Hopefully fix panics for good in SQLite this time

internal/sqlutil/sql.go

@@ -40,11 +40,6 @@ type Transaction interface {
 // You MUST check the error returned from this function to be sure that the transaction
 // was applied correctly. For example, 'database is locked' errors in sqlite will happen here.
 func EndTransaction(txn Transaction, succeeded *bool) error {
-	if txn == nil {
-		// Sometimes in SQLite mode we have nil transactions. If that's the case
-		// then we are working outside of a transaction and should do nothing here.
-		return nil
-	}
 	if *succeeded {
 		return txn.Commit()
 	} else {

roomserver/storage/shared/room_updater.go

@@ -61,6 +61,22 @@ func NewRoomUpdater(ctx context.Context, d *Database, txn *sql.Tx, roomInfo *typ
 	}, nil
 }
 
+// Implements sqlutil.Transaction
+func (u *RoomUpdater) Commit() error {
+	if u.txn == nil { // SQLite mode probably
+		return nil
+	}
+	return u.txn.Commit()
+}
+
+// Implements sqlutil.Transaction
+func (u *RoomUpdater) Rollback() error {
+	if u.txn == nil { // SQLite mode probably
+		return nil
+	}
+	return u.txn.Commit()
+}
+
 // RoomVersion implements types.RoomRecentEventsUpdater
 func (u *RoomUpdater) RoomVersion() (version gomatrixserverlib.RoomVersion) {
 	return u.roomInfo.RoomVersion

roomserver/storage/shared/storage.go

@@ -649,7 +649,7 @@ func (d *Database) storeEvent(
 			if err != nil {
 				return 0, 0, types.StateAtEvent{}, nil, "", fmt.Errorf("GetRoomUpdater: %w", err)
 			}
-			defer sqlutil.EndTransactionWithCheck(updater.txn, &succeeded, &err)
+			defer sqlutil.EndTransactionWithCheck(updater, &succeeded, &err)
 		}
 		if err = updater.StorePreviousEvents(eventNID, prevEvents); err != nil {
 			return 0, 0, types.StateAtEvent{}, nil, "", fmt.Errorf("updater.StorePreviousEvents: %w", err)