@@ -160,7 +160,7 @@ func (daemon *Daemon) canDeleteImage(imgID string, force bool) error {

 			return err

 		}

-		if err := daemon.graph.WalkHistory(parent, func(p *image.Image) error {

+		if err := daemon.graph.WalkHistory(parent, func(p image.Image) error {

 			if imgID == p.ID {

 				if container.IsRunning() {

 					if force {

@@ -9,27 +9,13 @@ import (

 	"github.com/docker/docker/utils"

 )

-// History returns the list of all images used to create this image.

-func (graph *Graph) History(img *image.Image) ([]*image.Image, error) {

-	var parents []*image.Image

-	if err := graph.WalkHistory(img,

-		func(img *image.Image) error {

-			parents = append(parents, img)

-			return nil

-		},

-	); err != nil {

-		return nil, err

-	}

-	return parents, nil

-}

-

 // WalkHistory calls the handler function for each image in the

 // provided images lineage starting from immediate parent.

-func (graph *Graph) WalkHistory(img *image.Image, handler func(*image.Image) error) (err error) {

+func (graph *Graph) WalkHistory(img *image.Image, handler func(image.Image) error) (err error) {

 	currentImg := img

 	for currentImg != nil {

 		if handler != nil {

-			if err := handler(currentImg); err != nil {

+			if err := handler(*currentImg); err != nil {

 				return err

 			}

 		}

@@ -100,7 +86,7 @@ func (s *TagStore) History(name string) ([]*types.ImageHistory, error) {

 	history := []*types.ImageHistory{}

-	err = s.graph.WalkHistory(foundImage, func(img *image.Image) error {

+	err = s.graph.WalkHistory(foundImage, func(img image.Image) error {

 		history = append(history, &types.ImageHistory{

 			ID:        img.ID,

 			Created:   img.Created.Unix(),