Headers like From and Autocrypt are now added late,
right before sending the message over SMTP.
This way we advertise the latest list of transports
and use the correct From address in the encrypted part
even for messages queued while being offline.
BCC-self recipients are also added late.
For unencrypted messages we only want to send a copy
to the sending address, but we don't know the sending address
when queueing the message.
Adding bcc-self recipients when dequeuing the message
also makes it possible to send copies to updated list of relays.
With I/O stopped, `background_fetch()` connected only to the transport of `configured_addr`
and we now instead fan out to all transports in a controlled loop.
If a first transport finished fetching new messages
cancel all other attempts and return.
This is meant to address the problem that amzd described
where a profile with one functioning and one hanging transport,
shows the first notification, then hangs 15 seconds waiting for the hanging transport.
meanwhile a second NSE arrives and dies, and the second message is not notified
or only generically.
Also drop the quota check from this background fetch path:
its result is in-memory only, discarded when the iOS notification service exits,
and the regular scheduler fetching refreshes it every 60s anyway.
Moreover, quota errors/running full is pretty rare
since relays generally automatically stay under quota these days.
It's another round trip for each transport of each profile and simply not necessary.
Also adds previously missing online tests.
Removing a relay now takes effect immediately:
- the profile stops fetching and advertising it,
- secondary devices immediately apply the removal through the transport sync,
Upgrading removes unpublished relays and triggers keyupdates.
BREAKING CHANGE: set_transport_unpublished() is removed: UIs call delete_transport() when the user removes a relay.
BREAKING CHANGE: list_transports_ex() and the TransportListEntry type are removed: use list_transports().
BREAKING CHANGE: delete_transport() no longer refuses to remove the primary transport: it refuses only to remove the last one and re-elects the sending transport as needed.
BREAKING CHANGE: TransportsModified is now also emitted on the device modifying the transports, not only on devices applying the synced change.
Deprecated: DC_STR_PHASING_OUT
Devices no longer implicitely use the From address of sync messages
to determine their primary transport. Receivers have no concept of it and own devices
may disagree on which relay is reachable because of VPN or different networks:
1. Make setting a primary transport (`configured_addr`) a per-device non-synced operation.
2. Transport rows (add/remove/unpublish) keep syncing like before.
3. A device reelects a primary if a sync message unpublished/removed the current primary
if there is a better candidate.
4. `TransportsModified` event is emitted at most once on an incoming transport sync message.
Users will notice the change in that changing primary transport in settings/advanced/relays
will not synchronize to other devices anymore.
Fix https://github.com/chatmail/core/issues/7835.
The problem was most probably:
- `ac1_clone` receives the sync message, sends `TRANSPORTS_MODIFIED`
event, and launches a task that will restart IO
- After IO was stopped, but before it is started again,
`ac1_clone.add_transport_from_qr(qr)` is called
- this check fails:
```rust
ensure!(
!self.scheduler.is_running().await,
"cannot configure, already running"
);
```
This fixes the bug when a new transport doesn't become primary on the 2nd device because INBOX from
the new transport isn't fully fetched. Now the `Transports` sync message is received from the old
transport, but as it has updated "From", it updates the primary transport correspondingly. NB: I/O
for the new primary transport isn't immediately started however, this needs a separate fix.
Fix get_secondary_addrs() which was using
`secondary_addrs` config that is not updated anymore.
Instead of using `secondary_addrs` config,
use the `transports` table which contains all the addresses.
