w.errh(err)
		return
	}

	// apply pkgh to the files in directory dir

	// Don't get test files as these packages are imported.
	pkgFiles, err := pkgFilenames(dir, false)
	if err != nil {
		w.errh(err)
		return
	}
	if pkgFiles != nil {
		w.pkgh(dir, pkgFiles)
	}

	// traverse subdirectories, but don't walk into testdata
	for _, f := range files {
		if f.IsDir() && f.Name() != "testdata" {