Fix carryalls telling carryables to unreserve when they are reserved for a different carryall;

Reserve carryable in FreeActorWithDelivery

OpenRA.Mods.D2k/Traits/Buildings/FreeActorWithDelivery.cs

@@ -64,7 +64,9 @@ namespace OpenRA.Mods.D2k.Traits
 			if (clientInitialActivity != null)
 				cargo.QueueActivity(Game.CreateObject<Activity>(clientInitialActivity));
 
-			cargo.Trait<Carryable>().Destination = location;
+			var carryable = cargo.Trait<Carryable>();
+			carryable.Destination = location;
+			carryable.Reserve(carrier);
 
 			carrier.Trait<Carryall>().AttachCarryable(cargo);
 

OpenRA.Mods.D2k/Traits/Carryable.cs

@@ -116,6 +116,9 @@ namespace OpenRA.Mods.D2k.Traits
 
 		public bool Reserve(Actor carrier)
 		{
+			if (Reserved)
+				return false;
+
 			if ((self.Location - Destination).Length < info.MinDistance)
 			{
 				MovementCancelled(self);

OpenRA.Mods.D2k/Traits/Carryall.cs

@@ -122,6 +122,9 @@ namespace OpenRA.Mods.D2k.Traits
 		// Reserve the carryable so its ours exclusively
 		public bool ReserveCarryable(Actor carryable)
 		{
+			if (Carrying != null)
+				return false;
+
 			if (carryable.Trait<Carryable>().Reserve(self))
 			{
 				Carrying = carryable;
@@ -144,6 +147,7 @@ namespace OpenRA.Mods.D2k.Traits
 			}
 
 			IsBusy = false;
+			Carrying = null;
 		}
 
 		// INotifyKilled
@@ -177,6 +181,7 @@ namespace OpenRA.Mods.D2k.Traits
 		// Called when released
 		public void CarryableReleased()
 		{
+			IsBusy = false;
 			IsCarrying = false;
 			anim = null;
 		}