@@ -55,12 +55,9 @@ func (cli *Client) ServiceCreate(ctx context.Context, service swarm.ServiceSpec,

 // the image string if it didn't originally contain a digest. It assumes

 // that the image string is not an image ID

 func imageWithDigestString(image string, dgst digest.Digest) string {

-	isCanonical := false

 	ref, err := reference.ParseAnyReference(image)

 	if err == nil {

-		_, isCanonical = ref.(reference.Canonical)

-

-		if !isCanonical {

+		if _, isCanonical := ref.(reference.Canonical); !isCanonical {

 			namedRef, _ := ref.(reference.Named)

 			img, err := reference.WithDigest(namedRef, dgst)

 			if err == nil {