From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Denery <dorofeevij@gmail.com>
Date: Sun, 6 Nov 2022 02:02:46 +0300
Subject: [PATCH] Fix player kick on shutdown

Fix preemptive player kick on a server shutdown.
If you update minecraft version / upstream and something is changed in this method make sure that a server doesn't disconnect a player preemptively,
also check if all packets are ignored during the shutdown process.
See net.minecraft.network.Connection#channelRead0(ChannelHandlerContext, Packet) and net.minecraft.util.thread.BlockableEventLoop#executeIfPossible(Runnable)

diff --git a/src/main/java/net/minecraft/network/protocol/PacketUtils.java b/src/main/java/net/minecraft/network/protocol/PacketUtils.java
index b7ffab0284b0bccd79775b8d03c8b2e088f91d1d..4202c48ad8f8e85ef46d1bd446ab28f3f4b083d1 100644
--- a/src/main/java/net/minecraft/network/protocol/PacketUtils.java
+++ b/src/main/java/net/minecraft/network/protocol/PacketUtils.java
@@ -26,7 +26,7 @@ public class PacketUtils {
 
     public static <T extends PacketListener> void ensureRunningOnSameThread(Packet<T> packet, T listener, BlockableEventLoop<?> engine) throws RunningOnDifferentThreadException {
         if (!engine.isSameThread()) {
-            engine.executeIfPossible(() -> {
+            engine.execute(() -> { // Paper - Fix preemptive player kick on a server shutdown
                 if (listener instanceof ServerCommonPacketListenerImpl serverCommonPacketListener && serverCommonPacketListener.processedDisconnect) return; // CraftBukkit - Don't handle sync packets for kicked players
                 if (listener.shouldHandleMessage(packet)) {
                     co.aikar.timings.Timing timing = co.aikar.timings.MinecraftTimings.getPacketTiming(packet); // Paper - timings