Restrict vanilla teleport command to within worldborder

Fixes GH-3165

Spigot-Server-Patches/0480-Restrict-vanilla-teleport-command-to-worldborder.patch

@@ -0,0 +1,25 @@
+From b05693d1f838ea0610b915f48954530dca2943ff Mon Sep 17 00:00:00 2001
+From: Zach Brown <zach@zachbr.io>
+Date: Thu, 16 Apr 2020 20:07:29 -0500
+Subject: [PATCH] Restrict vanilla teleport command to worldborder
+
+
+diff --git a/src/main/java/net/minecraft/server/CommandTeleport.java b/src/main/java/net/minecraft/server/CommandTeleport.java
+index 3060b4f68..df2711978 100644
+--- a/src/main/java/net/minecraft/server/CommandTeleport.java
++++ b/src/main/java/net/minecraft/server/CommandTeleport.java
+@@ -116,6 +116,11 @@ public class CommandTeleport {
+     }
+ 
+     private static void a(CommandListenerWrapper commandlistenerwrapper, Entity entity, WorldServer worldserver, double d0, double d1, double d2, Set<PacketPlayOutPosition.EnumPlayerTeleportFlags> set, float f, float f1, @Nullable CommandTeleport.a commandteleport_a) {
++        // Paper start - Don't allow teleport command to go outside the world border
++        if (!worldserver.getWorldBorder().isInBounds(new BlockPosition(d0, d1, d2))) {
++            return;
++        }
++        // Paper end
+         if (entity instanceof EntityPlayer) {
+             ChunkCoordIntPair chunkcoordintpair = new ChunkCoordIntPair(new BlockPosition(d0, d1, d2));
+ 
+-- 
+2.26.1.windows.1
+