From 69b3e65c851adc8f8e25ee3629fa94c1b6617f72 Mon Sep 17 00:00:00 2001
From: Hybrid Dog <ovvv@web.de>
Date: Tue, 26 Dec 2017 08:40:18 +0100
Subject: [PATCH] Fix missing unknown node test in grass_allowed

---
 nether/init.lua | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/nether/init.lua b/nether/init.lua
index 7ef7417..decc285 100644
--- a/nether/init.lua
+++ b/nether/init.lua
@@ -970,6 +970,10 @@ local function grass_allowed(pos)
 		return 0
 	end
 	local data = minetest.registered_nodes[nd]
+	if not data then
+		-- unknown node
+		return false
+	end
 	local drawtype = data.drawtype
 	if drawtype
 	and drawtype ~= "normal"