@@ -137,7 +137,7 @@ func (gdw *NaiveDiffDriver) ApplyDiff(id, parent string, diff io.Reader) (size i

 	// Mount the root filesystem so we can apply the diff/layer.

 	layerRootFs, err := driver.Get(id, "")

 	if err != nil {

-		return

+		return 0, err

 	}

 	defer driver.Put(id)

@@ -145,28 +145,28 @@ func (gdw *NaiveDiffDriver) ApplyDiff(id, parent string, diff io.Reader) (size i

 	options := &archive.TarOptions{IDMap: gdw.IDMap, BestEffortXattrs: gdw.BestEffortXattrs}

 	start := time.Now().UTC()

 	log.G(context.TODO()).WithField("id", id).Debug("Start untar layer")

-	if size, err = ApplyUncompressedLayer(layerFs, diff, options); err != nil {

-		return

+	appliedSize, err := ApplyUncompressedLayer(layerFs, diff, options)

+	if err != nil {

+		return 0, err

 	}

 	log.G(context.TODO()).WithField("id", id).Debugf("Untar time: %vs", time.Now().UTC().Sub(start).Seconds())

-

-	return

+	return appliedSize, nil

 }

 // DiffSize calculates the changes between the specified layer

 // and its parent and returns the size in bytes of the changes

 // relative to its base filesystem directory.

-func (gdw *NaiveDiffDriver) DiffSize(id, parent string) (size int64, err error) {

+func (gdw *NaiveDiffDriver) DiffSize(id, parent string) (size int64, _ error) {

 	driver := gdw.ProtoDriver

 	changes, err := gdw.Changes(id, parent)

 	if err != nil {

-		return

+		return 0, err

 	}

 	layerFs, err := driver.Get(id, "")

 	if err != nil {

-		return

+		return 0, err

 	}

 	defer driver.Put(id)