From 2acccd72610d240c115c17a63fe1d0b8a068406a Mon Sep 17 00:00:00 2001
From: Pierre-Yves Rollo <dev@pyrollo.com>
Date: Fri, 2 Feb 2018 22:44:58 +0100
Subject: [PATCH] Fix ndef nill value in steles mod when technics not installed

---
 steles/nodes.lua | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/steles/nodes.lua b/steles/nodes.lua
index 4eff56f..d2fb504 100644
--- a/steles/nodes.lua
+++ b/steles/nodes.lua
@@ -26,11 +26,11 @@ display_lib.register_display_entity("steles:text")
 for i, material in ipairs(steles.materials) do
 
 	local ndef = minetest.registered_nodes[material]
-	local groups = table.copy(ndef.groups)
-	groups.display_lib_node = 1
 
 	if ndef then
+		local groups = table.copy(ndef.groups)
 		local parts = material:split(":")
+		groups.display_lib_node = 1
 
 		minetest.register_node("steles:"..parts[2].."_stele", {
 			description = steles.materials_desc[i],