From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Sun, 3 May 2020 14:25:55 -0400
Subject: [PATCH] Sync position on teleportation

We've seen many a cases where the "last good" x/y/z is desynced from
the x/y/z that is checked for moving too fast.

Theory is that when you have multiple movement packets queued up,
and the player is teleported after the first then the 2nd and 3rd come in,
it is triggering a massive movement velocity.

This will ensure that the servers position is synchronized anytime player is teleported.

diff --git a/src/main/java/net/minecraft/server/PlayerConnection.java b/src/main/java/net/minecraft/server/PlayerConnection.java
index 93536306c39c1ee574d45f39e8e40df3540c6e51..681de2638eb606185077668d87340f7258e2ad90 100644
--- a/src/main/java/net/minecraft/server/PlayerConnection.java
+++ b/src/main/java/net/minecraft/server/PlayerConnection.java
@@ -501,6 +501,7 @@ public class PlayerConnection implements PacketListenerPlayIn {
             this.o = this.teleportPos.x;
             this.p = this.teleportPos.y;
             this.q = this.teleportPos.z;
+            this.syncPosition(); // Paper
             if (this.player.H()) {
                 this.player.I();
             }
@@ -1300,6 +1301,7 @@ public class PlayerConnection implements PacketListenerPlayIn {
 
         this.A = this.e;
         this.player.setLocation(d0, d1, d2, f, f1);
+        this.syncPosition(); // Paper
         this.player.playerConnection.sendPacket(new PacketPlayOutPosition(d0 - d3, d1 - d4, d2 - d5, f - f2, f1 - f3, set, this.teleportAwait));
     }