Protobuf: Compiled nested message definitions return wrong variable name

[wlwanpan]

Version: master/v3.5.0.
Language: Ruby
OS: macOS
Compiler: gcc

1. Add a nested message definition

message parent_msg
{
   message child_msg {}
}

1. Compile with flag --ruby_out

2. Result

Google::Protobuf::DescriptorPool.generated_pool.build do
    add_message "parent_msg" do
    end

    add_message "parent_msg.child_msg" do
    end
end

Parent_msg = Google::Protobuf::DescriptorPool.generated_pool.lookup("parent_msg").msgclass
parent_msg::Child_msg = Google::Protobuf::DescriptorPool.generated_pool.lookup("parent_msg.child_msg").msgclass

1. Error

undefined local variable or method `parent_msg' for main:Object

Expected

Parent_msg::Child_msg = Google::Protobuf::DescriptorPool.generated_pool.lookup("parent_msg.child_msg").msgclass

Got

parent_msg::Child_msg = Google::Protobuf::DescriptorPool.generated_pool.lookup("parent_msg.child_msg").msgclass

[TeBoring]

I'll have a fix for that.