fname = strings.TrimPrefix(fname, "cmd/cgo/internal/")
		if !strings.HasPrefix(fname, "test.") {
			continue
		}
		got = append(got, fname)
	}
	if !reflect.DeepEqual(want, got) {
		t.Errorf("incorrect backtrace:\nwant:\t%v\ngot:\t%v", want, got)
	}

	// Gloss over this by reading headers until we encounter
	// a bad one, and then only report an ErrFormat or UnexpectedEOF if
	// the file count modulo 65536 is incorrect.
	for {
		f := &File{zip: r, zipr: rdr}
		err = readDirectoryHeader(f, buf)
		if err == ErrFormat || err == io.ErrUnexpectedEOF {
			break
		}
		if err != nil {
			return err
		}

			t.Fatal("unexpected error on UnreadRune:", err)
		}
		r2, _, err := r.ReadRune()
		if err != nil {
			t.Fatal("unexpected error reading after unreading:", err)
		}
		if r1 != r2 {
			t.Fatalf("incorrect rune after unread: got %c, want %c", r1, r2)
		}
	}
	if got != want {
		t.Errorf("got %q, want %q", got, want)
	}
}

func TestNoUnreadRuneAfterPeek(t *testing.T) {

		return 0, nil, nil
	}

	// We have a real UTF-8 encoding error. Return a properly encoded error rune
	// but advance only one byte. This matches the behavior of a range loop over
	// an incorrectly encoded string.
	return 1, errorRune, nil
}

// dropCR drops a terminal \r from the data.
func dropCR(data []byte) []byte {
	if len(data) > 0 && data[len(data)-1] == '\r' {
		return data[0 : len(data)-1]

		}
		if nbytes != size {
			t.Fatalf("WriteRune(%U) expected %d, got %d", r, size, nbytes)
		}
		n += size
	}
	b = b[0:n]

	// Check the resulting bytes
	if !Equal(buf.Bytes(), b) {
		t.Fatalf("incorrect result from WriteRune: %q not %q", buf.Bytes(), b)
	}

	p := make([]byte, utf8.UTFMax)
	// Read it back with ReadRune
	for r := rune(0); r < NRune; r++ {
		size := utf8.EncodeRune(p, r)

This package does not support disk spanning.

A note about ZIP64:

To be backwards compatible the FileHeader has both 32 and 64 bit Size
fields. The 64 bit fields will always contain the correct value and
for normal archives both fields will be the same. For files requiring
the ZIP64 format the 32 bit fields will be 0xffffffff and the 64 bit
fields must be used instead.

			}

			for i, hdr := range hdrs {
				if i >= len(v.headers) {
					t.Fatalf("entry %d: unexpected header:\ngot %+v", i, *hdr)
				}
				if !reflect.DeepEqual(*hdr, *v.headers[i]) {
					t.Fatalf("entry %d: incorrect header:\ngot  %+v\nwant %+v", i, *hdr, *v.headers[i])
				}
			}
			if len(hdrs) != len(v.headers) {
				t.Fatalf("got %d headers, want %d headers", len(hdrs), len(v.headers))
			}

			}
		}
	}
}

// test a small index across all page offsets
func TestIndexByteSmall(t *testing.T) {
	b := make([]byte, 5015) // bigger than a page
	// Make sure we find the correct byte even when straddling a page.
	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))

// Copyright 2015 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

//go:build ignore

// detect attempts to autodetect the correct
// values of the environment variables
// used by go_ios_exec.
// detect shells out to ideviceinfo, a third party program that can
// be obtained by following the instructions at
// https://github.com/libimobiledevice/libimobiledevice.

	s := NewScanner(strings.NewReader(text + "\n"))
	s.Buffer(make([]byte, 100), 3*MaxScanTokenSize)
	for s.Scan() {
		token := s.Text()
		if token != text {
			t.Errorf("scan got incorrect token of length %d", len(token))
		}
	}
	if s.Err() != nil {
		t.Fatal("after scan:", s.Err())
	}
}

// negativeEOFReader returns an invalid -1 at the end, as though it