Track visibility modifiers on FrozenActors.

OpenRA.Game/Traits/Player/FrozenActorLayer.cs

@@ -46,7 +46,17 @@ namespace OpenRA.Traits
 		public DamageState DamageState { get; private set; }
 		readonly IHealth health;
 
+		// The Visible flag is tied directly to the actor visibility under the fog.
+		// If Visible is true, the actor is made invisible (via FrozenUnderFog/IDefaultVisibility)
+		// and this FrozenActor is rendered instead.
+		// The Hidden flag covers the edge case that occurs when the backing actor was last "seen"
+		// to be cloaked or otherwise not CanBeViewedByPlayer()ed. Setting Visible to true when
+		// the actor is hidden under the fog would leak the actors position via the tooltips and
+		// AutoTargetability, and keeping Visible as false would cause the actor to be rendered
+		// under the fog.
 		public bool Visible = true;
+		public bool Hidden = false;
+
 		public bool Shrouded { get; private set; }
 		public bool NeedRenderables { get; set; }
 		public IRenderable[] Renderables = NoRenderables;
@@ -101,6 +111,7 @@ namespace OpenRA.Traits
 		{
 			Owner = actor.Owner;
 			TargetTypes = actor.GetEnabledTargetTypes();
+			Hidden = !actor.CanBeViewedByPlayer(viewer);
 
 			if (health != null)
 			{
@@ -145,6 +156,11 @@ namespace OpenRA.Traits
 			NeedRenderables |= Visible && !wasVisible;
 		}
 
+		public void Invalidate()
+		{
+			Owner = null;
+		}
+
 		public void Flash()
 		{
 			flashTicks = 5;

OpenRA.Game/Traits/Target.cs

@@ -80,13 +80,21 @@ namespace OpenRA.Traits
 
 		public bool IsValidFor(Actor targeter)
 		{
-			if (targeter == null || Type == TargetType.Invalid)
+			if (targeter == null)
 				return false;
 
-			if (actor != null && !actor.IsTargetableBy(targeter))
-				return false;
-
-			return true;
+			switch (Type)
+			{
+				case TargetType.Actor:
+					return actor.IsTargetableBy(targeter);
+				case TargetType.FrozenActor:
+					return frozen.IsValid && frozen.Visible && !frozen.Hidden;
+				case TargetType.Invalid:
+					return false;
+				default:
+				case TargetType.Terrain:
+					return true;
+			}
 		}
 
 		// Currently all or nothing.

OpenRA.Mods.Cnc/Traits/FrozenUnderFogUpdatedByGps.cs

@@ -39,6 +39,7 @@ namespace OpenRA.Mods.Cnc.Traits
 		static readonly FrozenActorAction Remove = (fufubg, fal, gps, fa) =>
 		{
 			// Removes the frozen actor. Once done, we no longer need to track GPS updates.
+			fa.Invalidate();
 			fal.Remove(fa);
 			gps.UnregisterForOnGpsRefreshed(fufubg.self, fufubg);
 		};

OpenRA.Mods.Common/Traits/Modifiers/FrozenUnderFog.cs

@@ -68,11 +68,13 @@ namespace OpenRA.Mods.Common.Traits
 			frozenStates = new PlayerDictionary<FrozenState>(self.World, (player, playerIndex) =>
 			{
 				var frozenActor = new FrozenActor(self, footprint, player, startsRevealed);
-				if (startsRevealed)
-					UpdateFrozenActor(self, frozenActor, playerIndex);
 				player.PlayerActor.Trait<FrozenActorLayer>().Add(frozenActor);
 				return new FrozenState(frozenActor) { IsVisible = startsRevealed };
 			});
+
+			if (startsRevealed)
+				for (var playerIndex = 0; playerIndex < frozenStates.Count; playerIndex++)
+					UpdateFrozenActor(self, frozenStates[playerIndex].FrozenActor, playerIndex);
 		}
 
 		void UpdateFrozenActor(Actor self, FrozenActor frozenActor, int playerIndex)

OpenRA.Mods.Common/Widgets/ViewportControllerWidget.cs

@@ -246,26 +246,20 @@ namespace OpenRA.Mods.Common.Widgets
 			}
 
 			var frozen = world.ScreenMap.FrozenActorsAtMouse(world.RenderPlayer, worldPixel)
-				.Where(a => a.TooltipInfo != null && a.IsValid)
+				.Where(a => a.TooltipInfo != null && a.IsValid && a.Visible && !a.Hidden)
 				.WithHighestSelectionPriority(worldPixel);
 
 			if (frozen != null)
 			{
-				var actor = frozen.Actor;
+				FrozenActorTooltip = frozen;
 
-				// HACK: This leaks the cloak state through the fog (cloaked buildings will not show tooltips)
-				if (actor == null || actor.TraitsImplementing<IVisibilityModifier>().All(t => t.IsVisible(actor, world.RenderPlayer)))
-				{
-					FrozenActorTooltip = frozen;
+				// HACK: This leaks the tooltip state through the fog
+				// This will cause issues for any downstream mods that use IProvideTooltipInfo on enemy actors
+				if (frozen.Actor != null)
+					ActorTooltipExtra = frozen.Actor.TraitsImplementing<IProvideTooltipInfo>().ToArray();
 
-					// HACK: This leaks the tooltip state through the fog
-					// This will cause issues for any downstream mods that use IProvideTooltipInfo on enemy actors
-					if (frozen.Actor != null)
-						ActorTooltipExtra = frozen.Actor.TraitsImplementing<IProvideTooltipInfo>().ToArray();
-
-					TooltipType = WorldTooltipType.FrozenActor;
-					return;
-				}
+				TooltipType = WorldTooltipType.FrozenActor;
+				return;
 			}
 
 			if (resourceLayer != null)