POSIX and Windows may interpret directory document whitespace differently
on Windows, _atoi64 defines whitespace as: A whitespace consists of space or tab characters https://msdn.microsoft.com/en-us/library/czcad93k.aspx
But on POSIX-derived platforms, stroul* define whitespace as isspace(), which is: \t \n \v \f \r " "
This affects at least tor_parse_uint64, and perhaps other functions.
It could mean that some numbers are interpreted differently by Windows and POSIX platforms, but since dir-spec.txt defines whitespace as space or tab, this is unlikely.