Review comments

Author: neilalexander

authstate.go

@@ -165,10 +165,7 @@ func checkAllowedByAuthEvents(
 	event PDU, eventsByID map[string]PDU,
 	missingAuth EventProvider, userIDForSender spec.UserIDForSender,
 ) error {
-	authEvents, err := NewAuthEvents(nil)
-	if err != nil {
-		return err
-	}
+	authEvents, _ := NewAuthEvents(nil)
 
 	for _, ae := range event.AuthEventIDs() {
 	retryEvent:
@@ -338,10 +335,7 @@ func CheckSendJoinResponse(
 	}
 
 	eventsByID := map[string]PDU{}
-	authEventProvider, err := NewAuthEvents(nil)
-	if err != nil {
-		return nil, err
-	}
+	authEventProvider, _ := NewAuthEvents(nil)
 
 	// Since checkAllowedByAuthEvents needs to be able to look up any of the
 	// auth events by ID only, we will build a map which contains references

stateresolutionv2.go

@@ -444,10 +444,12 @@ func (r *stateResolverV2) getFirstPowerLevelMainlineEvent(event PDU) (
 func (r *stateResolverV2) authAndApplyEvents(events ...PDU) {
 	addFromAuthEventsIfNotRejected := func(event PDU, eventType, stateKey string) {
 		for _, authEventID := range event.AuthEventIDs() {
-			if _, ok := r.isRejectedCache[authEventID]; !ok {
-				r.isRejectedCache[authEventID] = r.isRejectedFn(authEventID)
+			rejected, ok := r.isRejectedCache[authEventID]
+			if !ok {
+				rejected = r.isRejectedFn(authEventID)
+				r.isRejectedCache[authEventID] = rejected
 			}
-			if rejected := r.isRejectedCache[authEventID]; rejected {
+			if rejected {
 				continue
 			}
 			authEv, ok := r.authEventMap[authEventID]