TTDPatch

cb11 (and possibly other callbacks) don't appear to be run when the train leaves the depot, or when a vehicle is bought or sold. The callback seems to be run only when the train arrives at the depot, or when dragging-and-dropping vehicles. This means if you buy or sell a vehicle in the depot but do not drag-or-drop vehicles in or out of the train, the train vehicles can end up the wrong length.