From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Sudzzy <originmc@outlook.com>
Date: Thu, 3 Mar 2016 02:50:31 -0600
Subject: [PATCH] Configurable inter-world teleportation safety

People are able to abuse the way Bukkit handles teleportation across worlds since it provides a built in teleportation
safety check.

To abuse the safety check, players are required to get into a location deemed unsafe by Bukkit e.g. be within a chest
or door block. While they are in this block, they accept a teleport request from a player within a different world. Once
the player teleports, Minecraft will recursively search upwards for a safe location, this could eventually land within a
player's skybase.

Example setup to perform the glitch: http://puu.sh/ng3PC/cf072dcbdb.png
The wanted destination was on top of the emerald block however the player ended on top of the diamond block.
This only is the case if the player is teleporting between worlds.

diff --git a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
index 136dd30ae472a58845a2d8f399d2040faed09345..a58b0d10d73310587a05e40e072029ee258063e1 100644
--- a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
+++ b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
@@ -1171,7 +1171,7 @@ public class CraftPlayer extends CraftHumanEntity implements Player {
             entity.connection.teleport(to);
         } else {
             // The respawn reason should never be used if the passed location is non null.
-            this.server.getHandle().respawn(entity, toWorld, true, to, true, null);
+            this.server.getHandle().respawn(entity, toWorld, true, to, !toWorld.paperConfig().environment.disableTeleportationSuffocationCheck, null); // Paper
         }
         return true;
     }