Outgoing message got assigned to "Saved messages" instead of 1:1 chat

[link2xt]

I am running recent core, 2.35.0, on two devices.

I have recently set up a contact by scanning a QR (don't remember which direction, likely by me showing a QR) and chatted a bit from android, then opened desktop and see that one of the first message is in the "Saved messages" chat.

There is not much logged, but here is the log of receiving the message on desktop:

2025-12-27T21:09:50.140Z        core/event              INFO    ""      684     "src/imap.rs:1449: Passing message UID 3390 to receive_imf()."
2025-12-27T21:09:50.144Z        core/event              INFO    ""      684     "src/receive_imf.rs:537: Receiving message \"20f877bd-68b9-4074-9d42-c301c38dd730@localhost\", seen=false..."
2025-12-27T21:09:50.145Z        core/event              INFO    ""      684     "src/receive_imf.rs:663: Chat assignment is OneOneChat."
2025-12-27T21:09:50.147Z        core/event              INFO    ""      684     "src/receive_imf.rs:2202: Message has 1 parts and is assigned to chat #Chat#10."
2025-12-27T21:09:50.147Z        core/event              DEBUG   ""      684     "MsgsChanged"   {"chatId":10,"kind":"MsgsChanged","msgId":158048}
2025-12-27T21:09:50.148Z        core/event              DEBUG   ""      684     "ChatlistChanged"       {"kind":"ChatlistChanged"}
2025-12-27T21:09:50.148Z        core/event              DEBUG   ""      684     "ChatlistItemChanged"   {"chatId":10,"kind":"ChatlistItemChanged"}

Message 20f877bd-68b9-4074-9d42-c301c38dd730@localhost is a 1:1 chat message I sent to the chat with the new contact, but it ended up in "saved messages". So the message got OneOneChat assignment according to the log. It could be that I switched primary relay in-between sending the and this is why the message that was incorrectly assigned was fetched before the message that had the contact key.

We should test that if there is an "intended recipient fingerprint" (it should be in every outgoing message) than new contact is created for this fingerprint even when there is no Autocrypt-Gossip and we don't have the key or key-contact yet.

Another outgoing message in the same chat resulted in OneOneChat assignment, but ended up creating unencrypted 1:1 chat (not an ad-hoc group) with this encrypted message inside.