How fix Palo 3.2 bug dateformat- return empty data?

    How fix Palo 3.2 bug dateformat- return empty data?

    Hi Sir/Madam,
    I know there was a bug leaving in Palo 3.x (open source version), and fixed in Palo 3.3 (perimum version)- dateformat returns empty data while setting rules.
    I try to fix the bug by myself and find these is no any source code was written under VirtualMachine.cpp case FUNC_DATEFORMAT. Therefore, it is obvious that Palo returns empty data caused by it. Now, I try to add one line and call a function under Func_dateformat as the code below. It works fine, but I face another problem. Palo returns empty data sometimes in simple cube rule linking like palo.data() which is no dateformat function inside the rule. I can not find the problem & root cause. Do I miss anything under Func_Dateformat? I am Java program, and not familiar with C++. Any advice are highly appreciated. =O

    case bytecode_generator::FUNC_DATEFORMAT: /* S <- D,S */ str_0 = palo::FunctionNodeDateformat::Format(dbl_0, str_0);