flatc is malfunction when java grpc and package prefix both enabled

[eeoun]

flatbuffers % flatc --java --grpc -o tdd --java-package-prefix com.github.flatbuffer tests/service_test.fbs

Result

flatbuffers % find tdd
tdd
tdd/example
tdd/example/HelloServiceGrpc.java
tdd/com
tdd/com/github
tdd/com/github/flatbuffer
tdd/com/github/flatbuffer/example
tdd/com/github/flatbuffer/example/HelloRequest.java
tdd/com/github/flatbuffer/example/HelloResponse.java

Expect:
HelloServiceGrpc.java Shoud in dir tdd/com/github/flatbuffer/example

and in content of HelloServiceGrpc.java all of extr_type input_type out_type lost prefix of package.

Looks like in .//src/idl_gen_grpc.cpp class JavaGRPCGenerator function generate LOC:424 forget to handle prefix name

NamespaceDir(*def->defined_namespace) + def->name + "Grpc.java";

and the same error
LOC:420

      p.package_name =
          def->defined_namespace->GetFullyQualifiedName("");  // file.package();

it shoulde append a prefix

parser.opts.java_package_prefix