Simplify logic

Add a test on what happens currently when apps call `markseen_msgs()` for not downloaded
messages. Such messages are marked as seen, but MDNs aren't sent for them. This is probably correct,
but when a message is downloaded, its state should be downgraded to `InNoticed` and when the user
really sees it, the app should issue `markseen_msgs()` again and that should trigger sending an
MDN. Currently when such a message is downloaded, it remains `InSeen`.

src/message.rs

@@ -2590,6 +2590,60 @@ mod tests {
         Ok(())
     }
 
+    #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+    async fn test_markseen_not_downloaded_msg() -> Result<()> {
+        let mut tcm = TestContextManager::new();
+        let alice = &tcm.alice().await;
+        alice.set_config(Config::DownloadLimit, Some("1")).await?;
+        let bob = &tcm.bob().await;
+        let bob_chat_id = tcm.send_recv_accept(alice, bob, "hi").await.chat_id;
+
+        let file_bytes = include_bytes!("../test-data/image/screenshot.png");
+        let mut msg = Message::new(Viewtype::Image);
+        msg.set_file_from_bytes(bob, "a.jpg", file_bytes, None)
+            .await?;
+        let sent_msg = bob.send_msg(bob_chat_id, &mut msg).await;
+        let msg = alice.recv_msg(&sent_msg).await;
+        assert_eq!(msg.download_state, DownloadState::Available);
+        assert!(!msg.param.get_bool(Param::WantsMdn).unwrap_or_default());
+        assert_eq!(msg.state, MessageState::InFresh);
+        markseen_msgs(alice, vec![msg.id]).await?;
+        let msg = Message::load_from_db(alice, msg.id).await?;
+        assert_eq!(msg.state, MessageState::InSeen);
+        assert!(
+            !alice
+                .sql
+                .exists("SELECT COUNT(*) FROM smtp_mdns", ())
+                .await?
+        );
+
+        alice.set_config(Config::DownloadLimit, None).await?;
+        // Simulate that the message is even marked as `\Seen` on IMAP.
+        let rcvd_msg = receive_imf(alice, sent_msg.payload().as_bytes(), true)
+            .await
+            .unwrap()
+            .unwrap();
+        assert_eq!(rcvd_msg.chat_id, msg.chat_id);
+        let msg = Message::load_from_db(alice, *rcvd_msg.msg_ids.last().unwrap())
+            .await
+            .unwrap();
+        assert_eq!(msg.download_state, DownloadState::Done);
+        assert!(msg.param.get_bool(Param::WantsMdn).unwrap_or_default());
+        assert!(msg.get_showpadlock());
+        assert_eq!(msg.state, MessageState::InNoticed);
+        markseen_msgs(alice, vec![msg.id]).await?;
+        let msg = Message::load_from_db(alice, msg.id).await?;
+        assert_eq!(msg.state, MessageState::InSeen);
+        assert_eq!(
+            alice
+                .sql
+                .count("SELECT COUNT(*) FROM smtp_mdns", ())
+                .await?,
+            1
+        );
+        Ok(())
+    }
+
     #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
     async fn test_get_state() -> Result<()> {
         let alice = TestContext::new_alice().await;

src/receive_imf.rs

@@ -1014,7 +1014,10 @@ async fn add_parts(
             }
         }
 
-        state = if seen
+        state = if replace_msg_id.is_some() {
+            // TODO a comment explaining why we're doing this would be nice
+            MessageState::InNoticed
+        } else if seen
             || fetching_existing_messages
             || is_mdn
             || is_reaction
@@ -1562,7 +1565,7 @@ INSERT INTO msgs
 ON CONFLICT (id) DO UPDATE
 SET rfc724_mid=excluded.rfc724_mid, chat_id=excluded.chat_id,
     from_id=excluded.from_id, to_id=excluded.to_id, timestamp_sent=excluded.timestamp_sent,
-    type=excluded.type, msgrmsg=excluded.msgrmsg,
+    type=excluded.type, state=min(state,excluded.state), msgrmsg=excluded.msgrmsg,
     txt=excluded.txt, txt_normalized=excluded.txt_normalized, subject=excluded.subject,
     txt_raw=excluded.txt_raw, param=excluded.param,
     hidden=excluded.hidden,bytes=excluded.bytes, mime_headers=excluded.mime_headers,
@@ -1613,7 +1616,7 @@ RETURNING id
                     } else {
                         DownloadState::Done
                     },
-                    mime_parser.hop_info
+                    mime_parser.hop_info,
                 ],
                 |row| {
                     let msg_id: MsgId = row.get(0)?;