From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Shane Freeder <theboyetronic@gmail.com>
Date: Tue, 22 Jun 2021 19:32:19 +0100
Subject: [PATCH] Fix kick event being fired off main thread


diff --git a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
index 0c295854f31422cf3ad699d229805c5881a65eed..c4fcab527c35eee94f88c7e499b9d2959d704808 100644
--- a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
+++ b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
@@ -108,6 +108,7 @@ import net.minecraft.network.protocol.game.ServerboundTeleportToEntityPacket;
 import net.minecraft.network.protocol.game.ServerboundUseItemOnPacket;
 import net.minecraft.network.protocol.game.ServerboundUseItemPacket;
 import net.minecraft.resources.ResourceLocation;
+import net.minecraft.server.MCUtil;
 import net.minecraft.server.MinecraftServer;
 import net.minecraft.server.level.ServerLevel;
 import net.minecraft.server.level.ServerPlayer;
@@ -440,11 +441,16 @@ public class ServerGamePacketListenerImpl implements ServerPlayerConnection, Ser
         }
         net.kyori.adventure.text.Component leaveMessage = net.kyori.adventure.text.Component.translatable("multiplayer.player.left", net.kyori.adventure.text.format.NamedTextColor.YELLOW, this.player.getBukkitEntity().displayName()); // Paper - Adventure
 
-        PlayerKickEvent event = new PlayerKickEvent(this.player.getBukkitEntity(), reason, leaveMessage, cause); // Paper - Adventure & kick event reason
+        // Paper start - ensire kick event is fired on main
+        final PlayerKickEvent event = MCUtil.ensureMain(() -> {
+        PlayerKickEvent playerKickEvent = new PlayerKickEvent(this.player.getBukkitEntity(), reason, leaveMessage, cause); // Paper - Adventure & kick event reason
 
         if (this.cserver.getServer().isRunning()) {
-            this.cserver.getPluginManager().callEvent(event);
+            this.cserver.getPluginManager().callEvent(playerKickEvent);
         }
+        return playerKickEvent;
+        });
+        // Paper end
 
         if (event.isCancelled()) {
             // Do not kick the player