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/com/destroystokyo/paper/PaperWorldConfig.java b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
index cff769a0cffd81501f919fad0c6456e1268bd223..a6c02f676f4206f2f59862530999cd74a2e0c20f 100644
--- a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
+++ b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
@@ -199,4 +199,9 @@ public class PaperWorldConfig {
         portalSearchRadius = getInt("portal-search-radius", 128);
         portalCreateRadius = getInt("portal-create-radius", 16);
     }
+
+    public boolean disableTeleportationSuffocationCheck;
+    private void disableTeleportationSuffocationCheck() {
+        disableTeleportationSuffocationCheck = getBoolean("disable-teleportation-suffocation-check", false);
+    }
 }
diff --git a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
index 04a3700c6d4caffcf5b8f7867d12d42ac4478a37..a1e00c468e77bfa995f117207ad3208bdc7ec028 100644
--- a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
+++ b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
@@ -783,7 +783,7 @@ public class CraftPlayer extends CraftHumanEntity implements Player {
         if (fromWorld == toWorld) {
             entity.playerConnection.teleport(to);
         } else {
-            server.getHandle().moveToWorld(entity, toWorld, true, to, true);
+            server.getHandle().moveToWorld(entity, toWorld, true, to, !toWorld.paperConfig.disableTeleportationSuffocationCheck); // Paper
         }
         return true;
     }