bug: EXDATE does not work for event with higher SEQUENCE

[zoifar]

Describe the bug

EXDATE does not exclude an instance for an event with higher SEQUENCE and the same UID.

To Reproduce

ical_string="""BEGIN:VCALENDAR
BEGIN:VEVENT
DTSTAMP:20240707T214014Z
DTSTART;VALUE=DATE:20240701
DTEND;VALUE=DATE:20240708
SUMMARY:test123
CATEGORIES:other
UID:111
ORGANIZER:aaa
RRULE:FREQ=WEEKLY;UNTIL=20240801;INTERVAL=2;BYDAY=MO
CREATED:20240311T051101Z
LAST-MODIFIED:20240311T051101Z
SEQUENCE:1
END:VEVENT

BEGIN:VEVENT
DTSTAMP:20240707T214014Z
DTSTART;VALUE=DATE:20240701
DTEND;VALUE=DATE:20240708
SUMMARY:test123
CATEGORIES:other
UID:111
ORGANIZER:aaa
RRULE:FREQ=WEEKLY;UNTIL=20240801;INTERVAL=2;BYDAY=MO
EXDATE;VALUE=DATE:20240715
CREATED:20240311T051101Z
LAST-MODIFIED:20240701T063743Z
SEQUENCE:2
END:VEVENT
END:VCALENDAR"""
calendar = icalendar.Calendar.from_ical(ical_string)
events=recurring_ical_events.of(calendar).at(2024)

for event in events:
    start = event["DTSTART"].dt
    duration = event["DTEND"].dt - event["DTSTART"].dt
    print("start {} duration {}".format(start, duration))

ICS file

BEGIN:VCALENDAR
BEGIN:VEVENT
DTSTAMP:20240707T214014Z
DTSTART;VALUE=DATE:20240701
DTEND;VALUE=DATE:20240708
SUMMARY:test123
CATEGORIES:other
UID:111
ORGANIZER:aaa
RRULE:FREQ=WEEKLY;UNTIL=20240801;INTERVAL=2;BYDAY=MO
CREATED:20240311T051101Z
LAST-MODIFIED:20240311T051101Z
SEQUENCE:1
END:VEVENT

BEGIN:VEVENT
DTSTAMP:20240707T214014Z
DTSTART;VALUE=DATE:20240701
DTEND;VALUE=DATE:20240708
SUMMARY:test123
CATEGORIES:other
UID:111
ORGANIZER:aaa
RRULE:FREQ=WEEKLY;UNTIL=20240801;INTERVAL=2;BYDAY=MO
EXDATE;VALUE=DATE:20240715
CREATED:20240311T051101Z
LAST-MODIFIED:20240701T063743Z
SEQUENCE:2
END:VEVENT
END:VCALENDAR

Expected behavior

only events from SEQUENCE:2 are returned:

start 2024-07-01 duration 7 days, 0:00:00
start 2024-07-29 duration 7 days, 0:00:00

Console output

start 2024-07-15 duration 7 days, 0:00:00
start 2024-07-01 duration 7 days, 0:00:00
start 2024-07-29 duration 7 days, 0:00:00

Version:

2.2.1

Additional context

This is generated by atlassian confluence calendar when multiple instances of an event are modified.

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[niccokunzmann]

Thanks! This is a nice catch of an edge case!

[niccokunzmann]

For more edge cases:

• EDGE CASE 1 What does the confluence calendar do when the following is imported:

1. event made (3x, each 2 weeks)
2. event in middle moved
3. base event edited

import icalendar, recurring_ical_events
ical_string="""BEGIN:VCALENDAR
BEGIN:VEVENT
DTSTAMP:20240707T214014Z
DTSTART;VALUE=DATE:20240701
DTEND;VALUE=DATE:20240708
SUMMARY:test123
CATEGORIES:other
UID:111
ORGANIZER:aaa
RRULE:FREQ=WEEKLY;UNTIL=20240801;INTERVAL=2;BYDAY=MO
CREATED:20240311T051101Z
LAST-MODIFIED:20240311T051101Z
SEQUENCE:1
END:VEVENT
BEGIN:VEVENT
RECURRENCE-ID;VALUE=DATE:20240715
DTSTAMP:20240707T214014Z
DTSTART;VALUE=DATE:20240702
DTEND;VALUE=DATE:20240709
SUMMARY:test123 - edited event!!!!
CATEGORIES:other
UID:111
ORGANIZER:aaa
RRULE:FREQ=WEEKLY;UNTIL=20240801;INTERVAL=2;BYDAY=MO
CREATED:20240311T051101Z
LAST-MODIFIED:20240311T051101Z
SEQUENCE:2
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20240707T214014Z
DTSTART;VALUE=DATE:20240701
DTEND;VALUE=DATE:20240708
SUMMARY:test123
CATEGORIES:other
UID:111
ORGANIZER:aaa
RRULE:FREQ=WEEKLY;UNTIL=20240801;INTERVAL=2;BYDAY=MO
EXDATE;VALUE=DATE:20240715
CREATED:20240311T051101Z
LAST-MODIFIED:20240701T063743Z
SEQUENCE:3
END:VEVENT
END:VCALENDAR
"""
calendar = icalendar.Calendar.from_ical(ical_string)
events=recurring_ical_events.of(calendar).at(2024)

for event in events:
    start = event["DTSTART"].dt
    duration = event["DTEND"].dt - event["DTSTART"].dt
    print("start {} duration {}".format(start, duration))

current output:

start 2024-07-02 duration 7 days, 0:00:00
start 2024-07-01 duration 7 days, 0:00:00
start 2024-07-29 duration 7 days, 0:00:00

• EDGE CASE 2 There is another edge case, too: What does the calendar show if you remove this line and import it:

EXDATE;VALUE=DATE:20240715

Can you import this and check?

[zoifar]

Tested 1st case in confluence:

start 2024-07-01 duration 7 days, 0:00:00
start 2024-07-29 duration 7 days, 0:00:00

Also tested 1st case in microsoft and apple:

start 2024-07-02 duration 7 days, 0:00:00
start 2024-07-01 duration 7 days, 0:00:00
start 2024-07-29 duration 7 days, 0:00:00

Tested 2nd case in confluence, microsoft and apple:

start 2024-07-02 duration 7 days, 0:00:00
start 2024-07-01 duration 7 days, 0:00:00
start 2024-07-29 duration 7 days, 0:00:00

[niccokunzmann]

@zoifar Do I see this correctly that confluence and differs from Microsoft and Apple in EDGE CASE 1?

[zoifar]

Just tested 1st case in confluence cloud. Looks like they fixed something in their cloud version of confluence and now it shows the same events as microsoft and apple.

[niccokunzmann]

Yay!

[niccokunzmann]

This is fixed in #149.

[niccokunzmann]

This is released in v2.2.3.