papermc/Spigot-Server-Patches/0441-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.

diff --git a/src/main/java/net/minecraft/server/EntityPlayer.java b/src/main/java/net/minecraft/server/EntityPlayer.java
index 52b5c47452a46cd6e61e1dd7c135620e36472c73..62f6e507586560355269b54a6c3921296106a3bc 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.G = 1.0F;
-        this.b(worldserver);
+        //this.b(worldserver); // Paper - don't move to spawn on login, only first join
 
         this.cachedSingleHashSet = new com.destroystokyo.paper.util.misc.PooledLinkedHashSets.PooledObjectLinkedOpenHashSet<>(this); // Paper
 
@@ -171,6 +171,7 @@ public class EntityPlayer extends EntityHuman implements ICrafting {
     }
     // CraftBukkit end
 
+    public final void moveToSpawn(WorldServer worldserver) { b(worldserver); } // Paper - OBFHELPER
     private void b(WorldServer worldserver) {
         BlockPosition blockposition = worldserver.getSpawn();
 
@@ -346,7 +347,7 @@ public class EntityPlayer extends EntityHuman implements ICrafting {
                 position = Vec3D.a(((WorldServer) 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.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 cac27c509dd3bec9f7feabf5804d1140055b1c6e..610c3ed31e0dceeded4dbd5f63db23def88e1ea6 100644
--- a/src/main/java/net/minecraft/server/PlayerList.java
+++ b/src/main/java/net/minecraft/server/PlayerList.java
@@ -134,6 +134,8 @@ public abstract class PlayerList {
             worldserver1 = worldserver;
         }
 
+        if (nbttagcompound == null) entityplayer.moveToSpawn(worldserver1); // Paper - only move to spawn on first login, otherwise, stay where you are....
+
         entityplayer.spawnIn(worldserver1);
         entityplayer.playerInteractManager.a((WorldServer) entityplayer.world);
         String s1 = "local";