@FILESIZE[] ... allocated ... unexpected results

[vefatica]

@FILESIZE[] doesn't get the allocated size right for files larger than 2^32-1. I'd guess it's not using 64-bit numbers (or not using them correctly). Below, the file size is 2^32+1 bytes.

v:\new> dir /k /m /h
2020-02-14  15:12       6,700,417  big.rnd
2020-02-14  15:15   4,294,967,297  bigger.rnd

v:\new> echo %@filesize[bigger.rnd,b,a]
4096