Merge pull request moby#5406 from jsternberg/client-nil-reference

grpcclient: return proper nil reference from grpcclient

Author: tonistiigi

frontend/dockerfile/dockerfile_test.go

@@ -196,6 +196,7 @@ var allTests = integration.TestFuncs(
 	testCommandSourceMapping,
 	testSBOMScannerArgs,
 	testNilContextInSolveGateway,
+	testMultiNilRefsInSolveGateway,
 	testCopyUnicodePath,
 	testFrontendDeduplicateSources,
 	testDuplicateLayersProvenance,
@@ -8297,6 +8298,41 @@ func testNilContextInSolveGateway(t *testing.T, sb integration.Sandbox) {
 	require.ErrorContains(t, err, "invalid nil input definition to definition op")
 }
 
+func testMultiNilRefsInSolveGateway(t *testing.T, sb integration.Sandbox) {
+	workers.CheckFeatureCompat(t, sb, workers.FeatureMultiPlatform)
+	ctx := sb.Context()
+
+	c, err := client.New(ctx, sb.Address())
+	require.NoError(t, err)
+	defer c.Close()
+
+	f := getFrontend(t, sb)
+
+	_, err = c.Build(sb.Context(), client.SolveOpt{}, "", func(ctx context.Context, c gateway.Client) (*gateway.Result, error) {
+		localDockerfile, err := llb.Scratch().
+			File(llb.Mkfile("Dockerfile", 0644, []byte(`FROM scratch`))).
+			Marshal(ctx)
+		if err != nil {
+			return nil, err
+		}
+
+		res, err := f.SolveGateway(ctx, c, gateway.SolveRequest{
+			Frontend: "dockerfile.v0",
+			FrontendOpt: map[string]string{
+				"platform": "linux/amd64,linux/arm64",
+			},
+			FrontendInputs: map[string]*pb.Definition{
+				dockerui.DefaultLocalNameDockerfile: localDockerfile.ToPB(),
+			},
+		})
+		if err != nil {
+			return nil, err
+		}
+		return res, nil
+	}, nil)
+	require.NoError(t, err)
+}
+
 func testCopyUnicodePath(t *testing.T, sb integration.Sandbox) {
 	f := getFrontend(t, sb)
 	c, err := client.New(sb.Context(), sb.Address())

frontend/gateway/grpcclient/client.go

@@ -429,28 +429,21 @@ func (c *grpcClient) Solve(ctx context.Context, creq client.SolveRequest) (res *
 			}
 		case *pb.Result_RefsDeprecated:
 			for k, v := range pbRes.RefsDeprecated.Refs {
-				ref := &reference{id: v, c: c}
-				if v == "" {
-					ref = nil
+				var ref client.Reference
+				if v != "" {
+					ref = &reference{id: v, c: c}
 				}
 				res.AddRef(k, ref)
 			}
 		case *pb.Result_Ref:
 			if pbRes.Ref.Id != "" {
-				ref, err := newReference(c, pbRes.Ref)
-				if err != nil {
-					return nil, err
-				}
-				res.SetRef(ref)
+				res.SetRef(newReference(c, pbRes.Ref))
 			}
 		case *pb.Result_Refs:
 			for k, v := range pbRes.Refs.Refs {
-				var ref *reference
+				var ref client.Reference
 				if v.Id != "" {
-					ref, err = newReference(c, v)
-					if err != nil {
-						return nil, err
-					}
+					ref = newReference(c, v)
 				}
 				res.AddRef(k, ref)
 			}
@@ -464,11 +457,7 @@ func (c *grpcClient) Solve(ctx context.Context, creq client.SolveRequest) (res *
 						return nil, err
 					}
 					if a.Ref.Id != "" {
-						ref, err := newReference(c, a.Ref)
-						if err != nil {
-							return nil, err
-						}
-						att.Ref = ref
+						att.Ref = newReference(c, a.Ref)
 					}
 					res.AddAttestation(p, *att)
 				}
@@ -1168,8 +1157,8 @@ type reference struct {
 	def *opspb.Definition
 }
 
-func newReference(c *grpcClient, ref *pb.Ref) (*reference, error) {
-	return &reference{c: c, id: ref.Id, def: ref.Def}, nil
+func newReference(c *grpcClient, ref *pb.Ref) *reference {
+	return &reference{c: c, id: ref.Id, def: ref.Def}
 }
 
 func (r *reference) ToState() (st llb.State, err error) {