// zeroes
	_, err := NewReader(bytes.NewReader(b), size)
	if err != ErrFormat {
		t.Errorf("zeroes: error=%v, want %v", err, ErrFormat)
	}

	// repeated directoryEndSignatures
	sig := make([]byte, 4)
	binary.LittleEndian.PutUint32(sig, directoryEndSignature)
	for i := 0; i < size-4; i += 4 {
		copy(b[i:i+4], sig)
	}
	_, err = NewReader(bytes.NewReader(b), size)
	if err != ErrFormat {

	out, err := cmd.CombinedOutput()
	if err != nil {
		t.Fatalf("%v: %v\n%s", cmd, err, string(out))
	}
	syms := make(map[string]string)
	scanner := bufio.NewScanner(bytes.NewReader(out))
	for scanner.Scan() {
		f := strings.Fields(scanner.Text())
		if len(f) < 3 {
			continue
		}
		syms[f[2]] = f[0]
	}
	if err := scanner.Err(); err != nil {
		t.Fatalf("error reading symbols: %v", err)

			t.Fatalf("creating file %d: %v", i, err)
		}
	}
	if err := w.Close(); err != nil {
		t.Fatalf("Writer.Close: %v", err)
	}
	s := buf.String()
	zr, err := NewReader(strings.NewReader(s), int64(len(s)))
	if err != nil {
		t.Fatalf("NewReader: %v", err)
	}
	if got := len(zr.File); got != nFiles {
		t.Fatalf("File contains %d files, want %d", got, nFiles)
	}
	for i := 0; i < nFiles; i++ {

	// Output:
	// 'Gjnf oevyyvt naq gur fyvgul tbcure...
}

func ExampleReader_Len() {
	fmt.Println(bytes.NewReader([]byte("Hi!")).Len())
	fmt.Println(bytes.NewReader([]byte("こんにちは!")).Len())
	// Output:
	// 3
	// 16
}

func ExampleRepeat() {
	fmt.Printf("ba%s", bytes.Repeat([]byte("na"), 2))
	// Output: banana
}

### Go 1.20

Go 1.20 introduced support for rejecting insecure paths in tar and zip archives,
controlled by the [`tarinsecurepath` setting](/pkg/archive/tar/#Reader.Next)
and the [`zipinsecurepath` setting](/pkg/archive/zip/#NewReader).
These default to `tarinsecurepath=1` and `zipinsecurepath=1`,
preserving the behavior of earlier versions of Go.
A future version of Go may change the defaults to
`tarinsecurepath=0` and `zipinsecurepath=0`.

	if !bytes.Contains(buf.Bytes(), []byte("PaxHeaders.0")) {
		t.Fatal("Expected at least one PAX header to be written.")
	}
	// Test that we can get a long name back out of the archive.
	reader := NewReader(&buf)
	hdr, err = reader.Next()
	if err != nil {
		t.Fatal(err)
	}
	if hdr.Name != longName {
		t.Fatal("Couldn't recover long file name")
	}
}

func TestPaxSymlink(t *testing.T) {

	}
	if _, err := tw.Write(data); err != nil {
		t.Fatalf("tw.Write: %v", err)
	}
	if err := tw.Close(); err != nil {
		t.Fatalf("tw.Close: %v", err)
	}

	// Read it back.
	tr := NewReader(&b)
	rHdr, err := tr.Next()
	if err != nil {
		t.Fatalf("tr.Next: %v", err)
	}
	if !reflect.DeepEqual(rHdr, hdr) {
		t.Errorf("Header mismatch.\n got %+v\nwant %+v", rHdr, hdr)
	}

	// ensure that this error is sticky.
	err error
}

type fileReader interface {
	io.Reader
	fileState

	WriteTo(io.Writer) (int64, error)
}

// NewReader creates a new [Reader] reading from r.
func NewReader(r io.Reader) *Reader {
	return &Reader{r: r, curr: &regFileReader{r, 0}}
}

// Next advances to the next entry in the tar archive.

			log.Fatalf("loading imports: %v\n%s", err, out)
		}

		var stdPackages []string
		importMap := make(map[string]map[string]string)
		importDir := make(map[string]string)
		dec := json.NewDecoder(bytes.NewReader(out))
		for {
			var pkg struct {
				ImportPath, Dir string
				ImportMap       map[string]string
				Standard        bool
			}
			err := dec.Decode(&pkg)
			if err == io.EOF {
				break
			}