papermc/Spigot-Server-Patches/0461-Don-t-move-existing-players-to-world-spawn.patch

From 3761e0c1541d0ec88c01ac318204538ee4c43315 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.

diff --git a/src/main/java/net/minecraft/server/EntityPlayer.java b/src/main/java/net/minecraft/server/EntityPlayer.java
index a16a8c10a2..50886c1374 100644
--- a/src/main/java/net/minecraft/server/EntityPlayer.java
+++ b/src/main/java/net/minecraft/server/EntityPlayer.java
@@ -118,7 +118,7 @@ public class EntityPlayer extends EntityHuman implements ICrafting {
         this.serverStatisticManager = minecraftserver.getPlayerList().getStatisticManager(this);
         this.advancementDataPlayer = minecraftserver.getPlayerList().f(this);
         this.H = 1.0F;
-        this.a(worldserver);
+        //this.a(worldserver); // Paper - don't move to spawn on login, only first join
 
         this.cachedSingleHashSet = new com.destroystokyo.paper.util.misc.PooledLinkedHashSets.PooledObjectLinkedOpenHashSet<>(this); // Paper
 
@@ -166,6 +166,7 @@ public class EntityPlayer extends EntityHuman implements ICrafting {
     }
     // CraftBukkit end
 
+    public void moveToSpawn(WorldServer worldserver) { a(worldserver); } // Paper - OBFHELPER
     private void a(WorldServer worldserver) {
         BlockPosition blockposition = worldserver.getSpawn();
 
@@ -306,7 +307,7 @@ public class EntityPlayer extends EntityHuman implements ICrafting {
                 position = new Vec3D(world.getSpawn());
             }
             this.world = world;
-            this.setPosition(position.getX(), position.getY(), position.getZ());
+            this.setPositionRaw(position.getX(), position.getY(), position.getZ()); // Paper - don't register to chunks yet
         }
         this.dimension = ((WorldServer) this.world).getWorldProvider().getDimensionManager();
         this.playerInteractManager.a((WorldServer) world);
diff --git a/src/main/java/net/minecraft/server/PlayerList.java b/src/main/java/net/minecraft/server/PlayerList.java
index 01345a62b7..dfe6251576 100644
--- a/src/main/java/net/minecraft/server/PlayerList.java
+++ b/src/main/java/net/minecraft/server/PlayerList.java
@@ -108,6 +108,7 @@ public abstract class PlayerList {
             NBTTagCompound bukkit = nbttagcompound.getCompound("bukkit");
             s = bukkit.hasKeyOfType("lastKnownName", 8) ? bukkit.getString("lastKnownName") : s;
         }
+        if (nbttagcompound == null) entityplayer.moveToSpawn(worldserver); // Paper - only move to spawn on first login, otherwise, stay where you are....
         // CraftBukkit end
 
         entityplayer.spawnIn(worldserver);
-- 
2.26.2