// Copyright 2009 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. package tar import ( "bytes" "crypto/md5" "fmt" "io" "io/ioutil" "math" "os" "reflect" "strings" "testing" "time" ) type untarTest struct { file string // Test input file headers []*Header // Expected output headers chksums []string // MD5 checksum of files, leave as nil if not checked err error // Expected error to occur } var gnuTarTest = &untarTest{ file: "testdata/gnu.tar", headers: []*Header{ { Name: "small.txt", Mode: 0640, Uid: 73025, Gid: 5000, Size: 5, ModTime: time.Unix(1244428340, 0), Typeflag: '0', Uname: "dsymonds", Gname: "eng", }, { Name: "small2.txt", Mode: 0640, Uid: 73025, Gid: 5000, Size: 11, ModTime: time.Unix(1244436044, 0), Typeflag: '0', Uname: "dsymonds", Gname: "eng", }, }, chksums: []string{ "e38b27eaccb4391bdec553a7f3ae6b2f", "c65bd2e50a56a2138bf1716f2fd56fe9", }, } var sparseTarTest = &untarTest{ file: "testdata/sparse-formats.tar", headers: []*Header{ { Name: "sparse-gnu", Mode: 420, Uid: 1000, Gid: 1000, Size: 200, ModTime: time.Unix(1392395740, 0), Typeflag: 0x53, Linkname: "", Uname: "david", Gname: "david", Devmajor: 0, Devminor: 0, }, { Name: "sparse-posix-0.0", Mode: 420, Uid: 1000, Gid: 1000, Size: 200, ModTime: time.Unix(1392342187, 0), Typeflag: 0x30, Linkname: "", Uname: "david", Gname: "david", Devmajor: 0, Devminor: 0, }, { Name: "sparse-posix-0.1", Mode: 420, Uid: 1000, Gid: 1000, Size: 200, ModTime: time.Unix(1392340456, 0), Typeflag: 0x30, Linkname: "", Uname: "david", Gname: "david", Devmajor: 0, Devminor: 0, }, { Name: "sparse-posix-1.0", Mode: 420, Uid: 1000, Gid: 1000, Size: 200, ModTime: time.Unix(1392337404, 0), Typeflag: 0x30, Linkname: "", Uname: "david", Gname: "david", Devmajor: 0, Devminor: 0, }, { Name: "end", Mode: 420, Uid: 1000, Gid: 1000, Size: 4, ModTime: time.Unix(1392398319, 0), Typeflag: 0x30, Linkname: "", Uname: "david", Gname: "david", Devmajor: 0, Devminor: 0, }, }, chksums: []string{ "6f53234398c2449fe67c1812d993012f", "6f53234398c2449fe67c1812d993012f", "6f53234398c2449fe67c1812d993012f", "6f53234398c2449fe67c1812d993012f", "b0061974914468de549a2af8ced10316", }, } var untarTests = []*untarTest{ gnuTarTest, sparseTarTest, { file: "testdata/star.tar", headers: []*Header{ { Name: "small.txt", Mode: 0640, Uid: 73025, Gid: 5000, Size: 5, ModTime: time.Unix(1244592783, 0), Typeflag: '0', Uname: "dsymonds", Gname: "eng", AccessTime: time.Unix(1244592783, 0), ChangeTime: time.Unix(1244592783, 0), }, { Name: "small2.txt", Mode: 0640, Uid: 73025, Gid: 5000, Size: 11, ModTime: time.Unix(1244592783, 0), Typeflag: '0', Uname: "dsymonds", Gname: "eng", AccessTime: time.Unix(1244592783, 0), ChangeTime: time.Unix(1244592783, 0), }, }, }, { file: "testdata/v7.tar", headers: []*Header{ { Name: "small.txt", Mode: 0444, Uid: 73025, Gid: 5000, Size: 5, ModTime: time.Unix(1244593104, 0), Typeflag: '\x00', }, { Name: "small2.txt", Mode: 0444, Uid: 73025, Gid: 5000, Size: 11, ModTime: time.Unix(1244593104, 0), Typeflag: '\x00', }, }, }, { file: "testdata/pax.tar", headers: []*Header{ { Name: "a/123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100", Mode: 0664, Uid: 1000, Gid: 1000, Uname: "shane", Gname: "shane", Size: 7, ModTime: time.Unix(1350244992, 23960108), ChangeTime: time.Unix(1350244992, 23960108), AccessTime: time.Unix(1350244992, 23960108), Typeflag: TypeReg, }, { Name: "a/b", Mode: 0777, Uid: 1000, Gid: 1000, Uname: "shane", Gname: "shane", Size: 0, ModTime: time.Unix(1350266320, 910238425), ChangeTime: time.Unix(1350266320, 910238425), AccessTime: time.Unix(1350266320, 910238425), Typeflag: TypeSymlink, Linkname: "123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100", }, }, }, { file: "testdata/nil-uid.tar", // golang.org/issue/5290 headers: []*Header{ { Name: "P1050238.JPG.log", Mode: 0664, Uid: 0, Gid: 0, Size: 14, ModTime: time.Unix(1365454838, 0), Typeflag: TypeReg, Linkname: "", Uname: "eyefi", Gname: "eyefi", Devmajor: 0, Devminor: 0, }, }, }, { file: "testdata/xattrs.tar", headers: []*Header{ { Name: "small.txt", Mode: 0644, Uid: 1000, Gid: 10, Size: 5, ModTime: time.Unix(1386065770, 448252320), Typeflag: '0', Uname: "alex", Gname: "wheel", AccessTime: time.Unix(1389782991, 419875220), ChangeTime: time.Unix(1389782956, 794414986), Xattrs: map[string]string{ "user.key": "value", "user.key2": "value2", // Interestingly, selinux encodes the terminating null inside the xattr "security.selinux": "unconfined_u:object_r:default_t:s0\x00", }, }, { Name: "small2.txt", Mode: 0644, Uid: 1000, Gid: 10, Size: 11, ModTime: time.Unix(1386065770, 449252304), Typeflag: '0', Uname: "alex", Gname: "wheel", AccessTime: time.Unix(1389782991, 419875220), ChangeTime: time.Unix(1386065770, 449252304), Xattrs: map[string]string{ "security.selinux": "unconfined_u:object_r:default_t:s0\x00", }, }, }, }, { file: "testdata/neg-size.tar", err: ErrHeader, }, { file: "testdata/issue10968.tar", err: ErrHeader, }, { file: "testdata/issue11169.tar", // TODO(dsnet): Currently the library does not detect that this file is // malformed. Instead it incorrectly believes that file just ends. // err: ErrHeader, }, } func TestReader(t *testing.T) { for i, v := range untarTests { f, err := os.Open(v.file) if err != nil { t.Errorf("file %s, test %d: unexpected error: %v", v.file, i, err) continue } defer f.Close() // Capture all headers and checksums. var ( tr = NewReader(f) hdrs []*Header chksums []string rdbuf = make([]byte, 8) ) for { var hdr *Header hdr, err = tr.Next() if err != nil { if err == io.EOF { err = nil // Expected error } break } hdrs = append(hdrs, hdr) if v.chksums == nil { continue } h := md5.New() _, err = io.CopyBuffer(h, tr, rdbuf) // Effectively an incremental read if err != nil { break } chksums = append(chksums, fmt.Sprintf("%x", h.Sum(nil))) } for j, hdr := range hdrs { if j >= len(v.headers) { t.Errorf("file %s, test %d, entry %d: unexpected header:\ngot %+v", v.file, i, j, *hdr) continue } if !reflect.DeepEqual(*hdr, *v.headers[j]) { t.Errorf("file %s, test %d, entry %d: incorrect header:\ngot %+v\nwant %+v", v.file, i, j, *hdr, *v.headers[j]) } } if len(hdrs) != len(v.headers) { t.Errorf("file %s, test %d: got %d headers, want %d headers", v.file, i, len(hdrs), len(v.headers)) } for j, sum := range chksums { if j >= len(v.chksums) { t.Errorf("file %s, test %d, entry %d: unexpected sum: got %s", v.file, i, j, sum) continue } if sum != v.chksums[j] { t.Errorf("file %s, test %d, entry %d: incorrect checksum: got %s, want %s", v.file, i, j, sum, v.chksums[j]) } } if err != v.err { t.Errorf("file %s, test %d: unexpected error: got %v, want %v", v.file, i, err, v.err) } f.Close() } } func TestPartialRead(t *testing.T) { f, err := os.Open("testdata/gnu.tar") if err != nil { t.Fatalf("Unexpected error: %v", err) } defer f.Close() tr := NewReader(f) // Read the first four bytes; Next() should skip the last byte. hdr, err := tr.Next() if err != nil || hdr == nil { t.Fatalf("Didn't get first file: %v", err) } buf := make([]byte, 4) if _, err := io.ReadFull(tr, buf); err != nil { t.Fatalf("Unexpected error: %v", err) } if expected := []byte("Kilt"); !bytes.Equal(buf, expected) { t.Errorf("Contents = %v, want %v", buf, expected) } // Second file hdr, err = tr.Next() if err != nil || hdr == nil { t.Fatalf("Didn't get second file: %v", err) } buf = make([]byte, 6) if _, err := io.ReadFull(tr, buf); err != nil { t.Fatalf("Unexpected error: %v", err) } if expected := []byte("Google"); !bytes.Equal(buf, expected) { t.Errorf("Contents = %v, want %v", buf, expected) } } func TestParsePAXHeader(t *testing.T) { paxTests := [][3]string{ {"a", "a=name", "10 a=name\n"}, // Test case involving multiple acceptable lengths {"a", "a=name", "9 a=name\n"}, // Test case involving multiple acceptable length {"mtime", "mtime=1350244992.023960108", "30 mtime=1350244992.023960108\n"}} for _, test := range paxTests { key, expected, raw := test[0], test[1], test[2] reader := bytes.NewReader([]byte(raw)) headers, err := parsePAX(reader) if err != nil { t.Errorf("Couldn't parse correctly formatted headers: %v", err) continue } if strings.EqualFold(headers[key], expected) { t.Errorf("mtime header incorrectly parsed: got %s, wanted %s", headers[key], expected) continue } trailer := make([]byte, 100) n, err := reader.Read(trailer) if err != io.EOF || n != 0 { t.Error("Buffer wasn't consumed") } } badHeaderTests := [][]byte{ []byte("3 somelongkey=\n"), []byte("50 tooshort=\n"), } for _, test := range badHeaderTests { if _, err := parsePAX(bytes.NewReader(test)); err != ErrHeader { t.Fatal("Unexpected success when parsing bad header") } } } func TestParsePAXTime(t *testing.T) { // Some valid PAX time values timestamps := map[string]time.Time{ "1350244992.023960108": time.Unix(1350244992, 23960108), // The common case "1350244992.02396010": time.Unix(1350244992, 23960100), // Lower precision value "1350244992.0239601089": time.Unix(1350244992, 23960108), // Higher precision value "1350244992": time.Unix(1350244992, 0), // Low precision value } for input, expected := range timestamps { ts, err := parsePAXTime(input) if err != nil { t.Fatal(err) } if !ts.Equal(expected) { t.Fatalf("Time parsing failure %s %s", ts, expected) } } } func TestMergePAX(t *testing.T) { hdr := new(Header) // Test a string, integer, and time based value. headers := map[string]string{ "path": "a/b/c", "uid": "1000", "mtime": "1350244992.023960108", } err := mergePAX(hdr, headers) if err != nil { t.Fatal(err) } want := &Header{ Name: "a/b/c", Uid: 1000, ModTime: time.Unix(1350244992, 23960108), } if !reflect.DeepEqual(hdr, want) { t.Errorf("incorrect merge: got %+v, want %+v", hdr, want) } } func TestSparseFileReader(t *testing.T) { var vectors = []struct { realSize int64 // Real size of the output file sparseMap []sparseEntry // Input sparse map sparseData string // Input compact data expected string // Expected output data err error // Expected error outcome }{{ realSize: 8, sparseMap: []sparseEntry{ {offset: 0, numBytes: 2}, {offset: 5, numBytes: 3}, }, sparseData: "abcde", expected: "ab\x00\x00\x00cde", }, { realSize: 10, sparseMap: []sparseEntry{ {offset: 0, numBytes: 2}, {offset: 5, numBytes: 3}, }, sparseData: "abcde", expected: "ab\x00\x00\x00cde\x00\x00", }, { realSize: 8, sparseMap: []sparseEntry{ {offset: 1, numBytes: 3}, {offset: 6, numBytes: 2}, }, sparseData: "abcde", expected: "\x00abc\x00\x00de", }, { realSize: 8, sparseMap: []sparseEntry{ {offset: 1, numBytes: 3}, {offset: 6, numBytes: 0}, {offset: 6, numBytes: 0}, {offset: 6, numBytes: 2}, }, sparseData: "abcde", expected: "\x00abc\x00\x00de", }, { realSize: 10, sparseMap: []sparseEntry{ {offset: 1, numBytes: 3}, {offset: 6, numBytes: 2}, }, sparseData: "abcde", expected: "\x00abc\x00\x00de\x00\x00", }, { realSize: 10, sparseMap: []sparseEntry{ {offset: 1, numBytes: 3}, {offset: 6, numBytes: 2}, {offset: 8, numBytes: 0}, {offset: 8, numBytes: 0}, {offset: 8, numBytes: 0}, {offset: 8, numBytes: 0}, }, sparseData: "abcde", expected: "\x00abc\x00\x00de\x00\x00", }, { realSize: 2, sparseMap: []sparseEntry{}, sparseData: "", expected: "\x00\x00", }, { realSize: -2, sparseMap: []sparseEntry{}, err: ErrHeader, }, { realSize: -10, sparseMap: []sparseEntry{ {offset: 1, numBytes: 3}, {offset: 6, numBytes: 2}, }, sparseData: "abcde", err: ErrHeader, }, { realSize: 10, sparseMap: []sparseEntry{ {offset: 1, numBytes: 3}, {offset: 6, numBytes: 5}, }, sparseData: "abcde", err: ErrHeader, }, { realSize: 35, sparseMap: []sparseEntry{ {offset: 1, numBytes: 3}, {offset: 6, numBytes: 5}, }, sparseData: "abcde", err: io.ErrUnexpectedEOF, }, { realSize: 35, sparseMap: []sparseEntry{ {offset: 1, numBytes: 3}, {offset: 6, numBytes: -5}, }, sparseData: "abcde", err: ErrHeader, }, { realSize: 35, sparseMap: []sparseEntry{ {offset: math.MaxInt64, numBytes: 3}, {offset: 6, numBytes: -5}, }, sparseData: "abcde", err: ErrHeader, }, { realSize: 10, sparseMap: []sparseEntry{ {offset: 1, numBytes: 3}, {offset: 2, numBytes: 2}, }, sparseData: "abcde", err: ErrHeader, }} for i, v := range vectors { r := bytes.NewReader([]byte(v.sparseData)) rfr := ®FileReader{r: r, nb: int64(len(v.sparseData))} var sfr *sparseFileReader var err error var buf []byte sfr, err = newSparseFileReader(rfr, v.sparseMap, v.realSize) if err != nil { goto fail } if sfr.numBytes() != int64(len(v.sparseData)) { t.Errorf("test %d, numBytes() before reading: got %d, want %d", i, sfr.numBytes(), len(v.sparseData)) } buf, err = ioutil.ReadAll(sfr) if err != nil { goto fail } if string(buf) != v.expected { t.Errorf("test %d, ReadAll(): got %q, want %q", i, string(buf), v.expected) } if sfr.numBytes() != 0 { t.Errorf("test %d, numBytes() after reading: got %d, want %d", i, sfr.numBytes(), 0) } fail: if err != v.err { t.Errorf("test %d, unexpected error: got %v, want %v", i, err, v.err) } } } func TestReadGNUSparseMap0x1(t *testing.T) { const ( maxUint = ^uint(0) maxInt = int(maxUint >> 1) ) var ( big1 = fmt.Sprintf("%d", int64(maxInt)) big2 = fmt.Sprintf("%d", (int64(maxInt)/2)+1) big3 = fmt.Sprintf("%d", (int64(maxInt) / 3)) ) var vectors = []struct { extHdrs map[string]string // Input data sparseMap []sparseEntry // Expected sparse entries to be outputted err error // Expected errors that may be raised }{{ extHdrs: map[string]string{paxGNUSparseNumBlocks: "-4"}, err: ErrHeader, }, { extHdrs: map[string]string{paxGNUSparseNumBlocks: "fee "}, err: ErrHeader, }, { extHdrs: map[string]string{ paxGNUSparseNumBlocks: big1, paxGNUSparseMap: "0,5,10,5,20,5,30,5", }, err: ErrHeader, }, { extHdrs: map[string]string{ paxGNUSparseNumBlocks: big2, paxGNUSparseMap: "0,5,10,5,20,5,30,5", }, err: ErrHeader, }, { extHdrs: map[string]string{ paxGNUSparseNumBlocks: big3, paxGNUSparseMap: "0,5,10,5,20,5,30,5", }, err: ErrHeader, }, { extHdrs: map[string]string{ paxGNUSparseNumBlocks: "4", paxGNUSparseMap: "0.5,5,10,5,20,5,30,5", }, err: ErrHeader, }, { extHdrs: map[string]string{ paxGNUSparseNumBlocks: "4", paxGNUSparseMap: "0,5.5,10,5,20,5,30,5", }, err: ErrHeader, }, { extHdrs: map[string]string{ paxGNUSparseNumBlocks: "4", paxGNUSparseMap: "0,fewafewa.5,fewafw,5,20,5,30,5", }, err: ErrHeader, }, { extHdrs: map[string]string{ paxGNUSparseNumBlocks: "4", paxGNUSparseMap: "0,5,10,5,20,5,30,5", }, sparseMap: []sparseEntry{{0, 5}, {10, 5}, {20, 5}, {30, 5}}, }} for i, v := range vectors { sp, err := readGNUSparseMap0x1(v.extHdrs) if !reflect.DeepEqual(sp, v.sparseMap) && !(len(sp) == 0 && len(v.sparseMap) == 0) { t.Errorf("test %d, readGNUSparseMap0x1(...): got %v, want %v", i, sp, v.sparseMap) } if err != v.err { t.Errorf("test %d, unexpected error: got %v, want %v", i, err, v.err) } } } func TestReadGNUSparseMap1x0(t *testing.T) { // This test uses lots of holes so the sparse header takes up more than two blocks numEntries := 100 expected := make([]sparseEntry, 0, numEntries) sparseMap := new(bytes.Buffer) fmt.Fprintf(sparseMap, "%d\n", numEntries) for i := 0; i < numEntries; i++ { offset := int64(2048 * i) numBytes := int64(1024) expected = append(expected, sparseEntry{offset: offset, numBytes: numBytes}) fmt.Fprintf(sparseMap, "%d\n%d\n", offset, numBytes) } // Make the header the smallest multiple of blockSize that fits the sparseMap headerBlocks := (sparseMap.Len() + blockSize - 1) / blockSize bufLen := blockSize * headerBlocks buf := make([]byte, bufLen) copy(buf, sparseMap.Bytes()) // Get an reader to read the sparse map r := bytes.NewReader(buf) // Read the sparse map sp, err := readGNUSparseMap1x0(r) if err != nil { t.Errorf("Unexpected error: %v", err) } if !reflect.DeepEqual(sp, expected) { t.Errorf("Incorrect sparse map: got %v, wanted %v", sp, expected) } } func TestUninitializedRead(t *testing.T) { test := gnuTarTest f, err := os.Open(test.file) if err != nil { t.Fatalf("Unexpected error: %v", err) } defer f.Close() tr := NewReader(f) _, err = tr.Read([]byte{}) if err == nil || err != io.EOF { t.Errorf("Unexpected error: %v, wanted %v", err, io.EOF) } } type reader struct{ io.Reader } type readSeeker struct{ io.ReadSeeker } type readBadSeeker struct{ io.ReadSeeker } func (rbs *readBadSeeker) Seek(int64, int) (int64, error) { return 0, fmt.Errorf("illegal seek") } // TestReadTruncation test the ending condition on various truncated files and // that truncated files are still detected even if the underlying io.Reader // satisfies io.Seeker. func TestReadTruncation(t *testing.T) { var ss []string for _, p := range []string{ "testdata/gnu.tar", "testdata/ustar-file-reg.tar", "testdata/pax-path-hdr.tar", "testdata/sparse-formats.tar", } { buf, err := ioutil.ReadFile(p) if err != nil { t.Fatalf("unexpected error: %v", err) } ss = append(ss, string(buf)) } data1, data2, pax, sparse := ss[0], ss[1], ss[2], ss[3] data2 += strings.Repeat("\x00", 10*512) trash := strings.Repeat("garbage ", 64) // Exactly 512 bytes var vectors = []struct { input string // Input stream cnt int // Expected number of headers read err error // Expected error outcome }{ {"", 0, io.EOF}, // Empty file is a "valid" tar file {data1[:511], 0, io.ErrUnexpectedEOF}, {data1[:512], 1, io.ErrUnexpectedEOF}, {data1[:1024], 1, io.EOF}, {data1[:1536], 2, io.ErrUnexpectedEOF}, {data1[:2048], 2, io.EOF}, {data1, 2, io.EOF}, {data1[:2048] + data2[:1536], 3, io.EOF}, {data2[:511], 0, io.ErrUnexpectedEOF}, {data2[:512], 1, io.ErrUnexpectedEOF}, {data2[:1195], 1, io.ErrUnexpectedEOF}, {data2[:1196], 1, io.EOF}, // Exact end of data and start of padding {data2[:1200], 1, io.EOF}, {data2[:1535], 1, io.EOF}, {data2[:1536], 1, io.EOF}, // Exact end of padding {data2[:1536] + trash[:1], 1, io.ErrUnexpectedEOF}, {data2[:1536] + trash[:511], 1, io.ErrUnexpectedEOF}, {data2[:1536] + trash, 1, ErrHeader}, {data2[:2048], 1, io.EOF}, // Exactly 1 empty block {data2[:2048] + trash[:1], 1, io.ErrUnexpectedEOF}, {data2[:2048] + trash[:511], 1, io.ErrUnexpectedEOF}, {data2[:2048] + trash, 1, ErrHeader}, {data2[:2560], 1, io.EOF}, // Exactly 2 empty blocks (normal end-of-stream) {data2[:2560] + trash[:1], 1, io.EOF}, {data2[:2560] + trash[:511], 1, io.EOF}, {data2[:2560] + trash, 1, io.EOF}, {data2[:3072], 1, io.EOF}, {pax, 0, io.EOF}, // PAX header without data is a "valid" tar file {pax + trash[:1], 0, io.ErrUnexpectedEOF}, {pax + trash[:511], 0, io.ErrUnexpectedEOF}, {sparse[:511], 0, io.ErrUnexpectedEOF}, // TODO(dsnet): This should pass, but currently fails. // {sparse[:512], 0, io.ErrUnexpectedEOF}, {sparse[:3584], 1, io.EOF}, {sparse[:9200], 1, io.EOF}, // Terminate in padding of sparse header {sparse[:9216], 1, io.EOF}, {sparse[:9728], 2, io.ErrUnexpectedEOF}, {sparse[:10240], 2, io.EOF}, {sparse[:11264], 2, io.ErrUnexpectedEOF}, {sparse, 5, io.EOF}, {sparse + trash, 5, io.EOF}, } for i, v := range vectors { for j := 0; j < 6; j++ { var tr *Reader var s1, s2 string switch j { case 0: tr = NewReader(&reader{strings.NewReader(v.input)}) s1, s2 = "io.Reader", "auto" case 1: tr = NewReader(&reader{strings.NewReader(v.input)}) s1, s2 = "io.Reader", "manual" case 2: tr = NewReader(&readSeeker{strings.NewReader(v.input)}) s1, s2 = "io.ReadSeeker", "auto" case 3: tr = NewReader(&readSeeker{strings.NewReader(v.input)}) s1, s2 = "io.ReadSeeker", "manual" case 4: tr = NewReader(&readBadSeeker{strings.NewReader(v.input)}) s1, s2 = "ReadBadSeeker", "auto" case 5: tr = NewReader(&readBadSeeker{strings.NewReader(v.input)}) s1, s2 = "ReadBadSeeker", "manual" } var cnt int var err error for { if _, err = tr.Next(); err != nil { break } cnt++ if s2 == "manual" { if _, err = io.Copy(ioutil.Discard, tr); err != nil { break } } } if err != v.err { t.Errorf("test %d, NewReader(%s(...)) with %s discard: got %v, want %v", i, s1, s2, err, v.err) } if cnt != v.cnt { t.Errorf("test %d, NewReader(%s(...)) with %s discard: got %d headers, want %d headers", i, s1, s2, cnt, v.cnt) } } } }