Paper/patches/server/0346-Don-t-move-existing-players-to-world-spawn.patch

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 ca75d22e90fd879d464733813939f877ec875905..04e54d2214d0ae0202490aceab54b8b10ef38229 100644
--- a/src/main/java/net/minecraft/server/level/ServerPlayer.java
+++ b/src/main/java/net/minecraft/server/level/ServerPlayer.java
@@ -337,7 +337,7 @@ public class ServerPlayer extends Player {
         this.stats = server.getPlayerList().getPlayerStats(this);
         this.advancements = server.getPlayerList().getPlayerAdvancements(this);
         this.setMaxUpStep(1.0F);
-        this.fudgeSpawnLocation(world);
+        // this.fudgeSpawnLocation(world); // Paper - Don't move existing players to world spawn
         this.updateOptions(clientOptions);
 
         this.cachedSingleHashSet = new com.destroystokyo.paper.util.misc.PooledLinkedHashSets.PooledObjectLinkedOpenHashSet<>(this); // Paper
@@ -571,7 +571,7 @@ public class ServerPlayer extends 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 6bd83549e2ff84b1bc993ef2be79a336ced28f67..8f23597eee06e721a25f7be3a5a65dff6a59ee55 100644
--- a/src/main/java/net/minecraft/server/players/PlayerList.java
+++ b/src/main/java/net/minecraft/server/players/PlayerList.java
@@ -227,6 +227,7 @@ public abstract class PlayerList {
         // Paper start - Entity#getEntitySpawnReason
         if (nbttagcompound == null) {
             player.spawnReason = org.bukkit.event.entity.CreatureSpawnEvent.SpawnReason.DEFAULT; // set Player SpawnReason to DEFAULT on first login
+            player.fudgeSpawnLocation(worldserver1); // Paper - Don't move existing players to world spawn
         }
         // Paper end - Entity#getEntitySpawnReason
         player.setServerLevel(worldserver1);