func TestFSWalk(t *testing.T) {
	for _, test := range []struct {
		file    string
		want    []string
		wantErr bool
	}{
		{
			file: "testdata/unix.zip",
			want: []string{".", "dir", "dir/bar", "dir/empty", "hello", "readonly"},
		},
		{
			file: "testdata/subdir.zip",
			want: []string{".", "a", "a/b", "a/b/c"},
		},
		{
			file:    "testdata/dupdir.zip",
			wantErr: true,
		},

	if usePkgCache {
		if tags, ok := pkgTags[dir]; ok {
			key = tagKey(dir, context, tags)
			if pkg := pkgCache[key]; pkg != nil {
				w.imported[name] = pkg
				return pkg, nil
			}
		}
	}

	info, err := context.ImportDir(dir, 0)
	if err != nil {
		if _, nogo := err.(*build.NoGoError); nogo {
			return nil, err
		}
		log.Fatalf("pkg %q, dir %q: ScanDir: %v", name, dir, err)
	}

// CreateHeader and CreateRaw.
func (w *Writer) prepare(fh *FileHeader) error {
	if w.last != nil && !w.last.closed {
		if err := w.last.close(); err != nil {
			return err
		}
	}
	if len(w.dir) > 0 && w.dir[len(w.dir)-1].FileHeader == fh {
		// See https://golang.org/issue/11144 confusion.
		return errors.New("archive/zip: invalid duplicate FileHeader")
	}
	return nil
}

			Mode:     0660,
			Size:     0,
			ModTime:  time.Unix(1360578954, 0),
			Typeflag: TypeBlock,
		},
		fm: 0660 | fs.ModeDevice,
	}, {
		// directory.
		h: &Header{
			Name:     "dir/",
			Mode:     0755,
			Size:     0,
			ModTime:  time.Unix(1360601116, 0),
			Typeflag: TypeDir,
		},
		fm: 0755 | fs.ModeDir,
	}, {
		// fifo node.
		h: &Header{
			Name:     "dev/initctl",