Fix bukkit connectivity issue.

fml/patches/minecraft/net/minecraft/client/network/NetHandlerPlayClient.java.patch

@@ -0,0 +1,18 @@
+--- ../src-base/minecraft/net/minecraft/client/network/NetHandlerPlayClient.java
++++ ../src-work/minecraft/net/minecraft/client/network/NetHandlerPlayClient.java
+@@ -1,6 +1,7 @@
+ package net.minecraft.client.network;
+ 
+ import com.google.common.base.Charsets;
++import cpw.mods.fml.client.FMLClientHandler;
+ import cpw.mods.fml.relauncher.Side;
+ import cpw.mods.fml.relauncher.SideOnly;
+ import io.netty.buffer.ByteBuf;
+@@ -215,6 +216,7 @@
+         this.field_147299_f = p_i45061_1_;
+         this.field_147307_j = p_i45061_2_;
+         this.field_147302_e = p_i45061_3_;
++        FMLClientHandler.instance().setPlayClient(this);
+     }
+ 
+     public void func_147296_c()

fml/src/main/java/cpw/mods/fml/client/FMLClientHandler.java

@@ -32,6 +32,7 @@ import net.minecraft.client.gui.ServerListEntryNormal;
 import net.minecraft.client.multiplayer.GuiConnecting;
 import net.minecraft.client.multiplayer.ServerData;
 import net.minecraft.client.multiplayer.WorldClient;
+import net.minecraft.client.network.NetHandlerPlayClient;
 import net.minecraft.client.network.OldServerPinger;
 import net.minecraft.client.renderer.entity.Render;
 import net.minecraft.client.renderer.entity.RenderManager;
@@ -684,5 +685,28 @@ public class FMLClientHandler implements IFMLSidedHandler
         {
             showGuiScreen(new GuiConnecting(guiMultiplayer, client, serverEntry));
         }
+        playClientBlock = new CountDownLatch(1);
+    }
+
+    private CountDownLatch playClientBlock;
+    public void setPlayClient(NetHandlerPlayClient netHandlerPlayClient)
+    {
+        playClientBlock.countDown();
+    }
+
+    @Override
+    public void waitForPlayClient()
+    {
+        boolean gotIt = false;
+        try
+        {
+            gotIt = playClientBlock.await(1,TimeUnit.SECONDS);
+        } catch (InterruptedException e)
+        {
+        }
+        if (!gotIt)
+        {
+            throw new RuntimeException("Timeout waiting for client thread to catch up!");
+        }
     }
 }

fml/src/main/java/cpw/mods/fml/common/FMLCommonHandler.java

@@ -498,4 +498,9 @@ public class FMLCommonHandler
     {
         return sidedDelegate.getClientPlayHandler();
     }
+
+    public void waitForPlayClient()
+    {
+        sidedDelegate.waitForPlayClient();
+    }
 }

fml/src/main/java/cpw/mods/fml/common/IFMLSidedHandler.java

@@ -48,4 +48,6 @@ public interface IFMLSidedHandler
     NetworkManager getClientToServerNetworkManager();
 
     INetHandler getClientPlayHandler();
+
+    void waitForPlayClient();
 }

fml/src/main/java/cpw/mods/fml/common/network/handshake/NetworkDispatcher.java

@@ -148,6 +148,7 @@ public class NetworkDispatcher extends SimpleChannelInboundHandler<Packet> imple
     void clientListenForServerHandshake()
     {
         manager.func_150723_a(EnumConnectionState.PLAY);
+        FMLCommonHandler.instance().waitForPlayClient();
         this.netHandler = FMLCommonHandler.instance().getClientPlayHandler();
         this.state = ConnectionState.AWAITING_HANDSHAKE;
     }

fml/src/main/java/cpw/mods/fml/server/FMLServerHandler.java

@@ -221,4 +221,9 @@ public class FMLServerHandler implements IFMLSidedHandler
     {
         return null;
     }
+    @Override
+    public void waitForPlayClient()
+    {
+        // NOOP
+    }
 }