From ff9db0bf7a067166edbf7039b05105d7649b9653 Mon Sep 17 00:00:00 2001
From: Paul Chote <pchote@users.noreply.github.com>
Date: Thu, 20 Jun 2019 20:42:57 +0000
Subject: [PATCH] Reset RequestedTargets that are cancelled before the first
 attack tick.

---
 .../Activities/Move/AttackMoveActivity.cs     |  5 +--
 .../Traits/Attack/AttackBase.cs               |  7 +++--
 .../Traits/Attack/AttackFollow.cs             | 31 ++++++++++++-------
 3 files changed, 26 insertions(+), 17 deletions(-)

diff --git a/OpenRA.Mods.Common/Activities/Move/AttackMoveActivity.cs b/OpenRA.Mods.Common/Activities/Move/AttackMoveActivity.cs
index 6c873dd121..7ad572ae3e 100644
--- a/OpenRA.Mods.Common/Activities/Move/AttackMoveActivity.cs
+++ b/OpenRA.Mods.Common/Activities/Move/AttackMoveActivity.cs
@@ -63,8 +63,9 @@ namespace OpenRA.Mods.Common.Activities
 					var attackBases = autoTarget.ActiveAttackBases;
 					foreach (var ab in attackBases)
 					{
-						QueueChild(self, ab.GetAttackActivity(self, target, true, false));
-						ab.OnQueueAttackActivity(self, target, false, true, false);
+						var activity = ab.GetAttackActivity(self, target, true, false);
+						QueueChild(self, activity);
+						ab.OnQueueAttackActivity(self, activity, target, true, false);
 					}
 
 					// Make sure to continue moving when the attack activities have finished.
diff --git a/OpenRA.Mods.Common/Traits/Attack/AttackBase.cs b/OpenRA.Mods.Common/Traits/Attack/AttackBase.cs
index f1182afad6..524e4d0364 100644
--- a/OpenRA.Mods.Common/Traits/Attack/AttackBase.cs
+++ b/OpenRA.Mods.Common/Traits/Attack/AttackBase.cs
@@ -392,11 +392,12 @@ namespace OpenRA.Mods.Common.Traits
 			if (!queued)
 				self.CancelActivity();
 
-			self.QueueActivity(GetAttackActivity(self, target, allowMove, forceAttack));
-			OnQueueAttackActivity(self, target, queued, allowMove, forceAttack);
+			var activity = GetAttackActivity(self, target, allowMove, forceAttack);
+			self.QueueActivity(activity);
+			OnQueueAttackActivity(self, activity, target, allowMove, forceAttack);
 		}
 
-		public virtual void OnQueueAttackActivity(Actor self, Target target, bool queued, bool allowMove, bool forceAttack) { }
+		public virtual void OnQueueAttackActivity(Actor self, Activity activity, Target target, bool allowMove, bool forceAttack) { }
 
 		public bool IsReachableTarget(Target target, bool allowMove)
 		{
diff --git a/OpenRA.Mods.Common/Traits/Attack/AttackFollow.cs b/OpenRA.Mods.Common/Traits/Attack/AttackFollow.cs
index 38d80c8a69..4a7b9c039d 100644
--- a/OpenRA.Mods.Common/Traits/Attack/AttackFollow.cs
+++ b/OpenRA.Mods.Common/Traits/Attack/AttackFollow.cs
@@ -37,8 +37,8 @@ namespace OpenRA.Mods.Common.Traits
 
 		Mobile mobile;
 		AutoTarget autoTarget;
-		int requestedTargetLastTick;
 		bool requestedForceAttack;
+		Activity requestedTargetPresetForActivity;
 		bool opportunityForceAttack;
 		bool opportunityTargetIsPersistentTarget;
 
@@ -46,7 +46,7 @@ namespace OpenRA.Mods.Common.Traits
 		{
 			RequestedTarget = target;
 			requestedForceAttack = isForceAttack;
-			requestedTargetLastTick = self.World.WorldTick;
+			requestedTargetPresetForActivity = null;
 		}
 
 		public void ClearRequestedTarget()
@@ -59,6 +59,7 @@ namespace OpenRA.Mods.Common.Traits
 			}
 
 			RequestedTarget = Target.Invalid;
+			requestedTargetPresetForActivity = null;
 		}
 
 		public AttackFollow(Actor self, AttackFollowInfo info)
@@ -100,12 +101,19 @@ namespace OpenRA.Mods.Common.Traits
 				opportunityTargetIsPersistentTarget = false;
 			}
 
-			if (requestedTargetLastTick != self.World.WorldTick)
+			if (requestedTargetPresetForActivity != null)
 			{
-				// Activities tick before traits, so if we are here it means the activity didn't run
-				// (either queued next or already cancelled) and we need to recalculate the target ourself
-				bool targetIsHiddenActor;
-				RequestedTarget = RequestedTarget.Recalculate(self.Owner, out targetIsHiddenActor);
+				// RequestedTarget was set by OnQueueAttackActivity in preparation for a queued activity
+				// requestedTargetPresetForActivity will be cleared once the activity starts running and calls UpdateRequestedTarget
+				if (self.CurrentActivity != null && self.CurrentActivity.NextActivity == requestedTargetPresetForActivity)
+				{
+					bool targetIsHiddenActor;
+					RequestedTarget = RequestedTarget.Recalculate(self.Owner, out targetIsHiddenActor);
+				}
+
+				// Requested activity has been canceled
+				else
+					ClearRequestedTarget();
 			}
 
 			// Can't fire on anything
@@ -148,16 +156,15 @@ namespace OpenRA.Mods.Common.Traits
 			return new AttackActivity(self, newTarget, allowMove, forceAttack);
 		}
 
-		public override void OnQueueAttackActivity(Actor self, Target target, bool queued, bool allowMove, bool forceAttack)
+		public override void OnQueueAttackActivity(Actor self, Activity activity, Target target, bool allowMove, bool forceAttack)
 		{
-			// If not queued we know that the attack activity will run next
 			// We can improve responsiveness for turreted actors by preempting
-			// the last order (usually a move) and set the target immediately
-			if (!queued)
+			// the last order (usually a move) and setting the target immediately
+			if (self.CurrentActivity != null && self.CurrentActivity.NextActivity == activity)
 			{
 				RequestedTarget = target;
 				requestedForceAttack = forceAttack;
-				requestedTargetLastTick = self.World.WorldTick;
+				requestedTargetPresetForActivity = activity;
 			}
 		}