Paper/Spigot-Server-Patches/0431-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 cfccab0b33dfa387fdab09ad51d518d42b1b5775..950a16e8aafe71b54b4ba46b61b5d71f8aa3cf94 100644
--- a/src/main/java/net/minecraft/server/EntityPlayer.java
+++ b/src/main/java/net/minecraft/server/EntityPlayer.java
@@ -125,7 +125,7 @@ public class EntityPlayer extends EntityHuman implements ICrafting {
         this.serverStatisticManager = minecraftserver.getPlayerList().getStatisticManager(this);
         this.advancementDataPlayer = minecraftserver.getPlayerList().f(this);
         this.G = 1.0F;
-        this.c(worldserver);
+        //this.c(worldserver); // Paper - don't move to spawn on login, only first join
         this.co = minecraftserver.a(this);
 
         this.cachedSingleHashSet = new com.destroystokyo.paper.util.misc.PooledLinkedHashSets.PooledObjectLinkedOpenHashSet<>(this); // Paper
@@ -177,6 +177,7 @@ public class EntityPlayer extends EntityHuman implements ICrafting {
     }
     // CraftBukkit end
 
+    public final void moveToSpawn(WorldServer worldserver) { c(worldserver); } // Paper - OBFHELPER
     private void c(WorldServer worldserver) {
         BlockPosition blockposition = worldserver.getSpawn();
 
@@ -354,7 +355,7 @@ 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 c52c6cc6ab0bed4fbd088f6d32455e1a58a70c16..ce097978a072dd5499169277aa1143be97c3b4e1 100644
--- a/src/main/java/net/minecraft/server/PlayerList.java
+++ b/src/main/java/net/minecraft/server/PlayerList.java
@@ -136,6 +136,8 @@ 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";