feat: Sync Config::DeleteServerAfter across devices

[iequidoo]

No description provided.

[iequidoo]

Btw too small DeleteServerAfter values can break the synchronisation itself because other devices have little chance to see sync messages. Maybe we should add a lower limit on synchronised values?

[iequidoo]

Btw too small DeleteServerAfter values can break the synchronisation itself because other devices have little chance to see sync messages. Maybe we should add a lower limit on synchronised values?

Maybe this is not critical because DeleteServerAfter can be increased on all devices reliably because the setting is applied before the decision of sync message removal is made. At least it looks working, added a Python test for this.

[Hocuri]

Was there any discussion about this?

The downside of syncing DeleteServerAfter is of course that the following use case doesn't work:

• Have a PC, which is running at least once a week, and a phone, which is running constantly (more than once a day)
• On the phone, set DeleteServerAfter to 1 week, so that the PC has a chance to download the messages. On the PC, set DeleteServerAfter to 1 day, so that messages are quickly deleted.

OTOH, this is a very advanced use case, and most users won't understand how to configure this.

[iequidoo]

Was there any discussion about this?

I've already forgotten who suggested (to think about?) this, but probably @r10s as i added them to reviewers :)

The downside of syncing DeleteServerAfter is of course that the following use case doesn't work:

• Have a PC, which is running at least once a week, and a phone, which is running constantly (more than once a day)

• On the phone, set DeleteServerAfter to 1 week, so that the PC has a chance to download the messages. On the PC, set DeleteServerAfter to 1 day, so that messages are quickly deleted.

This is still possible to configure as for any other synchronised setting: turn BccSelf off, change settings so that no sync messages are sent, turn on BccSelf back. Rather there's a question which scenario is more often -- having DeleteServerAfter different or the same on different devices.