configured_imap_certificate_checks=0 means
accept invalid certificates unless provider database
says otherwise or SOCKS5 is enabled.
It should not be saved into the database anymore.
This bug was introduced in
<https://github.com/deltachat/deltachat-core-rust/pull/5854>
(commit 6b4532a08e)
and affects released core 1.142.4, 1.142.5 and 1.142.6.
Fix reverts faulty fix from
<https://github.com/deltachat/deltachat-core-rust/pull/5886>
(commit a268946f8d)
which changed the way configured_imap_certificate_checks=0
is interpreted and introduced problems
for existing setups with configured_imap_certificate_checks=0:
<https://github.com/deltachat/deltachat-core-rust/issues/5889>.
Existing test from previous fix is not reverted
and still applies.
Regression test is added to check that
configured_imap_certificate_checks
is not "0" for new accounts.
If user has not set any settings manually
and provider is not configured,
default to strict TLS checks.
Bug was introduced in
<https://github.com/deltachat/deltachat-core-rust/pull/5854>
(commit 6b4532a08e)
and affects released core 1.142.4 and 1.142.5.
The problem only affects accounts configured
using these core versions with provider
not in the provider database or when using advanced settings.
`Context::send_sync_msg()` mustn't be called from multiple tasks in parallel to avoid sending the
same sync items twice because sync items are removed from the db only after successful
sending. Let's guarantee this by calling `send_sync_msg()` only from the SMTP loop. Before
`send_sync_msg()` could be called in parallel from the SMTP loop and another task doing
e.g. `chat::sync()` which led to `test_multidevice_sync_chat` being flaky because of events
triggered by duplicated sync messages.
This way it's clearer which key is which and also adding the key fingerprint to the file name avoids
overwriting another previously exported key. I think this is better than adding an incremental
number as we do for backups, there's no need to export a key several times to different files.