From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Shane Freeder <theboyetronic@gmail.com>
Date: Thu, 5 Oct 2017 01:54:07 +0100
Subject: [PATCH] handle PacketPlayInKeepAlive async

In 1.12.2, Mojang moved the processing of PacketPlayInKeepAlive off the main
thread, while entirely correct for the server, this causes issues with
plugins which are expecting the PlayerQuitEvent on the main thread.

In order to counteract some bad behavior, we will post handling of the
disconnection to the main thread, but leave the actual processing of the packet
off the main thread.

also adding some additional logging in order to help work out what is causing
random disconnections for clients.

diff --git a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
index 049436f5cc373f6d076a62ae2b548b0154a43b78..6049c63b4f7abde0840738638d4bf19172a01200 100644
--- a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
+++ b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
@@ -2781,14 +2781,18 @@ public class ServerGamePacketListenerImpl implements ServerPlayerConnection, Ser
 
     @Override
     public void handleKeepAlive(ServerboundKeepAlivePacket packet) {
-        PacketUtils.ensureRunningOnSameThread(packet, this, this.player.getLevel()); // CraftBukkit
+        //PlayerConnectionUtils.ensureMainThread(packetplayinkeepalive, this, this.player.getWorldServer()); // CraftBukkit // Paper - This shouldn't be on the main thread
         if (this.keepAlivePending && packet.getId() == this.keepAliveChallenge) {
             int i = (int) (Util.getMillis() - this.keepAliveTime);
 
             this.player.latency = (this.player.latency * 3 + i) / 4;
             this.keepAlivePending = false;
         } else if (!this.isSingleplayerOwner()) {
+            // Paper start - This needs to be handled on the main thread for plugins
+            server.submit(() -> {
             this.disconnect(new TranslatableComponent("disconnect.timeout"));
+            });
+            // Paper end
         }
 
     }