Avoid landing-dances when issuing mixed full/empty aircraft RTB orders.

OpenRA.Mods.Common/Activities/Air/HeliReturnToBase.cs

@@ -19,10 +19,12 @@ namespace OpenRA.Mods.Common.Activities
 	public class HeliReturnToBase : Activity
 	{
 		readonly Aircraft heli;
+		readonly bool alwaysLand;
 
-		public HeliReturnToBase(Actor self)
+		public HeliReturnToBase(Actor self, bool alwaysLand = true)
 		{
 			heli = self.Trait<Aircraft>();
+			this.alwaysLand = alwaysLand;
 		}
 
 		public Actor ChooseHelipad(Actor self)
@@ -68,11 +70,13 @@ namespace OpenRA.Mods.Common.Activities
 				}
 			}
 
-			heli.MakeReservation(dest);
-
 			var exit = dest.Info.TraitInfos<ExitInfo>().FirstOrDefault();
 			var offset = (exit != null) ? exit.SpawnOffset : WVec.Zero;
 
+			if (ShouldLandAtBuilding(self, dest))
+			{
+				heli.MakeReservation(dest);
+
 				return ActivityUtils.SequenceActivities(
 					new HeliFly(self, Target.FromPos(dest.CenterPosition + offset)),
 					new Turn(self, initialFacing),
@@ -80,5 +84,22 @@ namespace OpenRA.Mods.Common.Activities
 					new ResupplyAircraft(self),
 					NextActivity);
 			}
+
+			return ActivityUtils.SequenceActivities(
+				new HeliFly(self, Target.FromPos(dest.CenterPosition + offset)),
+				NextActivity);
+		}
+
+		bool ShouldLandAtBuilding(Actor self, Actor dest)
+		{
+			if (alwaysLand)
+				return true;
+
+			if (heli.Info.RepairBuildings.Contains(dest.Info.Name) && self.GetDamageState() != DamageState.Undamaged)
+				return true;
+
+			return heli.Info.RearmBuildings.Contains(dest.Info.Name) && self.TraitsImplementing<AmmoPool>()
+					.Any(p => !p.Info.SelfReloads && !p.FullAmmo());
+		}
 	}
 }

OpenRA.Mods.Common/Activities/Air/ReturnToBase.cs

@@ -22,13 +22,15 @@ namespace OpenRA.Mods.Common.Activities
 	{
 		readonly Aircraft plane;
 		readonly AircraftInfo planeInfo;
+		readonly bool alwaysLand;
 		bool isCalculated;
 		Actor dest;
 		WPos w1, w2, w3;
 
-		public ReturnToBase(Actor self, Actor dest = null)
+		public ReturnToBase(Actor self, Actor dest = null, bool alwaysLand = true)
 		{
 			this.dest = dest;
+			this.alwaysLand = alwaysLand;
 			plane = self.Trait<Aircraft>();
 			planeInfo = self.Info.TraitInfo<AircraftInfo>();
 		}
@@ -51,8 +53,6 @@ namespace OpenRA.Mods.Common.Activities
 			if (dest == null)
 				return;
 
-			plane.MakeReservation(dest);
-
 			var landPos = dest.CenterPosition;
 			var altitude = planeInfo.CruiseAltitude.Length;
 
@@ -94,6 +94,18 @@ namespace OpenRA.Mods.Common.Activities
 			isCalculated = true;
 		}
 
+		bool ShouldLandAtBuilding(Actor self, Actor dest)
+		{
+			if (alwaysLand)
+				return true;
+
+			if (planeInfo.RepairBuildings.Contains(dest.Info.Name) && self.GetDamageState() != DamageState.Undamaged)
+				return true;
+
+			return planeInfo.RearmBuildings.Contains(dest.Info.Name) && self.TraitsImplementing<AmmoPool>()
+					.Any(p => !p.Info.SelfReloads && !p.FullAmmo());
+		}
+
 		public override Activity Tick(Actor self)
 		{
 			if (IsCanceled || self.IsDead)
@@ -128,8 +140,15 @@ namespace OpenRA.Mods.Common.Activities
 
 			// Fix a problem when the airplane is send to resupply near the airport
 			landingProcedures.Add(new Fly(self, Target.FromPos(w3), WDist.Zero, new WDist(turnRadius / 2)));
+
+			if (ShouldLandAtBuilding(self, dest))
+			{
+				plane.MakeReservation(dest);
+
 				landingProcedures.Add(new Land(self, Target.FromActor(dest)));
 				landingProcedures.Add(new ResupplyAircraft(self));
+			}
+
 			landingProcedures.Add(NextActivity);
 
 			return ActivityUtils.SequenceActivities(landingProcedures.ToArray());

OpenRA.Mods.Common/Traits/Air/Aircraft.cs

@@ -618,9 +618,9 @@ namespace OpenRA.Mods.Common.Traits
 				UnReserve();
 				self.CancelActivity();
 				if (IsPlane)
-					self.QueueActivity(new ReturnToBase(self));
+					self.QueueActivity(new ReturnToBase(self, null, false));
 				else
-					self.QueueActivity(new HeliReturnToBase(self));
+					self.QueueActivity(new HeliReturnToBase(self, false));
 
 				self.QueueActivity(new ResupplyAircraft(self));
 			}