* Ignores any events pushed without a room ID
* Removes needless clones for PDU size checking
* Removes incorrect ACL check in incoming handler
* Fast-path handling already handled outlier events
* Remove redundant same-room checks, replace with useful ones
* Combine event rejection and persistence in a single function
* Additional safety assertions in upgrade task
* Split upgrade task into multiple subroutines for reduced cognitive complexity
* Only mutate current state and forward extremities in tandem
* Improve code documentation to better explain the logic flow

@@ -87,9 +87,7 @@ impl super::Service {
 		let to_persist = if mapped.len() <= 1 {
 			mapped.keys().map(ToOwned::to_owned).collect()

@@ -128,2 +68,2 @@
-
-		if !meta_exists {
+		if !room_exists && !is_interesting_member_event {
+			if is_interesting_member_event {

@@ -155,2 +98,3 @@
-		// 8. if not timeline event: stop
+		// If this is not a timeline event, stop now, as we don't want to de-outlier it.
 		if !is_timeline_event {
+			debug!("Not promoting incoming event as it is not a timeline event");

@@ -171,3 +116,2 @@
 
-		// 9. Fetch any missing prev events doing all checks listed here starting at 1.
-		//    These are timeline events
+		// Fetch any missing prev events doing all checks listed here starting at 1.

@@ -33,2 +47,3 @@
+		if !Self::pdu_format_check_1(&value) {
 			warn!(
-				"dropping incoming PDU {event_id} in room {room_id} from {origin} because it \
+				"Dropping incoming PDU {event_id} in room {room_id} from {origin} because it \

@@ -382,2 +216,3 @@
-		if soft_fail {
+
+		if should_soft_fail {
 			self.services

@@ -297,11 +297,7 @@ async fn handle_room(
 	// failure (e.g., cycles). This is best-effort; proper ordering is the sender's
 	// responsibility.
 	let sorted_event_ids = if pdu_map.len() >= 2 {

@@ -385,3 +173,2 @@
-				.mark_event_soft_failed(incoming_pdu.event_id());
 
-			info!(
+		if should_soft_fail {