From bb23022f8a18e30fb96036e8c6c7517af3ae42d6 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Sun, 19 Apr 2020 04:28:29 -0400
Subject: [PATCH] Load Chunks for Login Asynchronously


diff --git a/src/main/java/net/minecraft/server/Entity.java b/src/main/java/net/minecraft/server/Entity.java
index 96a47dd1c2..96ebe0b226 100644
--- a/src/main/java/net/minecraft/server/Entity.java
+++ b/src/main/java/net/minecraft/server/Entity.java
@@ -1382,7 +1382,7 @@ public abstract class Entity implements INamableTileEntity, ICommandListener, Ke
         this.pitch = MathHelper.a(f1, -90.0F, 90.0F) % 360.0F;
         this.lastYaw = this.yaw;
         this.lastPitch = this.pitch;
-        world.getChunkAt((int) Math.floor(this.locX) >> 4, (int) Math.floor(this.locZ) >> 4); // CraftBukkit
+        if (valid) world.getChunkAt((int) Math.floor(this.locX) >> 4, (int) Math.floor(this.locZ) >> 4); // CraftBukkit // Paper
     }
 
     public void setPositionRotation(BlockPosition blockposition, float f, float f1) {
diff --git a/src/main/java/net/minecraft/server/PlayerConnection.java b/src/main/java/net/minecraft/server/PlayerConnection.java
index 7929fcc800..c3710b73af 100644
--- a/src/main/java/net/minecraft/server/PlayerConnection.java
+++ b/src/main/java/net/minecraft/server/PlayerConnection.java
@@ -142,6 +142,7 @@ public class PlayerConnection implements PacketListenerPlayIn {
     // CraftBukkit end
 
     public void tick() {
+        if (!this.player.valid) return; // Paper
         this.syncPosition();
         this.player.lastX = this.player.locX();
         this.player.lastY = this.player.locY();
diff --git a/src/main/java/net/minecraft/server/PlayerList.java b/src/main/java/net/minecraft/server/PlayerList.java
index ec45c30dd3..de55423686 100644
--- a/src/main/java/net/minecraft/server/PlayerList.java
+++ b/src/main/java/net/minecraft/server/PlayerList.java
@@ -173,6 +173,17 @@ public abstract class PlayerList {
         this.players.add(entityplayer);
         this.playersByName.put(entityplayer.getName().toLowerCase(java.util.Locale.ROOT), entityplayer); // Spigot
         this.j.put(entityplayer.getUniqueID(), entityplayer);
+        // Paper start - async load spawn in chunk
+        WorldServer finalWorldserver = worldserver;
+        worldserver.getChunkProvider().getTickingChunkAsync(loc.getBlockX() >> 4, loc.getBlockZ() >> 4, (chunk -> { // use ticking - as it has at least 1 neighbours loaded
+            postChunkLoadJoin(entityplayer, finalWorldserver, playerconnection, nbttagcompound, networkmanager.getSocketAddress().toString(), joinMessage);
+        }));
+    }
+    private void postChunkLoadJoin(EntityPlayer entityplayer, WorldServer worldserver, PlayerConnection playerconnection, NBTTagCompound nbttagcompound, String s1, String joinMessage) {
+        if (!entityplayer.playerConnection.networkManager.isConnected()) {
+            return;
+        }
+        // Paper end
         // this.sendAll(new PacketPlayOutPlayerInfo(PacketPlayOutPlayerInfo.EnumPlayerInfoAction.ADD_PLAYER, new EntityPlayer[]{entityplayer})); // CraftBukkit - replaced with loop below
 
         // Paper start - correctly register player BEFORE PlayerJoinEvent, so the entity is valid and doesn't require tick delay hacks
-- 
2.25.1