From b1b74c13c37d68e317f68dee643d0353a914d1e1 Mon Sep 17 00:00:00 2001
From: abcdefg30 <alphabet@streber24.de>
Date: Fri, 7 Feb 2020 12:38:57 +0100
Subject: [PATCH] Ensure that we never tick an activity before calling
 OnFirstRun

---
 OpenRA.Game/Activities/Activity.cs | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/OpenRA.Game/Activities/Activity.cs b/OpenRA.Game/Activities/Activity.cs
index b4115edd5e..452267bd65 100644
--- a/OpenRA.Game/Activities/Activity.cs
+++ b/OpenRA.Game/Activities/Activity.cs
@@ -83,6 +83,7 @@ namespace OpenRA.Activities
 		public bool ChildHasPriority { get; protected set; }
 		public bool IsCanceling { get { return State == ActivityState.Canceling; } }
 		bool finishing;
+		bool firstRunCompleted;
 		bool lastRun;
 
 		public Activity()
@@ -99,9 +100,13 @@ namespace OpenRA.Activities
 			if (State == ActivityState.Queued)
 			{
 				OnFirstRun(self);
+				firstRunCompleted = true;
 				State = ActivityState.Active;
 			}
 
+			if (!firstRunCompleted)
+				throw new InvalidOperationException("Actor {0} attempted to tick activity {1} before running its OnFirstRun method.".F(self, GetType()));
+
 			// Only run the parent tick when the child is done.
 			// We must always let the child finish on its own before continuing.
 			if (ChildHasPriority)