// result: we want to preserve the exact dir prefix from the environment.
		sep := string(filepath.Separator)
		if os.IsPathSeparator(dir[len(dir)-1]) {
			sep = ""
		}

		if searchExt {
			ents, err := os.ReadDir(dir)
			if err != nil {
				continue
			}
			for _, ent := range ents {
				for _, ext := range pathExt {
					if !ent.IsDir() && strEqual(ent.Name(), command+ext) {
						return dir + sep + ent.Name(), nil

	}
	return asString(s[n : n+int(v)])
}

// A reader reads sequential fields from a section of the index format.
type reader struct {
	d   *decoder
	pos int
}

// readAt returns a reader starting at the given position in d.
func (d *decoder) readAt(pos int) *reader {
	return &reader{d, pos}
}

// int reads the next int.
func (r *reader) int() int {
	i := r.d.intAt(r.pos)
	r.pos += 4

	alreadyTested := sets.New[string]()
	for _, t := range cases {
		if t.want != "" {
			alreadyTested.Insert(t.want)
		} else {
			alreadyTested.Insert(t.in + ".injected")
		}
	}
	files, err := os.ReadDir("testdata/inject")
	if err != nil {
		t.Fatal(err)
	}
	if len(files) < 3 {
		t.Fatalf("Didn't find test files - something must have gone wrong")
	}

				t.Fatalf("file is changed!")
			}
		}
	}
}

func filenames(t *testing.T, dir string) []string {
	t.Helper()
	res := []string{}
	contents, err := os.ReadDir(dir)
	if err != nil {
		t.Fatal(err)
	}
	for _, f := range contents {
		res = append(res, f.Name())
	}
	sort.Strings(res)
	return res
}

pkg os, func OpenFile(string, int, FileMode) (*File, error)
pkg os, func SameFile(FileInfo, FileInfo) bool
pkg os, func Stat(string) (FileInfo, error)
pkg os, method (*File) Chmod(FileMode) error
pkg os, method (*File) Readdir(int) ([]FileInfo, error)
pkg os, method (*File) Stat() (FileInfo, error)
pkg os, method (*PathError) Error() string
pkg os, method (*PathError) Timeout() bool
pkg os, method (*PathError) Unwrap() error

	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) {

	realTmpDir, err := filepath.EvalSymlinks(tmpDir)
	if err != nil {
		t.Fatal(err)
	}
	realDir := filepath.Join(realTmpDir, "dir")
	realFile := filepath.Join(realDir, "file")

	tests := []struct {
		path, want string
	}{
		{dir, realDir},
		{linkToDir, realDir},
		{file, realFile},
		{link1, realFile},
		{link2, realFile},
	}
	for i, test := range tests {

// be saved in a MalformedCorpusError and returned, along with the most recent
// error.
func ReadCorpus(dir string, types []reflect.Type) ([]CorpusEntry, error) {
	files, err := os.ReadDir(dir)
	if os.IsNotExist(err) {
		return nil, nil // No corpus to read
	} else if err != nil {
		return nil, fmt.Errorf("reading seed corpus from testdata: %v", err)
	}
	var corpus []CorpusEntry
	var errs []error

}

func mustReadfolder(t *testing.T, folder string) string {
	result := ""
	fpathRoot := folder
	if !strings.HasPrefix(fpathRoot, ".") {
		fpathRoot = filepath.Join(env.IstioSrc, folder)
	}
	f, err := os.ReadDir(fpathRoot)
	if err != nil {
		t.Fatal(err)
	}
	for _, fpath := range f {
		bytes, err := os.ReadFile(filepath.Join(fpathRoot, fpath.Name()))
		if err != nil {
			t.Fatal(err)
		}
		result += "---\n"

// AST reader

// reader accumulates documentation for a single package.
// It modifies the AST: Comments (declaration documentation)
// that have been collected by the reader are set to nil
// in the respective AST nodes so that they are not printed
// twice (once when printing the documentation and once when
// printing the corresponding AST node).
type reader struct {
	mode Mode