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 9b13be3be5c911a00f2278f05557795cd916054d..dde0e9f1911d34791c7d7396f82cff5f82eec253 100644
--- a/src/main/java/net/minecraft/server/EntityPlayer.java
+++ b/src/main/java/net/minecraft/server/EntityPlayer.java
@@ -122,7 +122,7 @@ 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
@@ -173,6 +173,7 @@ 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();
 
@@ -350,7 +351,7 @@ 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 bf14839c99a2c2336bba4a12ee49d4c7c79c30c9..c11e941ba1ab12507ca5acbcaf034a6dfd97bbca 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";