Matches on open time ranges (i.e. no end date) were not properly
handled, as `end` is simply the zero time, which confuses the
`.Before()` and `.After()` logic employed here.
This commit fixes that by adding the appropriate `.IsZero()` checks and
also adds a test case.
The current behavior unfortunately broke compatibility with DAVx5, which
by default queries only events less than 90 days ago (by using an open
time range).
The match helper will now properly return recurring events if any of
their recurrences fall into the queried time range. A test for this was
added as well.
See https://www.rfc-editor.org/errata/eid4164
The original RFC's appendix was missing a part of the calendar data used
in the examples. This will become relevant when adding tests for
retrieving recurring events.
This is not yet complete (see TODOs in code), but basic filtering of a
list of CaledarObjects works.
Includes test data from the RFC, which allows to use the RFCs examples
as test cases.
