"This event only" wrote a `recurrenceOverrides/<id>` pointer on the
master for every occurrence. That pointer fails while the series has
no overrides yet, replaced whatever the occurrence already overrode,
and left the new override without the occurrence's title, place or
reminders. Deleting one occurrence went the same way.
The store now keeps a change to an occurrence on that occurrence, the
way the webmail's `resolveMutationTarget` does:
- a server-expanded occurrence is updated or destroyed through its
synthetic id; a server that refuses synthetic ids gets the same
change as an override on the base event, and is remembered
- an occurrence expanded on the device becomes an override on its base
event that keeps the existing override, pins start and duration,
and is sent as the whole map when the series has none yet
- a new override carries the occurrence's details and sequence
(`withNewOverrideDetails`), so it neither loses them nor ranks below
the series
- "All events" and "This and following" still go to the master
The calendar's scope dialog hands "This event only" to `updateEvent`
and `deleteEvent` with the occurrence's id, and
`buildRecurrenceOverridePatch` is gone.
Linus Rath
f397ee3e1b