CatServer/patches/net/minecraft/network/NetworkSystem.java.patch

--- ../src-base/minecraft/net/minecraft/network/NetworkSystem.java
+++ ../src-work/minecraft/net/minecraft/network/NetworkSystem.java
@@ -49,21 +49,21 @@
     {
         protected NioEventLoopGroup load()
         {
-            return new NioEventLoopGroup(0, (new ThreadFactoryBuilder()).setNameFormat("Netty Server IO #%d").setDaemon(true).build());
+            return new NioEventLoopGroup(0, (new ThreadFactoryBuilder()).setNameFormat("Netty Server IO #%d").setDaemon(true).setThreadFactory(net.minecraftforge.fml.common.thread.SidedThreadGroups.SERVER).build());
         }
     };
     public static final LazyLoadBase<EpollEventLoopGroup> SERVER_EPOLL_EVENTLOOP = new LazyLoadBase<EpollEventLoopGroup>()
     {
         protected EpollEventLoopGroup load()
         {
-            return new EpollEventLoopGroup(0, (new ThreadFactoryBuilder()).setNameFormat("Netty Epoll Server IO #%d").setDaemon(true).build());
+            return new EpollEventLoopGroup(0, (new ThreadFactoryBuilder()).setNameFormat("Netty Epoll Server IO #%d").setDaemon(true).setThreadFactory(net.minecraftforge.fml.common.thread.SidedThreadGroups.SERVER).build());
         }
     };
     public static final LazyLoadBase<LocalEventLoopGroup> SERVER_LOCAL_EVENTLOOP = new LazyLoadBase<LocalEventLoopGroup>()
     {
         protected LocalEventLoopGroup load()
         {
-            return new LocalEventLoopGroup(0, (new ThreadFactoryBuilder()).setNameFormat("Netty Local Server IO #%d").setDaemon(true).build());
+            return new LocalEventLoopGroup(0, (new ThreadFactoryBuilder()).setNameFormat("Netty Local Server IO #%d").setDaemon(true).setThreadFactory(net.minecraftforge.fml.common.thread.SidedThreadGroups.CLIENT).build());
         }
     };
     private final MinecraftServer mcServer;
@@ -79,6 +79,7 @@
 
     public void addLanEndpoint(InetAddress address, int port) throws IOException
     {
+        if (address instanceof java.net.Inet6Address) System.setProperty("java.net.preferIPv4Stack", "false");
         synchronized (this.endpoints)
         {
             Class <? extends ServerSocketChannel > oclass;
@@ -110,7 +111,7 @@
                         ;
                     }
 
-                    p_initChannel_1_.pipeline().addLast("timeout", new ReadTimeoutHandler(30)).addLast("legacy_query", new LegacyPingHandler(NetworkSystem.this)).addLast("splitter", new NettyVarint21FrameDecoder()).addLast("decoder", new NettyPacketDecoder(EnumPacketDirection.SERVERBOUND)).addLast("prepender", new NettyVarint21FrameEncoder()).addLast("encoder", new NettyPacketEncoder(EnumPacketDirection.CLIENTBOUND));
+                    p_initChannel_1_.pipeline().addLast("timeout", new ReadTimeoutHandler(net.minecraftforge.fml.common.network.internal.FMLNetworkHandler.READ_TIMEOUT)).addLast("legacy_query", new LegacyPingHandler(NetworkSystem.this)).addLast("splitter", new NettyVarint21FrameDecoder()).addLast("decoder", new NettyPacketDecoder(EnumPacketDirection.SERVERBOUND)).addLast("prepender", new NettyVarint21FrameEncoder()).addLast("encoder", new NettyPacketEncoder(EnumPacketDirection.CLIENTBOUND));
                     NetworkManager networkmanager = new NetworkManager(EnumPacketDirection.SERVERBOUND);
                     NetworkSystem.this.networkManagers.add(networkmanager);
                     p_initChannel_1_.pipeline().addLast("packet_handler", networkmanager);
@@ -164,6 +165,13 @@
     {
         synchronized (this.networkManagers)
         {
+            // Spigot Start
+            // This prevents players from 'gaming' the server, and strategically relogging to increase their position in the tick order
+            if (org.spigotmc.SpigotConfig.playerShuffle > 0 && MinecraftServer.currentTick % org.spigotmc.SpigotConfig.playerShuffle == 0)
+            {
+                Collections.shuffle(this.networkManagers);
+            }
+            // Spigot End
             Iterator<NetworkManager> iterator = this.networkManagers.iterator();
 
             while (iterator.hasNext())
@@ -208,6 +216,9 @@
                     }
                     else
                     {
+                        // Spigot Start - Fix a race condition where a NetworkManager could be unregistered just before connection.
+                        if (networkmanager.preparing) continue;
+                        // Spigot End
                         iterator.remove();
                         networkmanager.checkDisconnected();
                     }