- Alice has two devices, the second is offline.
- Alice creates a verified group and sends a QR invitation to Bob.
- Bob joins the group and sends a message there. Alice sees it.
- Alice's second devices goes online, but doesn't see Bob in the group.
This allows to distinguish exceptions,
such as database errors, from invalid user input.
For example, if the From: field of the message
does not look like an email address, the mail
should be ignored. But if there is a database
failure while writing a new contact for the address,
this error should be bubbled up.
It's a w/a for "Space added before long group names after MIME serialization/deserialization"
issue. DC itself never creates group names with leading/trailing whitespace, so it can be safely
removed. On the sender side there's no trim() because group names anyway go through
improve_single_line_input(). And I believe we should send the exact name we have in our db. Also
there's no check for leading/trailing whitespace because there may be existing user databases with
group names having such whitespaces.
That's a bug which @Simon-Laux and probably also @hpk42 had, where one malformed incoming (Spam-) mail blocked the receiving of all emails coming after it.
The problem was that from_field_to_contact_id() returned ContactId::UNDEFINED, and then lookup_by_contact() returned Err.
