TBSync might break event invites because of change of UID's - when sending and receiving

[xj25vm]

Thunderbird: 140.3.0 ESR TBSync: 4.16 Backend: Horde / Kronolith with ActiveSync OS: Windows 10 and Slackware Linux

When TBSync is installed at the sending end: when a calendar event is created in Thunderbird, it gets assigned a UID of format: 823ba2e7-de3c-4ffc-b2d2-8303fb589b81. If an invitation is sent immediately over email, the .ics file attached contains this UID. At the next TBSync run, TBSync updates the event UID to the format: [email protected]. Later on, if the event gets modified in anyway and an updated invitation is sent, the .ics file attached to the email will contain the second UID. The receiving end will not recognise the event update as applying to the original event, as it has a different UId, and will create a new event.

When TBSync runs at the receiving end, it breaks event invitations, but in a slightly different sequence. When receiving an event invitation over email from something like MS Teams or Zoom, Thunderbird will create a calendar event with the UID from the attached .ics file. Then at the next TBSync run, TBSync updates the UID. Then if the sender sends an event update, although the updated .ics file has the same UID as the original event invitation, Thunderbird doesn't recognise it applies to the correct event, as TBSync has changed the UID - so it creates a new event.

What I haven't been able to figure out is if TBSync takes the decision to change the UID - or if the back-end server generates the new UID - if anybody knows? I have asked at the Horde mailing list as well, just in case

Please let me know if further details are needed - but it should be fairly easy to test - as the .ics files sent out show quite clearly the change of UID.