// and a non-nil error.
//
// Most clients are better served by the more efficient ReadDir method.
func (f *File) Readdir(n int) ([]FileInfo, error) {
	if f == nil {
		return nil, ErrInvalid
	}
	_, _, infos, err := f.readdir(n, readdirFileInfo)
	if infos == nil {
		// Readdir has historically always returned a non-nil empty slice, never nil,
		// even on error (except misuse with nil receiver above).

		return 0, &fs.PathError{Op: "seek", Path: f.path, Err: fs.ErrInvalid}
	}
	f.offset = offset
	return offset, nil
}

func (f *openMapFile) ReadAt(b []byte, offset int64) (int, error) {
	if offset < 0 || offset > int64(len(f.f.Data)) {
		return 0, &fs.PathError{Op: "read", Path: f.path, Err: fs.ErrInvalid}
	}
	n := copy(b, f.f.Data[offset:])
	if n < len(b) {
		return n, io.EOF
	}

	if kubeConfigDir == "" {
		return errors.Errorf("%s: kubeConfigDir was empty", errInvalid)
	}
	if kubeadmConfig == nil {
		return errors.Errorf("%s: kubeadmConfig was nil", errInvalid)
	}
	if name == "" {
		return errors.Errorf("%s: name was empty", errInvalid)
	}
	if spec == nil {
		return errors.Errorf("%s: spec was nil", errInvalid)
	}
	kubeConfigPath := filepath.Join(kubeConfigDir, name)

type failPermFS struct{}

func (f failPermFS) Open(name string) (fs.File, error) {
	if !fs.ValidPath(name) {
		return nil, &fs.PathError{Op: "open", Path: name, Err: fs.ErrInvalid}
	}
	return nil, &fs.PathError{Op: "open", Path: name, Err: fs.ErrPermission}
}

func TestTestFSWrappedErrors(t *testing.T) {
	err := TestFS(failPermFS{})
	if err == nil {
		t.Fatal("error expected")
	}

func (p *Process) kill() error {
	return p.signal(Kill)
}

func (p *Process) wait() (ps *ProcessState, err error) {
	var waitmsg syscall.Waitmsg

	switch p.pidStatus() {
	case statusReleased:
		return nil, ErrInvalid
	}

	err = syscall.WaitProcess(p.Pid, &waitmsg)
	if err != nil {
		return nil, NewSyscallError("wait", err)
	}

	p.pidDeactivate(statusDone)
	ps = &ProcessState{
		pid:    waitmsg.Pid,

		return 0, &fs.PathError{Op: "seek", Path: f.f.name, Err: fs.ErrInvalid}
	}
	f.offset = offset
	return offset, nil
}

func (f *openFile) ReadAt(b []byte, offset int64) (int, error) {
	if offset < 0 || offset > int64(len(f.f.data)) {
		return 0, &fs.PathError{Op: "read", Path: f.f.name, Err: fs.ErrInvalid}
	}
	n := copy(b, f.f.data[offset:])
	if n < len(b) {
		return n, io.EOF
	}

	stopFn := globalSftpMetrics.log(r, f.AccessKey())
	defer stopFn(0, err)

	flags := r.Pflags()
	if !flags.Read {
		// sanity check
		return nil, os.ErrInvalid
	}

	bucket, object := path2BucketObject(r.Filepath)
	if bucket == "" {
		return nil, errors.New("bucket name cannot be empty")
	}

	clnt, err := f.getMinIOClient()
	if err != nil {

				gzip.ErrHeader, gzip.ErrChecksum,
				s2.ErrCorrupt, s2.ErrUnsupported, s2.ErrCRC,
				zstd.ErrBlockTooSmall, zstd.ErrMagicMismatch, zstd.ErrWindowSizeExceeded, zstd.ErrUnknownDictionary, zstd.ErrWindowSizeTooSmall,
				lz4.ErrInvalid, lz4.ErrBlockDependency,
			}
			for _, e := range errs {
				if errors.Is(err, e) {
					return errInvalidCompression(err, s3Select.Input.CompressionType)
				}
			}
			return err
		}
		return nil

}

// Test that all File methods give ErrInvalid if the receiver is nil.
func TestNilFileMethods(t *testing.T) {
	t.Parallel()

	for _, tt := range nilFileMethodTests {
		var file *File
		got := tt.f(file)
		if got != ErrInvalid {
			t.Errorf("%v should fail when f is nil; got %v", tt.name, got)
		}
	}
}

func (f *fakeFile) Close() error               { return nil }
func (f *fakeFile) Stat() (fs.FileInfo, error) { return f.fi, nil }
func (f *fakeFile) Readdir(count int) ([]fs.FileInfo, error) {
	if !f.fi.dir {
		return nil, fs.ErrInvalid
	}
	var fis []fs.FileInfo

	limit := f.entpos + count
	if count <= 0 || limit > len(f.fi.ents) {
		limit = len(f.fi.ents)
	}
	for ; f.entpos < limit; f.entpos++ {