Fix ProximityExternalCondition ignoring the owner change event

OpenRA.Mods.Common/Traits/Conditions/ExternalCondition.cs

@@ -38,7 +38,7 @@ public class ExternalConditionInfo : TraitInfo
 		public override object Create(ActorInitializer init) { return new ExternalCondition(this); }
 	}
 
-	public class ExternalCondition : ITick, INotifyCreated
+	public class ExternalCondition : ITick, INotifyCreated, INotifyOwnerChanged
 	{
 		readonly struct TimedToken
 		{
@@ -222,6 +222,12 @@ void ITick.Tick(Actor self)
 
 		bool Notifies(IConditionTimerWatcher watcher) { return watcher.Condition == Info.Condition; }
 
+		void INotifyOwnerChanged.OnOwnerChanged(Actor self, Player oldOwner, Player newOwner)
+		{
+			foreach (var pair in self.World.ActorsWithTrait<INotifyProximityOwnerChanged>())
+				pair.Trait.OnProximityOwnerChanged(self, oldOwner, newOwner);
+		}
+
 		void INotifyCreated.Created(Actor self)
 		{
 			watchers = self.TraitsImplementing<IConditionTimerWatcher>().Where(Notifies).ToArray();

OpenRA.Mods.Common/Traits/Conditions/ProximityExternalCondition.cs

@@ -42,7 +42,7 @@ public class ProximityExternalConditionInfo : ConditionalTraitInfo
 		public override object Create(ActorInitializer init) { return new ProximityExternalCondition(init.Self, this); }
 	}
 
-	public class ProximityExternalCondition : ConditionalTrait<ProximityExternalConditionInfo>, ITick, INotifyAddedToWorld, INotifyRemovedFromWorld, INotifyOtherProduction
+	public class ProximityExternalCondition : ConditionalTrait<ProximityExternalConditionInfo>, ITick, INotifyAddedToWorld, INotifyRemovedFromWorld, INotifyOtherProduction, INotifyProximityOwnerChanged
 	{
 		readonly Actor self;
 
@@ -123,19 +123,18 @@ void ActorEntered(Actor a)
 
 		public void UnitProducedByOther(Actor self, Actor producer, Actor produced, string productionType, TypeDictionary init)
 		{
-			// If the produced Actor doesn't occupy space, it can't be in range
+			// If the produced Actor doesn't occupy space, it can't be in range.
 			if (produced.OccupiesSpace == null)
 				return;
 
-			// We don't grant conditions when disabled
+			// We don't grant conditions when disabled.
 			if (IsTraitDisabled)
 				return;
 
-			// Work around for actors produced within the region not triggering until the second tick
+			// Work around for actors produced within the region not triggering until the second tick.
 			if ((produced.CenterPosition - self.CenterPosition).HorizontalLengthSquared <= Info.Range.LengthSquared)
 			{
-				var stance = self.Owner.RelationshipWith(produced.Owner);
-				if (!Info.ValidRelationships.HasRelationship(stance))
+				if (!Info.ValidRelationships.HasRelationship(self.Owner.RelationshipWith(produced.Owner)))
 					return;
 
 				var external = produced.TraitsImplementing<ExternalCondition>()
@@ -159,5 +158,36 @@ void ActorExited(Actor a)
 				if (external.TryRevokeCondition(a, self, token))
 					break;
 		}
+
+		void INotifyProximityOwnerChanged.OnProximityOwnerChanged(Actor actor, Player oldOwner, Player newOwner)
+		{
+			// If the Actor doesn't occupy space, it can't be in range.
+			if (actor.OccupiesSpace == null)
+				return;
+
+			// We don't grant conditions when disabled.
+			if (IsTraitDisabled)
+				return;
+
+			// Work around for actors changin owner within the region.
+			if ((actor.CenterPosition - self.CenterPosition).HorizontalLengthSquared <= Info.Range.LengthSquared)
+			{
+				var hasRelationship = Info.ValidRelationships.HasRelationship(self.Owner.RelationshipWith(actor.Owner));
+				var contains = tokens.TryGetValue(actor, out var token);
+				if (hasRelationship && !contains)
+				{
+					var external = actor.TraitsImplementing<ExternalCondition>().FirstOrDefault(t => t.Info.Condition == Info.Condition && t.CanGrantCondition(self));
+					if (external != null)
+						tokens[actor] = external.GrantCondition(actor, self);
+				}
+				else if (!hasRelationship && contains)
+				{
+					tokens.Remove(actor);
+					foreach (var external in actor.TraitsImplementing<ExternalCondition>())
+						if (external.TryRevokeCondition(actor, self, token))
+							break;
+				}
+			}
+		}
 	}
 }

OpenRA.Mods.Common/TraitsInterfaces.cs

@@ -177,6 +177,7 @@ public interface INotifyParachute { void OnParachute(Actor self); void OnLanded(
 
 	[RequireExplicitImplementation]
 	public interface INotifyCapture { void OnCapture(Actor self, Actor captor, Player oldOwner, Player newOwner, BitSet<CaptureType> captureTypes); }
+	public interface INotifyProximityOwnerChanged { void OnProximityOwnerChanged(Actor actor, Player oldOwner, Player newOwner); }
 	public interface INotifyDiscovered { void OnDiscovered(Actor self, Player discoverer, bool playNotification); }
 	public interface IRenderActorPreviewInfo : ITraitInfoInterface { IEnumerable<IActorPreview> RenderPreview(ActorPreviewInitializer init); }
 	public interface ICruiseAltitudeInfo : ITraitInfoInterface { WDist GetCruiseAltitude(); }