disallow removing any node using the igniter

moremesecons_igniter/init.lua

@@ -1,12 +1,36 @@
+local function add_back_igniter(pos)
+	local name = minetest.get_node(pos).name
+
+	if name == "moremesecons_igniter:igniter" then
+		-- this should not happen
+		minetest.log("error", "[moremesecons_igniter] igniter is already back")
+		return
+	end
+
+	if name == "ignore" then
+		-- in case of unloaded chunk
+		minetest.get_voxel_manip():read_from_map(pos, pos)
+		name = minetest.get_node(pos).name
+	end
+
+	if name == "air"
+	or name == "fire:basic_flame" then
+		minetest.set_node(pos, {name="moremesecons_igniter:igniter"})
+	else
+		-- drop it as item if something took place there in the 0.8 seconds
+		pos.y = pos.y+1
+		minetest.add_item(pos, "moremesecons_igniter:igniter")
+		pos.y = pos.y-1
+	end
+end
+
 local function igniter_on(pos)
-	local fire_node = {name="fire:basic_flame"}
-	local igniter_node = {name="moremesecons_igniter:igniter"}
-	minetest.set_node(pos, fire_node)
-	minetest.after(0.8, minetest.set_node, pos, igniter_node)
+	minetest.set_node(pos, {name="fire:basic_flame"})
+	minetest.after(0.8, add_back_igniter, pos)
 end
 
 minetest.register_node("moremesecons_igniter:igniter", {
-	description="Igniter",
+	description = "Igniter",
 	paramtype = "light",
 	tiles = {"moremesecons_igniter.png"},
 	groups = {cracky=3},