Excluding Outlook items by status does not work for individual recurring series occurrences

[phw198]

I marked future recurring events as 'tentative', then performed a sync. Some of the events are not removed. Some events, whose whole recurring sequence I marked 'tentative' long ago, work correctly.

I currently have 'tentative' marked as to be excluded. The rate range for syncing is -1 to 21. I increased it to -60 to 60 to see if that helped.
I upgraded to 2.10.2-alpha to see if that helped.
I checked my settings to confirm they are still set as I expected.
I tried deleted all OGCS events in Google to 'reset' (I used Outlook -> Google sync only, with merge events and no confirmation on deletions).

Attached is today's log.
OGcalsync.log

An example event that is recurring and 'tentative', but appears in my Google calendar is here, starting at line 130 in the log:

2023-12-18 08:49:16,558 DEBUG  20 OutlookGoogleCalendarSync.GoogleOgcs.Calendar [660] -  Processing >> 04/12/2023 15:30 (R) => "O2A UAT-Dec - Defect Triage (UK)"
2023-12-18 08:49:16,561 DEBUG  20 OutlookGoogleCalendarSync.Recurrence [32] -  Creating Google iCalendar definition for recurring event.
2023-12-18 08:49:16,746 DEBUG  20 OutlookGoogleCalendarSync.Recurrence [48] -  RRULE:FREQ=WEEKLY;BYDAY=MO,TU,WE,TH;UNTIL=20231222T160000Z
2023-12-18 08:49:16,777 DEBUG  20 OutlookGoogleCalendarSync.Recurrence [665] -  04/12/2023 15:30 (R) => "O2A UAT-Dec - Defect Triage (UK)"
2023-12-18 08:49:16,778 DEBUG  20 OutlookGoogleCalendarSync.Recurrence [666] -  This is a recurring appointment with 3 exceptions that will now be iteratively compared.
2023-12-18 08:49:16,873 DEBUG  20 OutlookGoogleCalendarSync.Recurrence [442] -  Finding Google instance for Outlook exception:-
2023-12-18 08:49:16,875 DEBUG  20 OutlookGoogleCalendarSync.Recurrence [443] -    Original date: 20/12/2023
2023-12-18 08:49:16,891 DEBUG  20 OutlookGoogleCalendarSync.Recurrence [447] -    Current  date: 20/12/2023
2023-12-18 08:49:16,898 DEBUG  20 OutlookGoogleCalendarSync.Recurrence [471] -  Google exception event is not cached. Retrieving all recurring instances...
2023-12-18 08:49:16,899 DEBUG  20 OutlookGoogleCalendarSync.GoogleOgcs.Calendar [165] -  Retrieving all recurring event instances from Google for ujg6i6fg6gvfelq08p7eqrmr2s
2023-12-18 08:49:17,047 DEBUG  20 OutlookGoogleCalendarSync.GoogleOgcs.Calendar [174] -  Page 1 received.
2023-12-18 08:49:17,051 DEBUG  20 OutlookGoogleCalendarSync.Recurrence [695] -  Matching Google Event recurrence found.
2023-12-18 08:49:17,068 DEBUG  20 OutlookGoogleCalendarSync.GoogleOgcs.Calendar [660] -  Processing >> 20/12/2023 15:30 (R) => "O2A UAT-Dec - Defect Triage (UK)"
2023-12-18 08:49:17,098 DEBUG  20 OutlookGoogleCalendarSync.Recurrence [731] -  Doing a dummy update in order to update the last modified date of Google recurring series exception.

Edit:
As a test, I marked a whole sequence of recurring events as tentative. A sync removed these as expected.
I then marked two events in the sequence as accepted (today and tomorrow) and performed a new sync. These were not synced to the Google calendar.

Edit2:
I saw in another issue to try exporting the CSV from OGCS. The 'outlook_appointments.csv' does not contain the two accepted events from the series I set to tentative.
If I search outlook by meetingstatus:accepted they don't appear there either. Possibly an Outlook issue?

Edit3:
Tried declining the original invite (for the whole series), which synced correctly.
Then I accepted the original invite, which synced correctly.
Then I declined one occurrence, which synced correctly.
Then I set one occurrence to tentative. This change did not sync.
Using the original invite to set the whole series to tentative, then accepting one occurrence does not work - the whole series is deleted on sync.

Originally posted by @euinor in #1743 (comment)

[euinor]

FYI, I don't have any current examples of recurring appointments that are causing issues - so possibly the issue is fixed. Or least I can't support that is it still a problem :)

[phw198]

Hi @euinor - I'll leave this open as I haven't had time to test this, but....I don't think exclusions on individual recurring occurrences is even going to work/be possible. The problem is that in both Outlook and Google, once an occurrence is deleted, it's not possible to restore/resync it. The only way would be to remove the entire series and recreate it, which is far from ideal.

Note, an equivalent issue already exists in OCGS: if you decline an Outlook invite for an occurrence of a series and suggest a new time (Google's occurrence gets deleted), and then the organiser accepts the new time and which you then also accept. In this situation OGCS displays a warning the Google series needs manually deleting in order the series can be resynced.

[euinor]

I did attempt to fix the issue by deleting the whole event series from my Google calendar and syncing again to fix it but it didn't help.

Personally I don't mind a drastic measure like deleting the whole sequence in order to fix edge cases. But I only use one way sync, so it is simple for me to do.

[phw198]

Sorry, to be clear, when excluding items based on status this will only affect stand-alone items or entire series - not series occurrences. I'll try and make that clearer in the application.

I don't currently plan on changing that behaviour, but could consider it as a later enhancement.

[phw198]