bug: event is raising "only contains modifications" error

[fabien-michel]

The following event is raising a only contains modifications error

It is generated by google calendar. In fact I got a lot of them from google calendars.

I'm not sure it is a legitimate error, but maybe I do not understand something.

BEGIN:VEVENT
SUMMARY:XXX
DTSTART;TZID=Europe/Paris:20210128T103000
DTEND;TZID=Europe/Paris:20210128T123000
DTSTAMP:20240905T100311Z
UID:[email protected]
RECURRENCE-ID;TZID=Europe/Paris:20210128T103000
SEQUENCE:2
ATTENDEE;[email protected];CUTYPE=INDIVIDUAL;PARTSTAT=NEEDS
 -ACTION;ROLE=REQ-PARTICIPANT;X-NUM-GUESTS=0:mailto:[email protected]
ATTENDEE;[email protected];CUTYPE=INDIVIDUAL;PARTSTAT=ACCEPTE
 D;ROLE=REQ-PARTICIPANT;X-NUM-GUESTS=0:mailto:[email protected]
ATTENDEE;[email protected];CUTYPE=INDIVIDUAL;PARTSTAT=ACC
 EPTED;ROLE=REQ-PARTICIPANT;X-NUM-GUESTS=0:mailto:[email protected]
ATTENDEE;[email protected];CUTYPE=INDIVIDUAL;PARTSTAT=ACCEP
 TED;ROLE=REQ-PARTICIPANT;X-NUM-GUESTS=0:mailto:[email protected]
ATTENDEE;[email protected];CUTYPE=INDIVIDUAL;PARTSTAT=NEEDS-AC
 TION;ROLE=REQ-PARTICIPANT;X-NUM-GUESTS=0:mailto:[email protected]
CREATED:20201217T141214Z
DESCRIPTION:XXX
LAST-MODIFIED:20230121T015157Z
ORGANIZER;[email protected]:mailto:[email protected]
STATUS:CONFIRMED
TRANSP:OPAQUE
END:VEVENT

[niccokunzmann]

Hi, thanks for reporting this! Could you attach the whole ICS file for this? Is there an ICS file or is it only this event?

[fabien-michel]

Here is a full ics from google calendar (anonymized) which trigger the error

only_modifications_error.ics.zip

recurring_ical_events.OnlyModificationsEvent: The event definition for _6krj2dhl74q34b9j60sj4b9k8h238b9p6gok2ba68gojgchl6cpj0h1o88_R20231009T130000@google.com only contains modifications.: _6krj2dhl74q34b9j60sj4b9k8h238b9p6gok2ba68gojgchl6cpj0h1o88_R20231009T130000@google.com

[niccokunzmann]

Thanks!

[niccokunzmann]

Quoting #172 (comment)

... If we have an event series and it does not have a 'core' event but only recurrences specified, we could assume that these recurrences should be part of the results. [...] we would incorporate those into the event series. [...]

If Google Calendar creates these events, I wonder what is meant by that. Do they turn up in the online calendar?
Do you see an event at 2021 Jan 28 at 10:30 (Paris Time) in the calendar? I will check the RFC...

[AttilaPazmandi]

Hi,

I have the same problem

BEGIN:VEVENT
DESCRIPTION:<...>\n______________________________________________________
__________________________\n\n
UID:040000008200E00074C5B7101A82E00800000000401FEA87490EDA01000000000000000
010000000F9112D922FE20E4DB34316608DEC223F
RECURRENCE-ID;TZID=W. Europe Standard Time:20231116T100000
SUMMARY:<Title>
DTSTART;TZID=W. Europe Standard Time:20231128T100000
DTEND;TZID=W. Europe Standard Time:20231128T110000
CLASS:PUBLIC
PRIORITY:5
DTSTAMP:20240909T121901Z
TRANSP:OPAQUE
STATUS:CONFIRMED
SEQUENCE:10
LOCATION:Microsoft Teams Meeting
X-MICROSOFT-CDO-APPT-SEQUENCE:10
X-MICROSOFT-CDO-BUSYSTATUS:TENTATIVE
X-MICROSOFT-CDO-INTENDEDSTATUS:BUSY
X-MICROSOFT-CDO-ALLDAYEVENT:FALSE
X-MICROSOFT-CDO-IMPORTANCE:1
X-MICROSOFT-CDO-INSTTYPE:3
X-MICROSOFT-DONOTFORWARDMEETING:FALSE
X-MICROSOFT-DISALLOW-COUNTER:FALSE
X-MICROSOFT-REQUESTEDATTENDANCEMODE:DEFAULT
X-MICROSOFT-ISRESPONSEREQUESTED:FALSE
END:VEVENT

It throws the following:
File "/usr/local/lib/python3.12/site-packages/recurring_ical_events.py", line 335, in __init__ raise InvalidCalendar( recurring_ical_events.InvalidCalendar: The event definition for 040000008200E00074C5B7101A82E00800000000401FEA87490EDA01000000000000000010000000F9112D922FE20E4DB34316608DEC223F only contains modifications.
It is visible in my calendar on the 28th of November, 2023 at 10AM.

[niccokunzmann]

@AttilaPazmandi, could you also attach an ICS file?

[niccokunzmann]

For this issue, I would not skip the events. I believe that it can happen e.g. if you accept a calendar invitation with a recurring event. Thus, the event should be included in the results.
The error here is more part of the assumptions I made during the creation of the algorithm.

[fabien-michel]

Thanks, all our calendars previously crashing on it, now pass !