Make bots first-class players.

- Bots have their own Clients, with unique ClientIDs
 - Hosts can set bot team/color in the lobby
 - Bots are kicked when switching to a smaller map without enough slots
 - Order validator assumes that only client 0 has permission to issue bot orders

OpenRA.Game/Network/Session.cs

@@ -34,8 +34,7 @@ namespace OpenRA.Network
 
 		public string FirstEmptySlot()
 		{
-			return Slots.FirstOrDefault(s => !s.Value.Closed && ClientInSlot(s.Key) == null
-			                            && s.Value.Bot == null).Key;
+			return Slots.FirstOrDefault(s => !s.Value.Closed && ClientInSlot(s.Key) == null).Key;
 		}
 
 		public enum ClientState
@@ -55,12 +54,12 @@ namespace OpenRA.Network
 			public ClientState State;
 			public int Team;
 			public string Slot;	// slot ID, or null for observer
+			public string Bot; // Bot type, null for real clients
 		}
 
 		public class Slot
 		{
 			public string PlayerReference;	// playerReference to bind against.
-			public string Bot;	// trait name of the bot to initialize in this slot, or null otherwise.
 			public bool Closed;	// host has explicitly closed this slot.
 
 			public bool AllowBots;

OpenRA.Game/Network/UnitOrders.cs

@@ -21,10 +21,9 @@ namespace OpenRA.Network
 		static Player FindPlayerByClient(this World world, Session.Client c)
 		{
 			/* todo: this is still a hack. 
-			 * the cases we're trying to avoid are the extra players on the host's client -- Neutral, other MapPlayers,
-			 * bots,.. */
+			 * the cases we're trying to avoid are the extra players on the host's client -- Neutral, other MapPlayers,..*/
 			return world.Players.FirstOrDefault(
-				p => (p.ClientIndex == c.Index && p.PlayerRef.Playable && !p.IsBot));
+				p => (p.ClientIndex == c.Index && p.PlayerRef.Playable));
 		}
 
 		public static void ProcessOrder(OrderManager orderManager, World world, int clientId, Order order)

OpenRA.Game/Player.cs

@@ -46,11 +46,13 @@ namespace OpenRA
 			PlayerRef = pr;
 			string botType = null;
 			
+			// Real player or host-created bot
 			if (client != null)
 			{
 				ClientIndex = client.Index;
             	ColorRamp = client.ColorRamp;
 				PlayerName = client.Name;
+				botType = client.Bot;
 
 				Country = world.GetCountries()
 					.FirstOrDefault(c => client.Country == c.Race)
@@ -58,36 +60,21 @@ namespace OpenRA
 			}
 			else
 			{
-				// Map player or bot
+				// Map player
 				ClientIndex = 0; 		/* it's a map player, "owned" by host */
 				ColorRamp = pr.ColorRamp;
 				PlayerName = pr.Name;
 				NonCombatant = pr.NonCombatant;
-				IsBot = pr.Bot != null;
 				botType = pr.Bot;
 
 				Country = world.GetCountries()
 					.FirstOrDefault(c => pr.Race == c.Race)
 					?? world.GetCountries().Random(world.SharedRandom);
-
-				// Multiplayer bot
-				if (slot != null && slot.Bot != null)
-				{
-					IsBot = true;
-					botType = slot.Bot;
-					PlayerName = slot.Bot;
-
-					// pick a random color for the bot
-					var hue = (byte)world.SharedRandom.Next(255);
-					var sat = (byte)world.SharedRandom.Next(255);
-					var lum = (byte)world.SharedRandom.Next(51,255);
-					ColorRamp = new ColorRamp(hue, sat, lum, 10);
-				}
 			}
-			
 			PlayerActor = world.CreateActor("Player", new TypeDictionary { new OwnerInit(this) });
 
-			// Enable the bot logic
+			// Enable the bot logic on the host
+			IsBot = botType != null;
 			if (IsBot && Game.IsHost)
 			{
 				var logic = PlayerActor.TraitsImplementing<IBot>()

OpenRA.Game/Server/Server.cs

@@ -129,10 +129,11 @@ namespace OpenRA.Server
 		 *		for manual spawnpoint choosing.
 		 *	- 256 max players is a dirty hack
 		 */
-		int ChooseFreePlayerIndex()
+		public int ChooseFreePlayerIndex()
 		{
 			for (var i = 0; i < 256; i++)
-				if (conns.All(c => c.PlayerIndex != i) && preConns.All(c => c.PlayerIndex != i))
+				if (conns.All(c => c.PlayerIndex != i) && preConns.All(c => c.PlayerIndex != i)
+				    && lobbyInfo.Clients.All(c => c.Index != i))
 					return i;
 
 			throw new InvalidOperationException("Already got 256 players");

OpenRA.Game/Traits/ValidateOrder.cs

@@ -18,10 +18,18 @@ namespace OpenRA.Traits
     {
         public bool OrderValidation(OrderManager orderManager, World world, int clientId, Order order)
         {            
-            // Drop exploiting orders
-            if (order.Subject != null && order.Subject.Owner.ClientIndex != clientId)
+			if (order.Subject == null || order.Subject.Owner == null)
+				return true;
+
+			var subjectClient = order.Subject.Owner.ClientIndex;
+
+			// Hack: Assumes bots always run on clientId 0.
+			var isBotOrder = orderManager.LobbyInfo.Clients[subjectClient].Bot != null && clientId == 0;
+
+			// Drop exploiting orders
+			if (subjectClient != clientId && !isBotOrder)
             {
-                Game.Debug("Detected exploit order from {0}: {1}".F(clientId, order.OrderString));
+                Game.Debug("Detected exploit order from client {0}: {1}".F(clientId, order.OrderString));
                 return false;
             }