fix: add gRPC nil/zero check in query (backport #13352) (#13417)

* fix: add gRPC nil/zero check in query (#13352)

(cherry picked from commit a9f02d9)

# Conflicts:
#	CHANGELOG.md
#	codec/proto_codec_test.go

* fix conflicts

* fix conflicts

Co-authored-by: yihuang <huang@crypto.com>

CHANGELOG.md

@@ -66,6 +66,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 * (export) [#13029](https://github.com/cosmos/cosmos-sdk/pull/13029) Fix exporting the blockParams regression.
 * [#13046](https://github.com/cosmos/cosmos-sdk/pull/13046) Fix missing return statement in BaseApp.Query.
 * (store) [#13336](https://github.com/cosmos/cosmos-sdk/pull/13336) Call streaming listeners for deliver tx event, it was removed accidentally, backport #13334.
+* (grpc) [#13417](https://github.com/cosmos/cosmos-sdk/pull/13417) fix grpc query panic that could crash the node (backport #13352).
 
 ## [v0.46.1](https://github.com/cosmos/cosmos-sdk/releases/tag/v0.46.1) - 2022-08-24
 

baseapp/grpcrouter_test.go

@@ -33,9 +33,9 @@ func TestGRPCQueryRouter(t *testing.T) {
 	require.NotNil(t, res)
 	require.Equal(t, "hello", res.Message)
 
-	require.Panics(t, func() {
-		_, _ = client.Echo(context.Background(), nil)
-	})
+	res, err = client.Echo(context.Background(), nil)
+	require.Nil(t, err)
+	require.Empty(t, res.Message)
 
 	res2, err := client.SayHello(context.Background(), &testdata.SayHelloRequest{Name: "Foo"})
 	require.Nil(t, err)
@@ -151,9 +151,9 @@ func testQueryDataRacesSameHandler(t *testing.T, makeClientConn func(*baseapp.GR
 			require.NotNil(t, res)
 			require.Equal(t, "hello", res.Message)
 
-			require.Panics(t, func() {
-				_, _ = client.Echo(context.Background(), nil)
-			})
+			res, err = client.Echo(context.Background(), nil)
+			require.Nil(t, err)
+			require.Empty(t, res.Message)
 
 			res2, err := client.SayHello(context.Background(), &testdata.SayHelloRequest{Name: "Foo"})
 			require.Nil(t, err)

codec/proto_codec.go

@@ -43,6 +43,11 @@ func NewProtoCodec(interfaceRegistry types.InterfaceRegistry) *ProtoCodec {
 // NOTE: this function must be used with a concrete type which
 // implements proto.Message. For interface please use the codec.MarshalInterface
 func (pc *ProtoCodec) Marshal(o ProtoMarshaler) ([]byte, error) {
+	// Size() check can catch the typed nil value.
+	if o == nil || o.Size() == 0 {
+		// return empty bytes instead of nil, because nil has special meaning in places like store.Set
+		return []byte{}, nil
+	}
 	return o.Marshal()
 }