Bug in $$ItemSerial TDL function

Tally Integration using RTSlink DLL

$$ItemSerial [TDL function]

"The function $ItemSerial generates Line numbers beginning from 0. It does not accept any parameter and returns Numerical value. "

Using $ItemSerial function with Masters

SELECT $$ItemSerial,$Name FROM Ledger

Remarks:-
The $$ItemSerial works fine when used with any MASTER's Collection like LEDGER, GROUP,STOCKITEM etc. However, it returns random (incorrect) values when used with VOUCHER object as shown below.

Using $$ItemSerial function with Vouchers

SELECT $$ItemSerial, $Date, $VoucherTypeName, FROM RTSAllVouchers

Remarks:-
1) When you use the above SELECT statement, the $$ItemSerial function returns random values and not the line serial number starting from 0 as in case of MASTERs.

2) RTSAllVouchers is a user-defined collection and its TDL code has been provided in my earlier post.

BUG:
It has been confirmed by Tally Solutions, Bangalore that the $$ItemSerial function generates (incorrect) random values when used with the VOUCHER object.

Please note that both Tally 7.2 and Tally 9 have the $$ItemSerial bug.