Paper/patches/unapplied/server/0721-Fix-Entity-Position-Desync.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Owen1212055 <23108066+Owen1212055@users.noreply.github.com>
Date: Thu, 23 Dec 2021 23:59:12 -0500
Subject: [PATCH] Fix Entity Position Desync

If entities were teleported in the first tick it would not be send to the client.

This excludes hanging entities, as this fix caused problematic behavior due to them having their own
position field.

diff --git a/src/main/java/net/minecraft/server/level/ServerEntity.java b/src/main/java/net/minecraft/server/level/ServerEntity.java
index d2c2075fb0378fd7ec148281d37d886c77a78ce8..40949825392281c2f7c756007781c672ec24665d 100644
--- a/src/main/java/net/minecraft/server/level/ServerEntity.java
+++ b/src/main/java/net/minecraft/server/level/ServerEntity.java
@@ -171,7 +171,7 @@ public class ServerEntity {
                 boolean flag4 = false;
                 boolean flag5 = false;
 
-                if (this.tickCount > 0 || this.entity instanceof AbstractArrow) {
+                if (!(this.entity instanceof net.minecraft.world.entity.decoration.HangingEntity) || this.tickCount > 0 || this.entity instanceof AbstractArrow) { // Paper - Always update position to fix first-tick teleports
                     long k = this.positionCodec.encodeX(vec3d);
                     long l = this.positionCodec.encodeY(vec3d);
                     long i1 = this.positionCodec.encodeZ(vec3d);