Restrict transfers to connected bases.

https://github.com/Khopa/dcs_liberation/issues/824

game/theater/controlpoint.py

@@ -8,7 +8,7 @@ from abc import ABC, abstractmethod
 from dataclasses import dataclass, field
 from enum import Enum
 from functools import total_ordering
-from typing import Any, Dict, Iterator, List, Optional, TYPE_CHECKING, Type
+from typing import Any, Dict, Iterator, List, Optional, Set, TYPE_CHECKING, Type
 
 from dcs.mapping import Point
 from dcs.ships import (
@@ -292,6 +292,23 @@ class ControlPoint(MissionTarget, ABC):
     def is_global(self):
         return not self.connected_points
 
+    def transitive_connected_friendly_points(
+        self, seen: Optional[Set[ControlPoint]] = None
+    ) -> List[ControlPoint]:
+        if seen is None:
+            seen = {self}
+
+        connected = []
+        for cp in self.connected_points:
+            if cp.captured != self.captured:
+                continue
+            if cp in seen:
+                continue
+            seen.add(cp)
+            connected.append(cp)
+            connected.extend(cp.transitive_connected_friendly_points(seen))
+        return connected
+
     @property
     def is_carrier(self):
         """

game/theater/supplyroutes.py

@@ -0,0 +1,23 @@
+from __future__ import annotations
+
+from typing import Iterator, List, Optional
+
+from game.theater.controlpoint import ControlPoint
+
+
+class SupplyRoute:
+    def __init__(self, control_points: List[ControlPoint]) -> None:
+        self.control_points = control_points
+
+    def __contains__(self, item: ControlPoint) -> bool:
+        return item in self.control_points
+
+    def __iter__(self) -> Iterator[ControlPoint]:
+        yield from self.control_points
+
+    @classmethod
+    def for_control_point(cls, control_point: ControlPoint) -> Optional[SupplyRoute]:
+        connected_friendly_points = control_point.transitive_connected_friendly_points()
+        if not connected_friendly_points:
+            return None
+        return SupplyRoute([control_point] + connected_friendly_points)