From dc8778d7d310fe8bcff778b8f768caa8a61a9f84 Mon Sep 17 00:00:00 2001
From: luk3yx <luk3yx@users.noreply.github.com>
Date: Wed, 16 Jan 2019 10:31:07 +1300
Subject: Fix crash when lua tubes are DoSed.

---
 lua_tube.lua | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/lua_tube.lua b/lua_tube.lua
index 941ef92..689f74e 100644
--- a/lua_tube.lua
+++ b/lua_tube.lua
@@ -333,8 +333,11 @@ local safe_globals = {
 }
 
 local function create_environment(pos, mem, event)
-	-- Gather variables for the environment
+	-- Make sure the tube hasn't broken.
 	local vports = minetest.registered_nodes[minetest.get_node(pos).name].virtual_portstates
+	if not vports then return {} end
+
+	-- Gather variables for the environment
 	local vports_copy = {}
 	for k, v in pairs(vports) do vports_copy[k] = v end
 	local rports = get_real_port_states(pos)
-- 
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