Move AbortOnResupply to AttackAircraft

Additionally, if AbortOnResupply is set to 'true',
abort FlyAttack right away when queueing ReturnToBase.

OpenRA.Mods.Common/UpdateRules/Rules/20190314/MoveAbortOnResupply.cs

@@ -0,0 +1,60 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007-2019 The OpenRA Developers (see AUTHORS)
+ * This file is part of OpenRA, which is free software. It is made
+ * available to you under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, either version 3 of
+ * the License, or (at your option) any later version. For more
+ * information, see COPYING.
+ */
+#endregion
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace OpenRA.Mods.Common.UpdateRules.Rules
+{
+	public class MoveAbortOnResupply : UpdateRule
+	{
+		public override string Name { get { return "Moved AbortOnResupply from Aircraft to AttackAircraft"; } }
+		public override string Description
+		{
+			get
+			{
+				return "AbortOnResupply boolean was moved to AttackAircraft.";
+			}
+		}
+
+		public override IEnumerable<string> UpdateActorNode(ModData modData, MiniYamlNode actorNode)
+		{
+			var aircraft = actorNode.LastChildMatching("Aircraft");
+			var attackAircraft = actorNode.ChildrenMatching("AttackAircraft");
+
+			if (aircraft != null)
+			{
+				var abortOnResupply = aircraft.LastChildMatching("AbortOnResupply");
+				if (abortOnResupply == null)
+					yield break;
+
+				// Only add field to AttackAircraft if explicitly set to 'false'
+				if (!abortOnResupply.NodeValue<bool>())
+				{
+					if (attackAircraft.Any())
+						foreach (var a in attackAircraft)
+							a.AddNode(abortOnResupply);
+					else
+					{
+						var newAttackAircraft = new MiniYamlNode("AttackAircraft", "");
+						newAttackAircraft.AddNode(abortOnResupply);
+						actorNode.AddNode(newAttackAircraft);
+					}
+				}
+
+				aircraft.RemoveNode(abortOnResupply);
+			}
+
+			yield break;
+		}
+	}
+}