From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Thu, 9 Apr 2020 21:20:33 -0400
Subject: [PATCH] Don't move existing players to world spawn

This can cause a nasty server lag the spawn chunks are not kept loaded
or they aren't finished loading yet, or if the world spawn radius is
larger than the keep loaded range.

By skipping this, we avoid potential for a large spike on server start.

== AT ==
public net.minecraft.server.level.ServerPlayer fudgeSpawnLocation(Lnet/minecraft/server/level/ServerLevel;)V

diff --git a/src/main/java/net/minecraft/server/level/ServerPlayer.java b/src/main/java/net/minecraft/server/level/ServerPlayer.java
index 9f3a7ba170b729fad228e212436f15bb8169f906..5437ccea0205c23435de3584b26ee5a48afc5d1b 100644
--- a/src/main/java/net/minecraft/server/level/ServerPlayer.java
+++ b/src/main/java/net/minecraft/server/level/ServerPlayer.java
@@ -419,7 +419,7 @@ public class ServerPlayer extends net.minecraft.world.entity.player.Player {
         this.server = server;
         this.stats = server.getPlayerList().getPlayerStats(this);
         this.advancements = server.getPlayerList().getPlayerAdvancements(this);
-        this.moveTo(this.adjustSpawnLocation(world, world.getSharedSpawnPos()).getBottomCenter(), 0.0F, 0.0F);
+        // this.moveTo(this.adjustSpawnLocation(world, world.getSharedSpawnPos()).getBottomCenter(), 0.0F, 0.0F); // Paper - Don't move existing players to world spawn
         this.updateOptions(clientOptions);
         this.object = null;
 
@@ -856,7 +856,7 @@ public class ServerPlayer extends net.minecraft.world.entity.player.Player {
                 position = Vec3.atCenterOf(world.getSharedSpawnPos());
             }
             this.setLevel(world);
-            this.setPos(position);
+            this.setPosRaw(position.x(), position.y(), position.z()); // Paper - don't register to chunks yet
         }
         this.gameMode.setLevel((ServerLevel) world);
     }
diff --git a/src/main/java/net/minecraft/server/players/PlayerList.java b/src/main/java/net/minecraft/server/players/PlayerList.java
index 2f48182fea64a82857cbb93dc94f7019ac55215a..e137278f9dc02eefaaf7071a3219436a94cfcfac 100644
--- a/src/main/java/net/minecraft/server/players/PlayerList.java
+++ b/src/main/java/net/minecraft/server/players/PlayerList.java
@@ -226,6 +226,7 @@ public abstract class PlayerList {
         // Paper start - Entity#getEntitySpawnReason
         if (optional.isEmpty()) {
             player.spawnReason = org.bukkit.event.entity.CreatureSpawnEvent.SpawnReason.DEFAULT; // set Player SpawnReason to DEFAULT on first login
+            player.moveTo(player.adjustSpawnLocation(worldserver1, worldserver1.getSharedSpawnPos()).getBottomCenter(), 0.0F, 0.0F);
         }
         // Paper end - Entity#getEntitySpawnReason
         player.setServerLevel(worldserver1);