PaperMC/Remapped-Spigot-Server-Patches/0054-Configurable-inter-world-teleportation-safety.patch

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 670efbe53241a0ae32d618c83da601ccc1f26e37..abbbe1786eb68af02f9d39650aad730ac44aac8a 100644
--- a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
+++ b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
@@ -205,4 +205,9 @@ public class PaperWorldConfig {
         portalCreateRadius = getInt("portal-create-radius", 16);
         portalSearchVanillaDimensionScaling = getBoolean("portal-search-vanilla-dimension-scaling", true);
     }
+
+    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 63933bd455ad72a772d4db160e946600b84a1791..3b9d61b524441f65646edf7d403b6c5b5345b1e5 100644
--- a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
+++ b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
@@ -861,7 +861,7 @@ public class CraftPlayer extends CraftHumanEntity implements Player {
         if (fromWorld == toWorld) {
             entity.connection.teleport(to);
         } else {
-            server.getHandle().moveToWorld(entity, toWorld, true, to, true);
+            server.getHandle().moveToWorld(entity, toWorld, true, to, !toWorld.paperConfig.disableTeleportationSuffocationCheck); // Paper
         }
         return true;
     }