At the moment, we're supporting SIP 2.0 for the 63 Patron Information Request, but the 3M SIP2 Protocol Extensions outlines a 7th position "fee items". If a SIP2 client sents a Y in that position, Koha will close the connection. At the very least, it should just return a 64 response and just not send any fee item info back.
Created attachment 111011 [details] SIP2 Protocol Extensions
After a bit more review, it looks like Koha is silently getting a fatal error, and then closes the connection. While we don't need to support the SIP2 Protocol Extension, I think we should continue to work. Looking at the SIP2 server code, it's just badly written code, which makes too many assumptions.
Is this a duplicate of bug 36752?