fix: Emit MsgsChanged, not IncomingMsg, for messages only having special parts (#8157)

And example of such messages is location-only messages.

src/location.rs

@@ -861,7 +861,7 @@ mod tests {
     use crate::config::Config;
     use crate::message::MessageState;
     use crate::receive_imf::receive_imf;
-    use crate::test_utils::{TestContext, TestContextManager};
+    use crate::test_utils::{TestContext, TestContextManager, event_tracker::GetMatchingArgs};
     use crate::tools::SystemTime;
 
     #[test]
@@ -1107,7 +1107,18 @@ Content-Disposition: attachment; filename="location.kml"
         SystemTime::shift(Duration::from_secs(10));
         delete_expired(alice, time()).await?;
         maybe_send_locations(alice).await?;
+        bob.evtracker.clear_events();
         bob.recv_msg_opt(&alice.pop_sent_msg().await).await;
+        bob.evtracker
+            .get_matching_ex(
+                bob,
+                GetMatchingArgs {
+                    expected: |e| matches!(e, EventType::MsgsChanged { .. }),
+                    unexpected: |e| matches!(e, EventType::IncomingMsg { .. }),
+                },
+            )
+            .await
+            .unwrap();
         assert_eq!(get_range(alice, None, None, 0, 0).await?.len(), 1);
         assert_eq!(get_range(bob, None, None, 0, 0).await?.len(), 1);
 

src/receive_imf.rs

@@ -1075,8 +1075,11 @@ UPDATE msgs SET state=? WHERE
         let is_bot = context.get_config_bool(Config::Bot).await?;
         let is_pre_message = matches!(mime_parser.pre_message, PreMessageMode::Pre { .. });
         let skip_bot_notify = is_bot && is_pre_message;
-        let important =
+        let important = mime_parser.incoming
-            mime_parser.incoming && fresh && !is_old_contact_request && !skip_bot_notify;
+            && !mime_parser.parts.is_empty()
+            && fresh
+            && !is_old_contact_request
+            && !skip_bot_notify;
 
         for msg_id in &received_msg.msg_ids {
             chat_id.emit_msg_event(context, *msg_id, important);

src/test_utils.rs

@@ -1433,6 +1433,16 @@ pub fn fiona_keypair() -> SignedSecretKey {
 #[derive(Debug)]
 pub struct EventTracker(EventEmitter);
 
+pub mod event_tracker {
+    use super::EventType;
+
+    /// See [`super::EventTracker::get_matching_ex`].
+    pub struct GetMatchingArgs<E: Fn(&EventType) -> bool, U: Fn(&EventType) -> bool> {
+        pub expected: E,
+        pub unexpected: U,
+    }
+}
+
 impl Deref for EventTracker {
     type Target = EventEmitter;
 
@@ -1488,6 +1498,27 @@ impl EventTracker {
         }
     }
 
+    /// Consumes all emitted events returning the first matching one if any. Panics on unexpected
+    /// events.
+    pub async fn get_matching_ex<E: Fn(&EventType) -> bool, U: Fn(&EventType) -> bool>(
+        &self,
+        ctx: &Context,
+        args: event_tracker::GetMatchingArgs<E, U>,
+    ) -> Option<EventType> {
+        ctx.emit_event(EventType::Test);
+        let mut found_event = None;
+        loop {
+            let event = self.recv().await.unwrap();
+            assert!(!(args.unexpected)(&event.typ));
+            if let EventType::Test = event.typ {
+                return found_event;
+            }
+            if (args.expected)(&event.typ) {
+                found_event.get_or_insert(event.typ);
+            }
+        }
+    }
+
     /// Consumes events looking for an [`EventType::Info`] with substring matching.
     pub async fn get_info_contains(&self, s: &str) -> EventType {
         self.get_matching(|evt| match evt {