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

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()
 }