Bug 434599

Created attachment 136832 [details]
An export of the invalid iCal file, whose EXDATE seems invalid

SUMMARY

When deleting a single occurrence of a recurring event with a timezone, thus creating an exception to a recurrence, Korganizer assigns an EXDATE using VALUE instead of TZID, apparently violating the CalDAV spec.

Some CalDAV servers reject the change. Unfortunately, the change is cached locally, so we get an inconsistent view of the calendar---other clients don't show the change.


STEPS TO REPRODUCE
1. Create a recurring event with a specific timezone, such as American/Vancouver.
2. Delete 1 occurrence of the event, creating an exception.
3. Export the event to an iCal file.

OBSERVED RESULT
On the server:
```
WARNING: Bad PUT request on '/CA4413E8-13F2-465C-B1BA-EF2420F9DDFA/1616109800.R60.ics': Failed to store item '1616109800.R60.ics' in collection '/CA4413E8-13F2-465C-B1BA-EF2420F9DDFA': can't compare offset-naive and offset-aware datetimes
```

In the iCal file, the exception will appear as:
```
EXDATE;VALUE=DATE:20210317
DTSTART;TZID=America/Vancouver:20210315T190000
DTEND;TZID=America/Vancouver:20210315T200000
```

EXPECTED RESULT

In the iCal file, the exception should appear as:
```
EXDATE;TZID=America/Vancouver:20210317T190000
DTSTART;TZID=America/Vancouver:20210315T190000
DTEND;TZID=America/Vancouver:20210315T200000
```

SOFTWARE/OS VERSIONS:
Linux 5.10.15-1-MANJARO 64bit
KDE Plasma Version: 5.20.5
KDE Frameworks Version: 5.78.0
Qt Version: 5.15.2

ADDITIONAL INFORMATION

The spec suggests that if the RSTART is a TZID, the EXDATE should be too:
https://tools.ietf.org/html/rfc5545#section-3.2.19