Don't order transports for incapable factions.

If these orders can't be fulfilled for the faction it will prevent the
faction from ordering any non-reserve aircraft since transports are
given priority after reserve missions, and they'll never be fulfillable.
As such, no non-reserve aircraft will ever be purchased for factions
without transport aircraft.

Factions without transport aircraft are screwed in other ways, but this
will fix their air planning for campaigns that aren't dependent on
airlift.

changelog.md

@@ -32,6 +32,7 @@ Saves from 3.x are not compatible with 4.0.
 ## Fixes
 
 * **[Campaign AI]** Fix procurement for factions that lack some unit types.
+* **[Campaign AI]** Fix auto purchase of aircraft for factions that have no transport aircraft.
 * **[Mission Generation]** Fixed problem with mission load when control point name contained an apostrophe.
 * **[Mission Generation]** Fixed EWR group names so they contribute to Skynet again.
 * **[Mission Generation]** Fixed duplicate name error when generating convoys and cargo ships when creating manual transfers after loading a game.

game/squadrons.py

@@ -368,6 +368,13 @@ class AirWing:
     def squadrons_for(self, aircraft: AircraftType) -> Sequence[Squadron]:
         return self.squadrons[aircraft]
 
+    def can_auto_plan(self, task: FlightType) -> bool:
+        try:
+            next(self.auto_assignable_for_task(task))
+            return True
+        except StopIteration:
+            return False
+
     def auto_assignable_for_task(self, task: FlightType) -> Iterator[Squadron]:
         for squadron in self.iter_squadrons():
             if squadron.can_auto_assign(task):

game/transfers.py

@@ -592,6 +592,9 @@ class PendingTransfers:
 
     def order_airlift_assets(self) -> None:
         for control_point in self.game.theater.controlpoints:
+            if self.game.air_wing_for(control_point.captured).can_auto_plan(
+                FlightType.TRANSPORT
+            ):
                 self.order_airlift_assets_at(control_point)
 
     @staticmethod

gen/flights/ai_flight_planner.py

@@ -604,14 +604,7 @@ class CoalitionMissionPlanner:
         also possible for the player to exclude mission types from their squadron
         designs.
         """
-        all_compatible = aircraft_for_task(mission_type)
-        for squadron in self.game.air_wing_for(self.is_player).iter_squadrons():
-            if (
-                squadron.aircraft in all_compatible
-                and mission_type in squadron.auto_assignable_mission_types
-            ):
-                return True
-        return False
+        return self.game.air_wing_for(self.is_player).can_auto_plan(mission_type)
 
     def critical_missions(self) -> Iterator[ProposedMission]:
         """Identifies the most important missions to plan this turn.