Use PDU in even more places (#3074)

- No longer rely on *Event returning from NewEventFrom... functions
 
Requires https://github.com/matrix-org/gomatrixserverlib/pull/377

roomserver/internal/helpers/helpers.go

@@ -100,7 +100,7 @@ func IsServerCurrentlyInRoom(ctx context.Context, db storage.Database, serverNam
 func IsInvitePending(
 	ctx context.Context, db storage.Database,
 	roomID, userID string,
-) (bool, string, string, *gomatrixserverlib.Event, error) {
+) (bool, string, string, gomatrixserverlib.PDU, error) {
 	// Look up the room NID for the supplied room ID.
 	info, err := db.RoomInfo(ctx, roomID)
 	if err != nil {

roomserver/internal/input/input_missing.go

@@ -856,7 +856,7 @@ func (t *missingStateReq) lookupEvent(ctx context.Context, roomVersion gomatrixs
 			return events[0].PDU, nil
 		}
 	}
-	var event *gomatrixserverlib.Event
+	var event gomatrixserverlib.PDU
 	found := false
 	for _, serverName := range t.servers {
 		reqctx, cancel := context.WithTimeout(ctx, time.Second*30)

roomserver/internal/perform/perform_upgrade.go

@@ -473,7 +473,7 @@ func (r *Upgrader) sendInitialEvents(ctx context.Context, evTime time.Time, user
 		if i > 0 {
 			builder.PrevEvents = []gomatrixserverlib.EventReference{builtEvents[i-1].EventReference()}
 		}
-		var event *gomatrixserverlib.Event
+		var event gomatrixserverlib.PDU
 		event, err = builder.AddAuthEventsAndBuild(userDomain, &authEvents, evTime, newVersion, r.Cfg.Matrix.KeyID, r.Cfg.Matrix.PrivateKey)
 		if err != nil {
 			return fmt.Errorf("failed to build new %q event: %w", builder.Type, err)

roomserver/internal/query/query_test.go

@@ -26,12 +26,12 @@ import (
 
 // used to implement RoomserverInternalAPIEventDB to test getAuthChain
 type getEventDB struct {
-	eventMap map[string]*gomatrixserverlib.Event
+	eventMap map[string]gomatrixserverlib.PDU
 }
 
 func createEventDB() *getEventDB {
 	return &getEventDB{
-		eventMap: make(map[string]*gomatrixserverlib.Event),
+		eventMap: make(map[string]gomatrixserverlib.PDU),
 	}
 }