Read and write time zone ID when updating CalDAV availability

[ChristophWurst]

Tiny bug/limitation of #27466

Now the timezone id is read from the previous value but also encoded in the newly saved icalendar value. If no time zone was set before it will still fall back to the auto detected one.

How to test

• Open /settings/user/groupware
• Set the timezone to something other than the auto-detected value
• Save the availability
• Reload the page

On master: you see the auto detected time zone again
On this branch: time zone is the one you previously stored

Without this fix reloading the page and saving the availability will shift your times by the drift of the time zone.

I tested this against an availability rule created by Apple Calendar. The only diff to their format is that we don't generate the DST vs standard time recurrence rules within the timezone component but I guess we would need some data for this that we currently don't have. done with the help of https://www.npmjs.com/package/icalzone

[tcitworld]

The data from https://github.com/touch4it/ical-timezones/tree/master/lib/zones seems to never have been updated since the start of the project, so we'll probably encounter issues soon enough.

[ChristophWurst]

The data from https://github.com/touch4it/ical-timezones/tree/master/lib/zones seems to never have been updated since the start of the project, so we'll probably encounter issues soon enough.

Fair point, but do we have alternatives?

[ChristophWurst]

The data from https://github.com/touch4it/ical-timezones/tree/master/lib/zones seems to never have been updated since the start of the project, so we'll probably encounter issues soon enough.

I ran their generator. I don't see any changes except formatting differences with quoted object key.

[tcitworld]

I ran their generator. I don't see any changes except formatting differences with quoted object key.

That's because it doesn't update the .ics files, only the js files. The VTIMEZONE data was provided by https://github.com/benfortuna/tzurl (according to this).

I've used https://github.com/libical/vzic/ (which seems active) to generate the VTIMEZONE data from latest IANA data but I've yet to use it with touch4it/ical-timezones.

[ChristophWurst]

I've used https://github.com/libical/vzic/ (which seems active) to generate the VTIMEZONE data from latest IANA data but I've yet to use it with touch4it/ical-timezones.

Is there anything I could help with?

[skjnldsv]

Rebasing? :)

[tcitworld]

Is there anything I could help with?

Nah, that's non blocking for this PR anyway.

[skjnldsv]

Changes not staged for commit:
  (use "git add <file>..." to update what will be committed)
  (use "git restore <file>..." to discard changes in working directory)
	modified:   apps/dav/js/settings-personal-availability.js
	modified:   apps/dav/js/settings-personal-availability.js.map

[skjnldsv]

Minor request, otherwise looks good!

[GretaD]

tested and it works