Trigger sending server-side METHOD:REPLY when accepting an update iCalendar invitation
I receive an invitation as iMIP message. I Accept the invitation in Evolution. Evolution PUTs the ics file on the server and the server sends a METHOD=REPLY message to the organizer.
The organizer modifies the event, e.g. changes the timeslot, changes the Online-URL of the event. The server of the organizer triggers a new REQUEST, increasing the SEQUENCE and keeping the UID. Evolution recognizes this is an Update (displays the calendar which contains event with the same UID). I accept the re-invitation, evolution PUTs the event on the server.
My reading of RFC 5546 iCalendar Transport-Independent Interoperability Protocol and RFC 6047 iCalendar Message-Based Interoperability Protocol is that in such cases the server is not supposed to generate a new REPLY to the organizer. Either there is no text on this, or I do not find any special handling in the text on this use case. Thus the organizer does not know whether the participant has acknowledged the modified meeting (the new timeslot).
According to https://cyrus.topicbox.com/groups/devel/T6d8fa823698d54ca/generating-imip-on-putting-a-rescheduled-or-updated-event the proper way to tell the server to generate a REPLY to the organizer, when the attendee re-accepts a meeting with modified timeslot, is to insert SCHEDULE-FORCE-SEND=REPLY parameter to the ORGANIZER property prior to the PUT.
RFC 6638 - Forcing the Server to Send a Scheduling Message, RFC 6638 - Schedule Force Send Parameter.
My expectations are on accepting a RE-INVITE that the organizer is informed that I have acknowledged the changes. As it turns out protocol-wise the default behaviour is different from my expectations and the acknowledgement must be sent explicitly by other means.
- Extend Evolution to utilize the SCHEDULE-FORCE-SEND parameter