Merge tag '14.0-beta2' into jgrpp

# Conflicts:
#	CMakeLists.txt
#	src/cargotype.cpp
#	src/console_cmds.cpp
#	src/graph_gui.cpp
#	src/industry_cmd.cpp
#	src/industrytype.h
#	src/misc_gui.cpp
#	src/network/network_client.cpp
#	src/newgrf.cpp
#	src/newgrf_town.cpp
#	src/object_cmd.cpp
#	src/openttd.cpp
#	src/pathfinder/water_regions.cpp
#	src/saveload/saveload.cpp
#	src/saveload/saveload.h
#	src/table/build_industry.h
#	src/table/engines.h
#	src/vehicle.cpp
#	src/vehicle_cmd.cpp
#	src/vehicle_gui.cpp

src/aircraft_cmd.cpp

@@ -319,11 +319,16 @@ CommandCost CmdBuildAircraft(TileIndex tile, DoCommandFlag flags, const Engine *
 
 		v->cargo_cap = avi->passenger_capacity;
 		v->refit_cap = 0;
-		u->cargo_cap = avi->mail_capacity;
 		u->refit_cap = 0;
 
 		v->cargo_type = e->GetDefaultCargoType();
-		u->cargo_type = CT_MAIL;
+		assert(IsValidCargoID(v->cargo_type));
+
+		CargoID mail = GetCargoIDByLabel(CT_MAIL);
+		if (IsValidCargoID(mail)) {
+			u->cargo_type = mail;
+			u->cargo_cap = avi->mail_capacity;
+		}
 
 		v->name.clear();
 		v->last_station_visited = INVALID_STATION;