papermc/Spigot-Server-Patches/0460-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 aa9c903aa82640658d648642a0ef426eb993a3d9..d51af68a92021e4f45631805529424831ca9b090 100644
--- a/src/main/java/net/minecraft/server/EntityPlayer.java
+++ b/src/main/java/net/minecraft/server/EntityPlayer.java
@@ -114,7 +114,7 @@ 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
 
@@ -162,6 +162,7 @@ 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();
 
@@ -302,7 +303,7 @@ 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 909d86e14c7860cd6d8a6f38ef4aedb183acae3f..0b5800649abfc2fd6722e4cb5e8e40e51240a032 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);