes.Buffer) {
		buf.Reset()
		zw := NewWriter(buf)
		for j := 0; j < 3; j++ {
			w, _ := zw.CreateHeader(&FileHeader{
				Name:   "foo",
				Method: Deflate,
			})
			w.Write(bigBuf)
		}
		zw.Close()
	}

	b.ReportAllocs()
	// Run once and then reset the timer.

		inputHdrs: map[string]string{paxGNUSparseMajor: "1", paxGNUSparseMinor: "0"},
		wantErr:   ErrHeader,
	}, {
		inputData: padInput(strings.Repeat("0", 300) + "1\n" + strings.Repeat("0", 1000) + "5\n" + strings.Repeat("0", 800) + "2\n"),
		inputHdrs: map[string]string{paxGNUSparseMajor: "1", paxGNUSparseMinor: "0"},
		wantMap:   sparseDatas{{5, 2}},
	}, {
		inputData: padInput("2\n10737418240\n512\n21474836480\n512\n"),

func (b *Buffer) Truncate(n int) {
	if n == 0 {
		b.Reset()
		return
	}
	b.lastRead = opInvalid
	if n < 0 || n > b.Len() {
		panic("bytes.Buffer: truncation out of range")
	}
	b.buf = b.buf[:b.off+n]
}

// Reset resets the buffer to be empty,
// but it retains the underlying storage for use by future writes.
// Reset is the same as [Buffer.Truncate](0).
func (b *Buffer) Reset() {
	b.buf = b.buf[:0]
	b.off = 0

// findBodyOffset does the minimum work to verify the file has a header
// and returns the file body offset.
func (f *File) findBodyOffset() (int64, error) {
	var buf [fileHeaderLen]byte
	if _, err := f.zipr.ReadAt(buf[:], f.headerOffset); err != nil {
		return 0, err
	}
	b := readBuf(buf[:])
	if sig := b.uint32(); sig != fileHeaderSignature {
		return 0, ErrFormat
	}
	b = b[22:] // skip over most of the header

		return nil
	}
	return s.err
}

// Bytes returns the most recent token generated by a call to [Scanner.Scan].
// The underlying array may point to data that will be overwritten
// by a subsequent call to Scan. It does no allocation.
func (s *Scanner) Bytes() []byte {
	return s.token
}

// Text returns the most recent token generated by a call to [Scanner.Scan]
// as a newly allocated string holding its bytes.