The parser must be able to handle absent values in input and translate that into null as required. I see several tickets on this matter in the history, but none seem to have addressed the issue, at least not for parsing.
For this problem, I see a need to introduce a new term:
Definition: Absent value is when there are zero characters between field delimiters.
Specifically the aim is to be able to parse the following:
CSV-93 which I think never addressed the issue, probably because the reporter was happy with having the issue fixed for CSV output, not for parsing.
A PR is coming...