Don't crash on multiple Attack* traits

This is important for actors that use upgrades to switch between attack types.

OpenRA.Mods.Common/Activities/Attack.cs

@@ -8,6 +8,7 @@
  */
 #endregion
 
+using System;
 using System.Linq;
 using OpenRA.Activities;
 using OpenRA.Mods.Common.Traits;
@@ -18,8 +19,11 @@ namespace OpenRA.Mods.Common.Activities
 	/* non-turreted attack */
 	public class Attack : Activity
 	{
+		[Flags]
+		enum AttackStatus { UnableToAttack, NeedsToTurn, NeedsToMove, Attacking }
+
 		protected readonly Target Target;
-		readonly AttackBase attack;
+		readonly AttackBase[] attackTraits;
 		readonly IMove move;
 		readonly IFacing facing;
 		readonly IPositionable positionable;
@@ -27,6 +31,9 @@ namespace OpenRA.Mods.Common.Activities
 
 		WDist minRange;
 		WDist maxRange;
+		Activity turnActivity;
+		Activity moveActivity;
+		AttackStatus attackStatus = AttackStatus.UnableToAttack;
 
 		public Attack(Actor self, Target target, bool allowMovement, bool forceAttack)
 		{
@@ -34,7 +41,7 @@ namespace OpenRA.Mods.Common.Activities
 
 			this.forceAttack = forceAttack;
 
-			attack = self.Trait<AttackBase>();
+			attackTraits = self.TraitsImplementing<AttackBase>().ToArray();
 			facing = self.Trait<IFacing>();
 			positionable = self.Trait<IPositionable>();
 
@@ -43,9 +50,25 @@ namespace OpenRA.Mods.Common.Activities
 
 		public override Activity Tick(Actor self)
 		{
-			var ret = InnerTick(self, attack);
+			turnActivity = moveActivity = null;
-			attack.IsAttacking = ret == this;
+			attackStatus = AttackStatus.UnableToAttack;
-			return ret;
+
+			foreach (var attack in attackTraits.Where(x => !x.IsTraitDisabled))
+			{
+				var activity = InnerTick(self, attack);
+				attack.IsAttacking = activity == this;
+			}
+
+			if (attackStatus.HasFlag(AttackStatus.Attacking))
+				return this;
+
+			if (attackStatus.HasFlag(AttackStatus.NeedsToTurn))
+				return turnActivity;
+
+			if (attackStatus.HasFlag(AttackStatus.NeedsToMove))
+				return moveActivity;
+
+			return NextActivity;
 		}
 
 		protected virtual Activity InnerTick(Actor self, AttackBase attack)
@@ -81,13 +104,21 @@ namespace OpenRA.Mods.Common.Activities
 				// Try to move within range, drop the target otherwise
 				if (move == null)
 					return NextActivity;
-				return ActivityUtils.SequenceActivities(move.MoveWithinRange(Target, minRange, maxRange), this);
+
+				attackStatus |= AttackStatus.NeedsToMove;
+				moveActivity = ActivityUtils.SequenceActivities(move.MoveWithinRange(Target, minRange, maxRange), this);
+				return NextActivity;
 			}
 
 			var desiredFacing = (Target.CenterPosition - self.CenterPosition).Yaw.Facing;
 			if (facing.Facing != desiredFacing)
-				return ActivityUtils.SequenceActivities(new Turn(self, desiredFacing), this);
+			{
+				attackStatus |= AttackStatus.NeedsToTurn;
+				turnActivity = ActivityUtils.SequenceActivities(new Turn(self, desiredFacing), this);
+				return NextActivity;
+			}
 
+			attackStatus |= AttackStatus.Attacking;
 			attack.DoAttack(self, Target, armaments);
 
 			return this;

OpenRA.Mods.Common/Traits/CombatDebugOverlay.cs

@@ -27,17 +27,15 @@ namespace OpenRA.Mods.Common.Traits
 	public class CombatDebugOverlay : IPostRender, INotifyDamage, INotifyCreated
 	{
 		readonly DeveloperMode devMode;
-
 		readonly HealthInfo healthInfo;
+		readonly Lazy<BodyOrientation> coords;
+
 		IBlocksProjectiles[] allBlockers;
-		Lazy<AttackBase> attack;
-		Lazy<BodyOrientation> coords;
 
 		public CombatDebugOverlay(Actor self)
 		{
 			healthInfo = self.Info.TraitInfoOrDefault<HealthInfo>();
-			attack = Exts.Lazy(() => self.TraitOrDefault<AttackBase>());
+			coords = Exts.Lazy(self.Trait<BodyOrientation>);
-			coords = Exts.Lazy(() => self.Trait<BodyOrientation>());
 
 			var localPlayer = self.World.LocalPlayer;
 			devMode = localPlayer != null ? localPlayer.PlayerActor.Trait<DeveloperMode>() : null;
@@ -71,14 +69,16 @@ namespace OpenRA.Mods.Common.Traits
 				TargetLineRenderable.DrawTargetMarker(wr, hc, hb);
 			}
 
-			// No armaments to draw
+			foreach (var attack in self.TraitsImplementing<AttackBase>().Where(x => !x.IsTraitDisabled))
-			if (attack.Value == null)
+				DrawArmaments(self, attack, wr, wcr, iz);
-				return;
+		}
 
+		void DrawArmaments(Actor self, AttackBase attack, WorldRenderer wr, RgbaColorRenderer wcr, float iz)
+		{
 			var c = Color.White;
 
 			// Fire ports on garrisonable structures
-			var garrison = attack.Value as AttackGarrisoned;
+			var garrison = attack as AttackGarrisoned;
 			if (garrison != null)
 			{
 				var bodyOrientation = coords.Value.QuantizeOrientation(self, self.Orientation);
@@ -98,7 +98,7 @@ namespace OpenRA.Mods.Common.Traits
 				return;
 			}
 
-			foreach (var a in attack.Value.Armaments)
+			foreach (var a in attack.Armaments)
 			{
 				foreach (var b in a.Barrels)
 				{