fix(1163): Resolve algorithm misinterpretations

src/core/matrix/state_res/mod.rs

@@ -101,40 +101,40 @@ where
 	debug!(version = ?stateres_version, "State resolution starting");
 
 	// Split non-conflicting and conflicting state
-	let (clean, conflicting) = separate(state_sets.into_iter());
+	let (unconflicted, conflicting) = separate(state_sets.into_iter());
 
-	debug!(count = clean.len(), "non-conflicting events");
+	debug!(count = unconflicted.len(), "non-conflicting events");
-	trace!(map = ?clean, "non-conflicting events");
+	trace!(map = ?unconflicted, "non-conflicting events");
 
 	if conflicting.is_empty() {
 		debug!("no conflicting state found");
-		return Ok(clean);
+		return Ok(unconflicted);
 	}
 
 	debug!(count = conflicting.len(), "conflicting events");
 	trace!(map = ?conflicting, "conflicting events");
-	let conflicted_state_subgraph: HashSet<_> = match stateres_version {
+	let (conflicted_state_subgraph, initial_state) =
-		| StateResolutionVersion::V2_1 =>
+		if stateres_version == StateResolutionVersion::V2_1 {
-			calculate_conflicted_subgraph(&conflicting, event_fetch)
+			let csg = calculate_conflicted_subgraph(&conflicting, event_fetch)
 				.await
 				.ok_or_else(|| {
 					Error::InvalidPdu("Failed to calculate conflicted subgraph".to_owned())
-				})?,
+				})?;
-		| _ => HashSet::new(),
+			debug!(count = csg.len(), "conflicted subgraph");
+			trace!(set = ?csg, "conflicted subgraph");
+			(csg, HashMap::new())
+		} else {
+			(HashSet::new(), unconflicted.clone())
 		};
-	debug!(count = conflicted_state_subgraph.len(), "conflicted subgraph");
-	trace!(set = ?conflicted_state_subgraph, "conflicted subgraph");
-
-	let conflicting_values = conflicting.into_values().flatten().stream();
 
 	// `all_conflicted` contains unique items
 	// synapse says `full_set = {eid for eid in full_conflicted_set if eid in
 	// event_map}`
 	// Hydra: Also consider the conflicted state subgraph
 	let all_conflicted: HashSet<_> = get_auth_chain_diff(auth_chain_sets)
-		.chain(conflicting_values)
+		.chain(conflicting.into_values().flatten().stream())
-		.chain(conflicted_state_subgraph.into_iter().stream())
 		.broad_filter_map(async |id| event_exists(id.clone()).await.then_some(id))
+		.chain(conflicted_state_subgraph.into_iter().stream())
 		.collect()
 		.await;
 
@@ -171,7 +171,7 @@ where
 		&room_version,
 		&stateres_version,
 		sorted_control_levels.iter().stream().map(AsRef::as_ref),
-		clean.clone(),
+		initial_state,
 		&event_fetch,
 	)
 	.await?;
@@ -201,7 +201,7 @@ where
 	let power_levels_ty_sk = (StateEventType::RoomPowerLevels, StateKey::new());
 	let power_event = resolved_control.get(&power_levels_ty_sk);
 
-	debug!(event_id = ?power_event, "power event");
+	trace!(event_id = ?power_event, "power event");
 
 	let sorted_left_events =
 		mainline_sort(&events_to_resolve, power_event.cloned(), &event_fetch).await?;
@@ -212,13 +212,13 @@ where
 		&room_version,
 		&stateres_version,
 		sorted_left_events.iter().stream().map(AsRef::as_ref),
-		resolved_control.clone(), // The control events are added to the final resolved state
+		resolved_control, // The control events are added to the final resolved state
 		&event_fetch,
 	)
 	.await?;
 
 	// Ensure unconflicting state is in the final state
-	resolved_state.extend(clean);
+	resolved_state.extend(unconflicted);
 
 	debug!("state resolution finished");
 	trace!( map = ?resolved_state, "final resolved state" );