@@ -108,7 +108,9 @@ func TarFilter(path string, compression Compression, filter []string) (io.Reader

 //  identity (uncompressed), gzip, bzip2, xz.

 // FIXME: specify behavior when target path exists vs. doesn't exist.

 func Untar(archive io.Reader, path string) error {

-

+	if archive == nil {

+		return fmt.Errorf("Empty archive")

+	}

 	bufferedArchive := bufio.NewReaderSize(archive, 10)

 	buf, err := bufferedArchive.Peek(10)

 	if err != nil {

@@ -92,9 +92,11 @@ func StoreImage(img *Image, layerData Archive, root string, store bool) error {

 		defer file.Close()

 		layerData = file

 	}

-

-	if err := Untar(layerData, layer); err != nil {

-		return err

+	// If layerData is not nil, unpack it into the new layer

+	if layerData != nil {

+		if err := Untar(layerData, layer); err != nil {

+			return err

+		}

 	}

 	return StoreSize(img, root)