TTDPatch

TTDPatch Version: 2.5 and 2.6
Patch Feature: newgrf

(For trains,) depending on the veh-ID, the behaviour of specifying cargomask bits is different:

1) for veh-IDs of original engines, if the cargomask property isn´t used at all or has been set to zero, a vehicle will be refittable to "foreign", unspecified, cargoes too.

2) for veh-IDs of original wagons, if the cargomask property isn´t used at all or has been set to zero, a vehicle will carry only the specified cargo set by prop15.

To handle the bug in 1), the cargo mask has to be set explicitly for the vehicle´s (single) cargo type, which makes no sense at all if the vehicle shouldn´t be refittable in the first place, but is marked in addition now as "refittable to:" in the purchase menu.