normalizePath now always return absolute path, BasePathFs removes volume name from path

basepath.go

@@ -30,7 +30,9 @@ type BasePathFile struct {
 
 func (f *BasePathFile) Name() string {
 	sourcename := f.File.Name()
-	return strings.TrimPrefix(sourcename, filepath.Clean(f.path))
+	sourcename = strings.TrimPrefix(sourcename, filepath.VolumeName(sourcename))
+	sourcename = strings.TrimPrefix(sourcename, filepath.Clean(f.path))
+	return sourcename
 }
 
 func NewBasePathFs(source Fs, path string) Fs {

composite_test.go

@@ -479,7 +479,7 @@ func TestUnionFileReaddirAskForTooMany(t *testing.T) {
 	overlay := &MemMapFs{}
 
 	for i := 0; i < 5; i++ {
-		WriteFile(base, fmt.Sprintf("file%d.txt", i), []byte("afero"), 0777)
+		WriteFile(base, fmt.Sprintf("/file%d.txt", i), []byte("afero"), 0777)
 	}
 
 	ufs := &CopyOnWriteFs{base: base, layer: overlay}

memmap.go

@@ -191,7 +191,7 @@ func normalizePath(path string) (string, error) {
 	case FilePathSeparator:
 		return rootAbs, nil
 	default:
-		return path, nil
+		return filepath.Abs(path)
 	}
 }