c8d/pull: Fix stale Downloading progress

Final progress messages were sent after the progress updater finished
which made the "Downloading" progress not being updated into "Download
complete".

Fix by sending the final messages after the progress has finished.

Signed-off-by: Paweł Gronowski <pawel.gronowski@docker.com>

daemon/containerd/image_pull.go

@@ -51,7 +51,26 @@ func (i *ImageService) PullImage(ctx context.Context, ref reference.Named, platf
 	out := streamformatter.NewJSONProgressOutput(outStream, false)
 	pp := pullProgress{store: i.client.ContentStore(), showExists: true}
 	finishProgress := jobs.showProgress(ctx, out, pp)
-	defer finishProgress()
+
+	var outNewImg *containerd.Image
+	defer func() {
+		finishProgress()
+
+		// Send final status message after the progress updater has finished.
+		// Otherwise the layer/manifest progress messages may arrive AFTER the
+		// status message have been sent, so they won't update the previous
+		// progress leaving stale progress like:
+		// 70f5ac315c5a: Downloading [>       ]       0B/3.19kB
+		// Digest: sha256:4f53e2564790c8e7856ec08e384732aa38dc43c52f02952483e3f003afbf23db
+		// 70f5ac315c5a: Download complete
+		// Status: Downloaded newer image for hello-world:latest
+		// docker.io/library/hello-world:latest
+		if outNewImg != nil {
+			img := *outNewImg
+			progress.Message(out, "", "Digest: "+img.Target().Digest.String())
+			writeStatus(out, reference.FamiliarString(ref), old.Digest != img.Target().Digest)
+		}
+	}()
 
 	var sentPullingFrom, sentSchema1Deprecation bool
 	ah := images.HandlerFunc(func(ctx context.Context, desc ocispec.Descriptor) ([]ocispec.Descriptor, error) {
@@ -108,9 +127,6 @@ func (i *ImageService) PullImage(ctx context.Context, ref reference.Named, platf
 		"remote": ref.String(),
 	})
 	logger.Info("image pulled")
-	progress.Message(out, "", "Digest: "+img.Target().Digest.String())
-
-	writeStatus(out, reference.FamiliarString(ref), old.Digest != img.Target().Digest)
 
 	// The pull succeeded, so try to remove any dangling image we have for this target
 	err = i.client.ImageService().Delete(context.Background(), danglingImageName(img.Target().Digest))
@@ -121,7 +137,7 @@ func (i *ImageService) PullImage(ctx context.Context, ref reference.Named, platf
 	}
 
 	i.LogImageEvent(reference.FamiliarString(ref), reference.FamiliarName(ref), events.ActionPull)
-
+	outNewImg = &img
 	return nil
 }