// struct from its contents. Specified in section B.2.4.2.
func (d *decoder) processDHT(n int) error {
	for n > 0 {
		if n < 17 {
			return FormatError("DHT has wrong length")
		}
		if err := d.readFull(d.tmp[:17]); err != nil {
			return err
		}
		tc := d.tmp[0] >> 4
		if tc > maxTc {
			return FormatError("bad Tc value")
		}
		th := d.tmp[0] & 0x0f

		t.Fatal(err)
	}
	defer server.Close()

	var buf [128]byte
	allocs := testing.AllocsPerRun(1000, func() {
		_, err := server.Write(buf[:])
		if err != nil {
			t.Fatal(err)
		}
		_, err = io.ReadFull(client, buf[:])
		if err != nil {
			t.Fatal(err)
		}
	})
	if allocs > 0 {
		t.Fatalf("got %v; want 0", allocs)
	}

	var bufwrt [128]byte
	ch := make(chan bool)
	defer close(ch)

	//
	// The signature is 64 bytes long (hex-encoded SHA256 hash) and
	// starts with a 16 byte header: len("chunk-signature=") + 64 == 80.
	var signature [80]byte
	_, err = io.ReadFull(cr.reader, signature[:])
	if err == io.EOF {
		err = io.ErrUnexpectedEOF
	}
	if err != nil {
		cr.err = err
		return n, cr.err
	}
	if !bytes.HasPrefix(signature[:], []byte("chunk-signature=")) {

	"debug/macho"
	"encoding/binary"
	"fmt"
	"io"
	"io/fs"
	"os"
)

func readAligned4(r io.Reader, sz int32) ([]byte, error) {
	full := (sz + 3) &^ 3
	data := make([]byte, full)
	_, err := io.ReadFull(r, data)
	if err != nil {
		return nil, err
	}
	data = data[:sz]
	return data, nil
}

func ReadELFNote(filename, name string, typ int32) ([]byte, error) {
	f, err := elf.Open(filename)
	if err != nil {

	if cap(dst) < skip {
		dst = make([]byte, 0, skip+1024)
	}
	dst = dst[:skip]
	if skip > 0 {
		n, err := io.ReadFull(r.buf, dst)
		if err != nil && err != io.ErrUnexpectedEOF {
			// If an EOF happens after reading some but not all the bytes,
			// ReadFull returns ErrUnexpectedEOF.
			return dst[:n], err
		}
		dst = dst[:n]
		if err == io.ErrUnexpectedEOF {
			return dst, io.EOF
		}
	}

	if cap(dst) < skip {
		dst = make([]byte, 0, skip+1024)
	}
	dst = dst[:skip]
	if skip > 0 {
		n, err := io.ReadFull(r.buf, dst)
		if err != nil && err != io.ErrUnexpectedEOF {
			// If an EOF happens after reading some but not all the bytes,
			// ReadFull returns ErrUnexpectedEOF.
			return dst[:n], err
		}
		dst = dst[:n]
		if err == io.ErrUnexpectedEOF {
			return dst, io.EOF
		}
	}

	if length == 0 {
		return []byte{}, false, nil
	}

	data, ok := r.sliceOS(length)
	if ok {
		return data, true, nil
	}

	data = make([]byte, length)
	_, err := io.ReadFull(r, data)
	if err != nil {
		return nil, false, err
	}
	return data, false, nil
}

// SliceRO returns a slice containing the next length bytes of r

func (d *decoder) processSOS(n int) error {
	if d.nComp == 0 {
		return FormatError("missing SOF marker")
	}
	if n < 6 || 4+2*d.nComp < n || n%2 != 0 {
		return FormatError("SOS has wrong length")
	}
	if err := d.readFull(d.tmp[:n]); err != nil {
		return err
	}
	nComp := int(d.tmp[0])
	if n != 4+2*nComp {
		return FormatError("SOS length inconsistent with number of components")
	}
	var scan [maxComponents]struct {

				ctxt.Logf("skipping libgcc file: %v\n", err)
			}
			return
		}
		Exitf("cannot open file %s: %v", name, err)
	}
	defer f.Close()

	var magbuf [len(ARMAG)]byte
	if _, err := io.ReadFull(f, magbuf[:]); err != nil {
		Exitf("file %s too short", name)
	}

	if string(magbuf[:]) != ARMAG {
		Exitf("%s is not an archive file", name)
	}

	var arhdr ArHdr
	l := nextar(f, f.Offset(), &arhdr)

	if !fd.ok() {
		return "", syscall.EINVAL
	}

	status, err := os.Open(fd.dir + "/status")
	if err != nil {
		return "", err
	}
	defer status.Close()
	buf := make([]byte, ln)
	n, err := io.ReadFull(status, buf[:])
	if err != nil {
		return "", err
	}
	return string(buf[:n]), nil
}

func newFileFD(f *os.File) (net *netFD, err error) {
	var ctl *os.File
	close := func(fd int) {
		if err != nil {