joining verified group via QR not working properly if contact is not already verified

[adbenitez]

testing around I discovered this bug, info message shown as normal message (even if I got added correctly)
steps to reproduce:

1. create new account B
2. create new verified group in account B
3. scan the QR with your other accout A, that should have not B verified already, that is: the group-join-QR will be the first time you also get verified with that contact

[iequidoo]

Can be reproduced by the Python tests with this patch:

--- a/python/tests/test_0_complex_or_slow.py                                                                                                                                                                         
+++ b/python/tests/test_0_complex_or_slow.py                                                                                                                                                                         
@@ -136,6 +136,7 @@ def test_qr_verified_group_and_chatting(acfactory, lp):                                                                                                                                          
     lp.sec("ac2: read member added message")                                                                                                                                                                        
     msg = ac2._evtracker.wait_next_incoming_message()                                                                                                                                                               
     assert msg.is_encrypted()                                                                                                                                                                                       
+    assert msg.is_system_message()                                                                                                                                                                                  
     assert "added" in msg.text.lower()                                                                                                                                                                              
                                                                                                                                                                                                                     
     lp.sec("ac1: send message")

[iequidoo]

50.90 [events-ac2] INFO src/mimeparser.rs:300: decrypted message mime-body:
Content-Type: text/plain; charset=utf-8; format=flowed; delsp=no;                                                                                                                                                    
        protected-headers="v1";                                                                                                                                                                                      
Subject: hello
Chat-Verified: 1
Chat-Group-ID: eIIBkMWNYqg
Chat-Group-Name: =?utf-8?q?hello?=
Chat-Group-Member-Added: 2cyz8@ci.testrun.org
Secure-Join: vg-member-added
Secure-Join-Fingerprint: CCCB5AA9F6E1141C943165F1DB18B18CBCF70487
From: <ecj2q@ci.testrun.org>

I added member 2cyz8@ci.testrun.org.

50.90 [events-ac2] WARNING src/mimeparser.rs:813: Ignoring nested protected headers
50.90 [events-ac2] INFO src/receive_imf.rs:142: Received message has Message-Id: Gr.eIIBkMWNYqg.GmQhYmknOMi@ci.testrun.org
50.90 [events-ac2] INFO src/securejoin.rs:290: >>>>>>>>>>>>>>>>>>>>>>>>> secure-join message 'vg-member-added' received
50.90 [events-ac2] INFO src/securejoin/bobstate.rs:334: Bob Step 7 - handling vc-contact-confirm/vg-member-added message
50.90 [events-ac2] DC_EVENT_CONTACTS_CHANGED data1=0 data2=0
50.90 [events-ac2] INFO src/ephemeral.rs:567: Ephemeral loop waiting for deletion in 24h 0m 0s or interrupt
50.90 [events-ac2] INFO src/mimefactory.rs:1049: sending secure-join message 'vg-member-added-received' >>>>>>>>>>>>>>>>>>>>>>>>>
50.90 [events-ac2] INFO src/e2ee.rs:65: peerstate for "ecj2q@ci.testrun.org" is mutual
50.90 [events-ac2] DC_EVENT_MSGS_CHANGED data1=12 data2=17
50.91 [events-ac2] INFO src/scheduler.rs:714: smtp fake idle - interrupted
50.91 [events-ac2] INFO src/smtp.rs:656: Selected rows from SMTP queue: [3].
50.91 [events-ac2] INFO src/smtp.rs:551: Try number 1 to send message Msg#17 (entry 3) over SMTP
50.91 [events-ac2] DC_EVENT_CONNECTIVITY_CHANGED data1=0 data2=0
50.91 [events-ac2] DC_EVENT_MSGS_CHANGED data1=13 data2=18
50.91 [events-ac2] DC_EVENT_CHAT_MODIFIED data1=13 data2=0
50.91 [events-ac2] INFO src/chat.rs:1078: Set gossiped_timestamp for chat Chat#13 to 0.
50.91 [events-ac2] DC_EVENT_MSGS_CHANGED data1=13 data2=19
50.91 [events-ac2] DC_EVENT_CHAT_MODIFIED data1=13 data2=0
50.91 [events-ac2] WARNING src/receive_imf.rs:1571: Verification problem: The message was sent with non-verified encryption.
50.91 [events-ac2] INFO src/receive_imf.rs:1848: Recreating chat Chat#13 with members {ContactId(10), ContactId(1)}.
50.91 [events-ac2] DC_EVENT_CHAT_MODIFIED data1=13 data2=0
50.91 [events-ac2] WARNING src/receive_imf.rs:1041: Verification problem: The message was sent with non-verified encryption.
50.91 [events-ac2] INFO src/receive_imf.rs:1284: Message has 1 parts and is assigned to chat #Chat#13.
50.91 [events-ac2] INFO src/contact.rs:1632: Recently seen loop waiting for 0h 9m 51s or interrupt
50.91 [events-ac2] DC_EVENT_INCOMING_MSG data1=13 data2=20
50.91 [events-ac2] INFO src/imap.rs:1565: Successfully received 1 UIDs.
50.91 [events-ac2] INFO src/imap.rs:886: 1 mails read from "INBOX".is_info: cmd=Unknown, text='Member Me (2cyz8@ci.testrun.org) added by ecj2q@ci.testrun.org.'

50.91 [events-ac2] DC_EVENT_INCOMING_MSG_BUNCH data1=0 data2=0
-------------------------------------------------------------------------------------------- Captured stdout teardown --------------------------------------------------------------------------------------------

So, the problem is related to these messages (there are two of them):

Verification problem: The message was sent with non-verified encryption.

mime_parser.repl_msg_by_error() is called then which resets self.is_system_message from MemberAddedToGroup to Unknown. Then it is saved to the db as Param::Cmd. And then Message::is_info() called on such a message returns false:

    pub fn is_info(&self) -> bool {
        let cmd = self.param.get_cmd();
        self.from_id == ContactId::INFO                                                                                                                                                                              
            || self.to_id == ContactId::INFO
            || cmd != SystemMessage::Unknown && cmd != SystemMessage::AutocryptSetupMessage
    }

As i can see, the bug is introduced by 9cd000c "feat: Verified 1:1 chats (#4315)". Right now i have no idea how to rewrite the code properly, i'm not very familiar with it. @Hocuri

EDIT: Found a simple way to fix this. The reason is that mime_parser.decryption_info.peerstate is not updated when handling a Securejoin handshake, it's updated only in the db.