Check item registered before getting group/drawtype

~ Minor update to check node is registered before trying to retrieve groups or drawtype

init.lua

@@ -179,8 +179,14 @@ minetest.register_globalstep(function()
 -- stop standing under slabs --
 -------------------------------	                                          -- Whole section WIP needs cleanup			
 		local ch = minetest.get_node({x=pos.x,y=pos.y+1,z=pos.z})
-		local ch_g = minetest.registered_nodes[ch.name].groups
-		local ch_d = minetest.registered_nodes[ch.name].drawtype
+		local ch_g = {}
+		local ch_d = "normal"
+		
+		if minetest.registered_nodes[ch.name] then
+			local ch_g = minetest.registered_nodes[ch.name].groups
+			local ch_d = minetest.registered_nodes[ch.name].drawtype
+		end
+		
 		local ch_slab = 0
 		local ch_node = 0
 		for k,v in pairs(ch_g) do