Simplify special exits of several acitivities.

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

@@ -114,8 +114,8 @@ namespace OpenRA.Mods.Common.Activities
 			// If all valid weapons have depleted their ammo and Rearmable trait exists, return to RearmActor to reload and then resume the activity
 			if (rearmable != null && !useLastVisibleTarget && attackAircraft.Armaments.All(x => x.IsTraitPaused || !x.Weapon.IsValidAgainst(target, self.World, self)))
 			{
-				QueueChild(new ReturnToBase(self, aircraft.Info.AbortOnResupply));
-				return false;
+				QueueChild(new ReturnToBase(self));
+				return aircraft.Info.AbortOnResupply;
 			}
 
 			var pos = self.CenterPosition;

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

@@ -117,9 +117,8 @@ namespace OpenRA.Mods.Common.Activities
 				// Cannot land so fly towards the last target location instead.
 				if (!newLocation.HasValue)
 				{
-					Cancel(self, true);
 					QueueChild(aircraft.MoveTo(landingCell, 0));
-					return false;
+					return true;
 				}
 
 				if (newLocation.Value != landingCell)

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

@@ -25,16 +25,13 @@ namespace OpenRA.Mods.Common.Activities
 		readonly RepairableInfo repairableInfo;
 		readonly Rearmable rearmable;
 		readonly bool alwaysLand;
-		readonly bool abortOnResupply;
-		bool resupplied;
 		Actor dest;
 		int facing = -1;
 
-		public ReturnToBase(Actor self, bool abortOnResupply, Actor dest = null, bool alwaysLand = true)
+		public ReturnToBase(Actor self, Actor dest = null, bool alwaysLand = true)
 		{
 			this.dest = dest;
 			this.alwaysLand = alwaysLand;
-			this.abortOnResupply = abortOnResupply;
 			aircraft = self.Trait<Aircraft>();
 			repairableInfo = self.Info.TraitInfoOrDefault<RepairableInfo>();
 			rearmable = self.TraitOrDefault<Rearmable>();
@@ -73,17 +70,7 @@ namespace OpenRA.Mods.Common.Activities
 			if (aircraft.ForceLanding)
 				return true;
 
-			// If a Cancel was triggered at this point, it's unlikely that previously queued child activities finished,
-			// so 'resupplied' needs to be set to false, else it + abortOnResupply might cause another Cancel
-			// that would cancel any other activities that were queued after the first Cancel was triggered.
-			// TODO: This is a mess, we need to somehow make the activity cancelling a bit less tricky.
-			if (resupplied && IsCanceling)
-				resupplied = false;
-
-			if (resupplied && abortOnResupply)
-				self.CancelActivity();
-
-			if (resupplied || IsCanceling || self.IsDead)
+			if (IsCanceling || self.IsDead)
 				return true;
 
 			if (dest == null || dest.IsDead || !Reservable.IsAvailableFor(dest, self))
@@ -136,11 +123,11 @@ namespace OpenRA.Mods.Common.Activities
 				QueueChild(new Resupply(self, dest, WDist.Zero));
 				if (aircraft.Info.TakeOffOnResupply && !alwaysLand)
 					QueueChild(new TakeOff(self));
-			}
-			else
-				QueueChild(new Fly(self, Target.FromActor(dest)));
 
-			resupplied = true;
+				return true;
+			}
+
+			QueueChild(new Fly(self, Target.FromActor(dest)));
 			return false;
 		}
 	}

OpenRA.Mods.Common/Activities/DeliverResources.cs

@@ -22,8 +22,6 @@ namespace OpenRA.Mods.Common.Activities
 		readonly Harvester harv;
 		readonly Actor targetActor;
 
-		bool isDocking;
-
 		public DeliverResources(Actor self, Actor targetActor = null)
 		{
 			movement = self.Trait<IMove>();
@@ -39,7 +37,7 @@ namespace OpenRA.Mods.Common.Activities
 
 		public override bool Tick(Actor self)
 		{
-			if (IsCanceling || isDocking)
+			if (IsCanceling)
 				return true;
 
 			// Find the nearest best refinery if not explicitly ordered to a specific refinery:
@@ -66,14 +64,8 @@ namespace OpenRA.Mods.Common.Activities
 				return false;
 			}
 
-			if (!isDocking)
-			{
-				QueueChild(new Wait(10));
-				isDocking = true;
-				iao.OnDock(self, this);
-				return false;
-			}
-
+			QueueChild(new Wait(10));
+			iao.OnDock(self, this);
 			return true;
 		}
 	}

OpenRA.Mods.Common/Activities/DeployForGrantedCondition.cs

@@ -20,7 +20,6 @@ namespace OpenRA.Mods.Common.Activities
 		readonly GrantConditionOnDeploy deploy;
 		readonly bool canTurn;
 		readonly bool moving;
-		bool initiated;
 
 		public DeployForGrantedCondition(Actor self, GrantConditionOnDeploy deploy, bool moving = false)
 		{
@@ -38,13 +37,11 @@ namespace OpenRA.Mods.Common.Activities
 
 		public override bool Tick(Actor self)
 		{
-			if (IsCanceling || initiated || (deploy.DeployState != DeployState.Deployed && moving))
+			if (IsCanceling || (deploy.DeployState != DeployState.Deployed && moving))
 				return true;
 
 			QueueChild(new DeployInner(self, deploy));
-
-			initiated = true;
-			return false;
+			return true;
 		}
 	}
 

OpenRA.Mods.Common/Activities/UnloadCargo.cs

@@ -129,13 +129,13 @@ namespace OpenRA.Mods.Common.Activities
 
 			if (!unloadAll || !cargo.CanUnload())
 			{
-				Cancel(self, true);
-
 				if (cargo.Info.AfterUnloadDelay > 0)
 					QueueChild(new Wait(cargo.Info.AfterUnloadDelay, false));
 
 				if (takeOffAfterUnload)
 					QueueChild(new TakeOff(self));
+
+				return true;
 			}
 
 			return false;

OpenRA.Mods.Common/Scripting/Properties/AircraftProperties.cs

@@ -38,7 +38,7 @@ namespace OpenRA.Mods.Common.Scripting
 		[Desc("Return to the base, which is either the destination given, or an auto-selected one otherwise.")]
 		public void ReturnToBase(Actor destination = null)
 		{
-			Self.QueueActivity(new ReturnToBase(Self, false, destination));
+			Self.QueueActivity(new ReturnToBase(Self, destination));
 		}
 
 		[ScriptActorPropertyActivity]

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

@@ -1012,7 +1012,7 @@ namespace OpenRA.Mods.Common.Traits
 				// them to land on a resupplier. For aircraft without it, it makes more sense to land than to idle above a
 				// free resupplier.
 				var forceLand = orderString == "ForceEnter" || !Info.TakeOffOnResupply;
-				self.QueueActivity(order.Queued, new ReturnToBase(self, Info.AbortOnResupply, targetActor, forceLand));
+				self.QueueActivity(order.Queued, new ReturnToBase(self, targetActor, forceLand));
 			}
 			else if (orderString == "Stop")
 			{
@@ -1036,7 +1036,7 @@ namespace OpenRA.Mods.Common.Traits
 
 				// Aircraft with TakeOffOnResupply would immediately take off again, so there's no point in forcing them to land
 				// on a resupplier. For aircraft without it, it makes more sense to land than to idle above a free resupplier.
-				self.QueueActivity(order.Queued, new ReturnToBase(self, Info.AbortOnResupply, null, !Info.TakeOffOnResupply));
+				self.QueueActivity(order.Queued, new ReturnToBase(self, null, !Info.TakeOffOnResupply));
 			}
 			else if (orderString == "Scatter")
 				Nudge(self);

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

@@ -38,7 +38,7 @@ namespace OpenRA.Mods.Common.Traits
 
 			var resupplier = ReturnToBase.ChooseResupplier(self, true);
 			if (resupplier != null)
-				self.QueueActivity(new ReturnToBase(self, aircraftInfo.AbortOnResupply, resupplier));
+				self.QueueActivity(new ReturnToBase(self, resupplier));
 			else
 			{
 				// nowhere to land, pick something friendly and circle over it.