fixed issue where corrupted lobby server message can lead to null player be tracked by infra and then failing in !ring etc. fix #2998

Author: Licho1

Shared/LobbyClient/Spring.SpringBattleContext.cs

@@ -47,6 +47,8 @@ public class SpringBattleContext
 
         public BattlePlayerResult GetOrAddPlayer(string name)
         {
+            if (string.IsNullOrEmpty(name)) return null; // we don't want to add null players
+            
             var ret = ActualPlayers.FirstOrDefault(y => y.Name == name);
             if (ret == null)
             {

ZkLobbyServer/ServerBattle.cs

@@ -181,7 +181,7 @@ public List<string> GetAllUserNames()
         {
             var ret = Users.Select(x => x.Key).ToList();
             if (spring.IsRunning) ret.AddRange(spring.Context.ActualPlayers.Select(x => x.Name));
-            return ret.Distinct().ToList();
+            return ret.Distinct().Where(x=>x!=null).ToList();
         }
 
         public BattleCommand GetCommandByName(string name)

ZkLobbyServer/autohost/Commands/CmdKick.cs

@@ -90,7 +90,7 @@ private bool NotifyAdminChannel(ServerBattle battle, Say e, bool isActualKick)
                 {
                     gtype = string.Format("game on map {0}", battle.MapName);
                     PlasmaShared.BattlePlayerResult res = battle.spring.Context.GetOrAddPlayer(target);
-                    isspec = res.IsSpectator;
+                    isspec = res?.IsSpectator == true;
                 }
                 else
                 {