Prevent chronoshifting into shroud

OpenRa.Game/Orders/ChronoshiftDestinationOrderGenerator.cs

@@ -35,6 +35,9 @@ namespace OpenRa.Game.Orders
 
 		public Cursor GetCursor(int2 xy, MouseInput mi)
 		{
+			if (!Game.LocalPlayer.Shroud.IsExplored(xy))
+				return Cursor.MoveBlocked;
+			
 			var movement = self.traits.WithInterface<IMovement>().FirstOrDefault();
 			return (movement.CanEnterCell(xy)) ? Cursor.Chronoshift : Cursor.MoveBlocked;
 		}

OpenRa.Game/Shroud.cs

@@ -14,6 +14,11 @@ namespace OpenRa.Game
 		Sprite[,] sprites = new Sprite[128, 128];
 		bool dirty;
 
+		public bool IsExplored(int2 xy)
+		{
+			return explored[ xy.X, xy.Y ];
+		}
+		
 		public void Explore(Actor a)
 		{
 			foreach (var t in Game.FindTilesInCircle((1f / Game.CellSize * a.CenterLocation).ToInt2(), a.Info.Sight))

OpenRa.Game/Traits/Chronoshiftable.cs

@@ -46,6 +46,9 @@ namespace OpenRa.Game.Traits
 			var movement = self.traits.WithInterface<IMovement>().FirstOrDefault();
 			if (order.OrderString == "Chronoshift" && movement.CanEnterCell(order.TargetLocation))
 			{
+				// Cannot chronoshift into unexplored location
+				if (!Game.LocalPlayer.Shroud.IsExplored(order.TargetLocation))
+					return;
 					
 				// Set up return-to-sender info
 				chronoshiftOrigin = self.Location;