Try fixing empty layer issue seen in lifecycle

Signed-off-by: Jesse Brown <jabrown85@gmail.com>

Author: jabrown85

remote/remote_test.go

@@ -570,6 +570,11 @@ func testImage(t *testing.T, when spec.G, it spec.S) {
 				h.AssertNil(t, err)
 				h.AssertNil(t, image.Save())
 				h.AssertEq(t, len(h.FetchManifestLayers(t, repoName)), 1)
+
+				// Pull the image via Docker to verify it works with containerd-snapshotter
+				dockerClient := h.DockerCli(t)
+				h.PullIfMissing(t, dockerClient, repoName)
+				defer h.DockerRmi(dockerClient, repoName)
 			})
 		})
 

remote/save.go

@@ -16,7 +16,9 @@ func (i *Image) Save(additionalNames ...string) error {
 }
 
 var (
-	emptyLayer   = static.NewLayer([]byte{}, types.OCILayer)
+	// An empty tar archive is two 512-byte zero blocks (EOF markers).
+	// Zero-byte content is rejected by containerd-snapshotter.
+	emptyLayer   = static.NewLayer(make([]byte, 1024), types.OCILayer)
 	emptyHistory = v1.History{Created: v1.Time{Time: imgutil.NormalizedDateTime}}
 )