Performance issue/lag drawing in "Auto" mode on a tilemap layer

We don't know the exact problem but we have a file to reproduce this issue in the ticket (the file was sent privately via support email address, please keep it private).

Ticket: https://igarastudio.zendesk.com/agent/tickets/2539

EDIT: The problem was that was an out-of-bounds tile reference outside the tileset range (and the index was too big, like `0xffffff` or something like that).