Extra error checking.

asteroids.lua

@@ -43,11 +43,17 @@ local plant_noise = {offset = 0.0, scale = 1.0, spread = {x = 200, y = 200, z =
 local biome_noise = {offset = 0.0, scale = 1.0, spread = {x = 400, y = 400, z = 400}, seed = -1471, octaves = 3, persist = 0.5, lacunarity = 2.0}
 
 fun_caves.asteroids = function(minp, maxp, data, p2data, area, node)
+	if not (minp and maxp and data and p2data and area and node and type(data) == 'table' and type(p2data) == 'table') then
+		return
+	end
+
 	if minp.y < 11168 or minp.y > 15168 then
 		return
 	end
 
-	math.randomseed(minetest.get_us_time())
+	-- What's this for?
+	--math.randomseed(minetest.get_us_time())
+
 	local density = 4 + math.abs(minp.y - 13168) / 500
 	local empty = false
 	if math.random(math.floor(density)) ~= 1 then
@@ -60,6 +66,9 @@ fun_caves.asteroids = function(minp, maxp, data, p2data, area, node)
 	local map_min = {x = minp.x, y = minp.y, z = minp.z}
 
 	local asteroid_1 = minetest.get_perlin_map(asteroid_noise_1, map_max):get3dMap_flat(map_min)
+	if not asteroid_1 then
+		return
+	end
 
 	local write = false
 

cavegen.lua

@@ -19,6 +19,10 @@ ground_nodes[minetest.get_content_id('default:dirt_with_dry_grass')] = true
 
 
 fun_caves.cavegen = function(minp, maxp, data, area, node, heightmap, underzone)
+	if not (minp and maxp and data and area and node and type(data) == 'table') then
+		return
+	end
+
 	local csize = vector.add(vector.subtract(maxp, minp), 1)
 	local map_max = {x = csize.x, y = csize.y + 2, z = csize.z}
 	local map_min = {x = minp.x, y = minp.y - 1, z = minp.z}
@@ -32,6 +36,9 @@ fun_caves.cavegen = function(minp, maxp, data, area, node, heightmap, underzone)
 	local cave_1 = minetest.get_perlin_map(fun_caves.cave_noise_1, map_max):get3dMap_flat(map_min)
 	local cave_2 = minetest.get_perlin_map(fun_caves.cave_noise_2, map_max):get3dMap_flat(map_min)
 	local cave_3 = minetest.get_perlin_map(cave_noise_3, {x=csize.x, y=csize.z}):get2dMap_flat({x=minp.x, y=minp.z})
+	if not (cave_1 and cave_2 and cave_3) then
+		return
+	end
 
 	local write = false
 

chat.lua

@@ -3,7 +3,15 @@ minetest.register_chatcommand("armor", {
 	description = "Display your armor values",
 	privs = {},
 	func = function(player_name, param)
+		if not (player_name and type(player_name) == 'string' and player_name ~= '') then
+			return
+		end
+
 		local player = minetest.get_player_by_name(player_name)
+		if not player then
+			return
+		end
+
 		local armor = player:get_armor_groups()
 		if armor then
 			minetest.chat_send_player(player_name, "Armor:")
@@ -13,7 +21,12 @@ minetest.register_chatcommand("armor", {
 
 			if fun_caves.db.status[player_name].armor_elixir then
 				local armor_time = fun_caves.db.status[player_name].armor_elixir.remove
-				local min = math.floor(math.max(0, armor_time - minetest.get_gametime()) / 60)
+				local game_time = minetest.get_gametime()
+				if not (armor_time and type(armor_time) == 'number' and game_time and type(game_time) == 'number') then
+					return
+				end
+
+				local min = math.floor(math.max(0, armor_time - game_time) / 60)
 				minetest.chat_send_player(player_name, "Your armor elixir will expire in "..min..' minutes.')
 			end
 		end
@@ -25,11 +38,19 @@ minetest.register_chatcommand("setspawn", {
 	params = "",
 	description = "change your spawn position",
 	privs = {},
-	func = function(name, param)
+	func = function(player_name, param)
-		local player = minetest.get_player_by_name(name)
+		if not (player_name and type(player_name) == 'string' and player_name ~= '') then
+			return
+		end
+
+		local player = minetest.get_player_by_name(player_name)
+		if not player then
+			return
+		end
+
 		local pos = player:getpos()
-		beds.spawn[name] = pos
+		beds.spawn[player_name] = pos
-		minetest.chat_send_player(name, 'Your spawn position has been changed.')
+		minetest.chat_send_player(player_name, 'Your spawn position has been changed.')
 	end,
 })
 
@@ -38,21 +59,38 @@ minetest.register_chatcommand("fixlight", {
 	params = "<radius>",
 	description = "attempt to fix light bugs",
 	privs = {},
-	func = function(name, param)
+	func = function(player_name, param)
-		local privs = minetest.check_player_privs(name, {server=true})
+		if not (player_name and type(player_name) == 'string' and player_name ~= '') then
+			return
+		end
+
+		local privs = minetest.check_player_privs(player_name, {server=true})
 		if not privs then
 			return
 		end
 
-		print('Fun Caves: '..name..' used the fixlight command')
+		print('Fun Caves: '..player_name..' used the fixlight command')
-		local player = minetest.get_player_by_name(name)
+		local player = minetest.get_player_by_name(player_name)
-		local pos = vector.round(player:getpos())
+		if not player then
+			return
+		end
+
+		local pos = player:getpos()
+		if not pos then
+			return
+		end
+		pos = vector.round(pos)
+
 		local radius = tonumber(param) or 50
 		radius = math.floor(radius)
 		local minp = vector.subtract(pos, radius)
 		local maxp = vector.add(pos, radius)
 
 		local vm = minetest.get_voxel_manip(minp, maxp)
+		if not vm then
+			return
+		end
+
 		--vm:set_lighting({day = 0, night = 0}, minp, maxp)
 		vm:calc_lighting(minp, maxp)
 		vm:update_liquids()
@@ -66,24 +104,39 @@ minetest.register_chatcommand("flatten", {
 	params = "<radius>",
 	description = "flatten terrain",
 	privs = {},
-	func = function(name, param)
+	func = function(player_name, param)
-		local privs = minetest.check_player_privs(name, {server=true})
+		if not (player_name and type(player_name) == 'string' and player_name ~= '') then
+			return
+		end
+
+		local privs = minetest.check_player_privs(player_name, {server=true})
 		if not privs then
 			return
 		end
 
-		print('Fun Caves: '..name..' used the flatten command')
+		print('Fun Caves: '..player_name..' used the flatten command')
-		local player = minetest.get_player_by_name(name)
+		local player = minetest.get_player_by_name(player_name)
-		local pos = vector.round(player:getpos())
+		if not player then
+			return
+		end
+
+		local pos = player:getpos()
+		if not pos then
+			return
+		end
+		pos = vector.round(pos)
+
 		local radius = tonumber(param) or 50
 		radius = math.floor(radius)
 		local minp = vector.subtract(pos, radius)
 		minp.y = minp.y - math.ceil(radius / 2)
 		local maxp = vector.add(pos, radius)
 		maxp.y = maxp.y + math.ceil(radius / 2)
+
 		local air = minetest.get_content_id('air')
 		local stone = minetest.get_content_id('default:stone')
 		local water = minetest.get_content_id('default:water_source')
+
 		local waters = {}
 		waters[minetest.get_content_id('default:water_source')] = true
 		waters[minetest.get_content_id('default:river_water_source')] = true
@@ -94,6 +147,10 @@ minetest.register_chatcommand("flatten", {
 		end
 
 		local vm = minetest.get_voxel_manip(minp, maxp)
+		if not vm then
+			return
+		end
+
 		local emin, emax = vm:read_from_map(minp, maxp)
 		local area = VoxelArea:new({MinEdge = emin, MaxEdge = emax})
 		local data = vm:get_data()
@@ -107,7 +164,7 @@ minetest.register_chatcommand("flatten", {
 				for y = maxp.y, minp.y, -1 do
 					if stones[data[ivm]] then
 						if y >= maxp.y then
-							print('Terrain altitude exceeds the radius.')
+							minetest.chat_send_player(player_name, 'Terrain altitude exceeds the given radius.')
 							return
 						end
 						heightmap[index] = y
@@ -119,7 +176,7 @@ minetest.register_chatcommand("flatten", {
 				end
 
 				if not heightmap[index] then
-					print('Terrain altitude exceeds the radius.')
+					minetest.chat_send_player(player_name, 'Terrain altitude exceeds the given radius.')
 					return
 				end
 

cloudgen.lua

@@ -1,4 +1,117 @@
-dofile(fun_caves.path .. "/deco_clouds.lua")
+
+local newnode = fun_caves.clone_node("default:dirt")
+newnode.description = "Cloud"
+newnode.tiles = {'fun_caves_cloud.png'}
+newnode.sunlight_propagates = true
+minetest.register_node("fun_caves:cloud", newnode)
+
+newnode = fun_caves.clone_node("default:dirt")
+newnode.description = "Storm Cloud"
+newnode.tiles = {'fun_caves_storm_cloud.png'}
+--newnode.sunlight_propagates = true
+minetest.register_node("fun_caves:storm_cloud", newnode)
+
+minetest.register_node("fun_caves:wispy_cloud", {
+	description = "Wispy Cloud",
+	tiles = {'fun_caves_wisp.png'},
+	sunlight_propagates = true,
+	use_texture_alpha = true,
+	drawtype = "glasslike",
+	paramtype = 'light',
+	walkable = false,
+	buildable_to = true,
+	pointable = false,
+})
+
+minetest.register_node("fun_caves:moon_weed", {
+	description = "Moon Weed",
+	drawtype = "plantlike",
+	tiles = {"fun_caves_moon_weed.png"},
+	inventory_image = "fun_caves_moon_weed.png",
+	waving = false,
+	sunlight_propagates = true,
+	paramtype = "light",
+	light_source = 8,
+	walkable = false,
+	groups = {snappy=3,flammable=2,flora=1,attached_node=1},
+	sounds = default.node_sound_leaves_defaults(),
+	selection_box = {
+		type = "fixed",
+		fixed = {-0.5, -0.5, -0.5, 0.5, -5/16, 0.5},
+	},
+})
+
+minetest.register_node("fun_caves:leaves_lumin", {
+	description = "Leaves",
+	drawtype = "allfaces_optional",
+	waving = 1,
+	visual_scale = 1.3,
+	tiles = {"default_leaves.png^[colorize:#FFDF00:150"},
+	special_tiles = {"default_leaves_simple.png^[colorize:#FFDF00:150"},
+	paramtype = "light",
+	is_ground_content = false,
+	light_source = 8,
+	groups = {snappy = 3, leafdecay = 4, flammable = 2, leaves = 1},
+	drop = {
+		max_items = 1,
+		items = {
+			--{
+			--	-- player will get sapling with 1/20 chance
+			--	items = {'default:sapling'},
+			--	rarity = 20,
+			--},
+			{
+				-- player will get leaves only if he get no saplings,
+				-- this is because max_items is 1
+				items = {'fun_caves:leaves_lumin'},
+			}
+		}
+	},
+	sounds = default.node_sound_leaves_defaults(),
+
+	after_place_node = default.after_place_leaves,
+})
+
+minetest.register_node("fun_caves:lumin_tree", {
+	description = "Lumin Tree",
+	tiles = {
+		"default_tree_top.png", "default_tree_top.png", "fun_caves_lumin_tree.png"
+	},
+	paramtype = "light",
+	drawtype = "nodebox",
+	node_box = {
+		type = "fixed", 
+		fixed = { {-0.25, -0.5, -0.25, 0.25, 0.5, 0.25}, }
+	},
+	paramtype2 = "facedir",
+	is_ground_content = false,
+	groups = {tree = 1, choppy = 2, flammable = 2},
+	sounds = default.node_sound_wood_defaults(),
+
+	on_place = minetest.rotate_node
+})
+
+newnode = fun_caves.clone_node("default:stone_with_iron")
+newnode.description = "Silver Lining"
+newnode.tiles = {'fun_caves_cloud.png^default_mineral_coal.png^[colorize:#FFFFFF:175'}
+newnode.drop = "fun_caves:silver_lump"
+minetest.register_node("fun_caves:silver_lining", newnode)
+
+minetest.register_craftitem("fun_caves:silver_lump", {
+	description = "Lump of Silver",
+	inventory_image = 'default_coal_lump.png^[colorize:#FFFFFF:175',
+})
+
+minetest.register_craftitem("fun_caves:silver_ingot", {
+	description = "Silver Ingot",
+	inventory_image = 'default_steel_ingot.png^[colorize:#FFFFFF:175',
+})
+
+minetest.register_craft({
+	type = "cooking",
+	output = "fun_caves:silver_ingot",
+	recipe = "fun_caves:silver_lump",
+})
 
 
 local max_depth = 31000
@@ -10,6 +123,10 @@ local plant_noise = {offset = 0.0, scale = 1.0, spread = {x = 200, y = 200, z =
 local biome_noise = {offset = 0.0, scale = 1.0, spread = {x = 400, y = 400, z = 400}, seed = -1471, octaves = 3, persist = 0.5, lacunarity = 2.0}
 
 fun_caves.cloudgen = function(minp, maxp, data, p2data, area, node)
+	if not (minp and maxp and data and p2data and area and node and type(data) == 'table' and type(p2data) == 'table') then
+		return
+	end
+
 	if minp.y ~= 4368 then
 		return
 	end
@@ -22,6 +139,9 @@ fun_caves.cloudgen = function(minp, maxp, data, p2data, area, node)
 	local cloud_2 = minetest.get_perlin_map(cloud_noise_2, map_max):get3dMap_flat(map_min)
 	local plant_n = minetest.get_perlin_map(plant_noise, {x=csize.x, y=csize.z}):get2dMap_flat({x=minp.x, y=minp.z})
 	local biome_n = minetest.get_perlin_map(biome_noise, {x=csize.x, y=csize.z}):get2dMap_flat({x=minp.x, y=minp.z})
+	if not (cloud_1 and cloud_2 and plant_n and biome_n) then
+		return
+	end
 
 	local write = false
 

deco.lua

@@ -137,6 +137,10 @@ end
 
 -- Create and initialize a table for a schematic.
 function fun_caves.schematic_array(width, height, depth)
+	if not (width and height and depth and type(width) == 'number' and type(height) == 'number' and type(depth) == 'number') then
+		return
+	end
+
 	-- Dimensions of data array.
 	local s = {size={x=width, y=height, z=depth}}
 	s.data = {}

deco_clouds.lua

@@ -1,114 +0,0 @@
-
-local newnode = fun_caves.clone_node("default:dirt")
-newnode.description = "Cloud"
-newnode.tiles = {'fun_caves_cloud.png'}
-newnode.sunlight_propagates = true
-minetest.register_node("fun_caves:cloud", newnode)
-
-newnode = fun_caves.clone_node("default:dirt")
-newnode.description = "Storm Cloud"
-newnode.tiles = {'fun_caves_storm_cloud.png'}
---newnode.sunlight_propagates = true
-minetest.register_node("fun_caves:storm_cloud", newnode)
-
-minetest.register_node("fun_caves:wispy_cloud", {
-	description = "Wispy Cloud",
-	tiles = {'fun_caves_wisp.png'},
-	sunlight_propagates = true,
-	use_texture_alpha = true,
-	drawtype = "glasslike",
-	paramtype = 'light',
-	walkable = false,
-	buildable_to = true,
-	pointable = false,
-})
-
-minetest.register_node("fun_caves:moon_weed", {
-	description = "Moon Weed",
-	drawtype = "plantlike",
-	tiles = {"fun_caves_moon_weed.png"},
-	inventory_image = "fun_caves_moon_weed.png",
-	waving = false,
-	sunlight_propagates = true,
-	paramtype = "light",
-	light_source = 8,
-	walkable = false,
-	groups = {snappy=3,flammable=2,flora=1,attached_node=1},
-	sounds = default.node_sound_leaves_defaults(),
-	selection_box = {
-		type = "fixed",
-		fixed = {-0.5, -0.5, -0.5, 0.5, -5/16, 0.5},
-	},
-})
-
-minetest.register_node("fun_caves:leaves_lumin", {
-	description = "Leaves",
-	drawtype = "allfaces_optional",
-	waving = 1,
-	visual_scale = 1.3,
-	tiles = {"default_leaves.png^[colorize:#FFDF00:150"},
-	special_tiles = {"default_leaves_simple.png^[colorize:#FFDF00:150"},
-	paramtype = "light",
-	is_ground_content = false,
-	light_source = 8,
-	groups = {snappy = 3, leafdecay = 4, flammable = 2, leaves = 1},
-	drop = {
-		max_items = 1,
-		items = {
-			--{
-			--	-- player will get sapling with 1/20 chance
-			--	items = {'default:sapling'},
-			--	rarity = 20,
-			--},
-			{
-				-- player will get leaves only if he get no saplings,
-				-- this is because max_items is 1
-				items = {'fun_caves:leaves_lumin'},
-			}
-		}
-	},
-	sounds = default.node_sound_leaves_defaults(),
-
-	after_place_node = default.after_place_leaves,
-})
-
-minetest.register_node("fun_caves:lumin_tree", {
-	description = "Lumin Tree",
-	tiles = {
-		"default_tree_top.png", "default_tree_top.png", "fun_caves_lumin_tree.png"
-	},
-	paramtype = "light",
-	drawtype = "nodebox",
-	node_box = {
-		type = "fixed", 
-		fixed = { {-0.25, -0.5, -0.25, 0.25, 0.5, 0.25}, }
-	},
-	paramtype2 = "facedir",
-	is_ground_content = false,
-	groups = {tree = 1, choppy = 2, flammable = 2},
-	sounds = default.node_sound_wood_defaults(),
-
-	on_place = minetest.rotate_node
-})
-
-newnode = fun_caves.clone_node("default:stone_with_iron")
-newnode.description = "Silver Lining"
-newnode.tiles = {'fun_caves_cloud.png^default_mineral_coal.png^[colorize:#FFFFFF:175'}
-newnode.drop = "fun_caves:silver_lump"
-minetest.register_node("fun_caves:silver_lining", newnode)
-
-minetest.register_craftitem("fun_caves:silver_lump", {
-	description = "Lump of Silver",
-	inventory_image = 'default_coal_lump.png^[colorize:#FFFFFF:175',
-})
-
-minetest.register_craftitem("fun_caves:silver_ingot", {
-	description = "Silver Ingot",
-	inventory_image = 'default_steel_ingot.png^[colorize:#FFFFFF:175',
-})
-
-minetest.register_craft({
-	type = "cooking",
-	output = "fun_caves:silver_ingot",
-	recipe = "fun_caves:silver_lump",
-})

deco_plants.lua

@@ -1,5 +1,9 @@
 fun_caves.water_plants = {}
 local function register_water_plant(desc)
+	if not (desc and type(desc) == 'table') then
+		return
+	end
+
 	fun_caves.water_plants[#fun_caves.water_plants+1] = desc
 end
 
@@ -129,6 +133,10 @@ for _, plant in ipairs(fun_caves.plantlist) do
 			},
 			sounds = plant.sounds or default.node_sound_leaves_defaults(),
 			after_dig_node = function(pos, oldnode, oldmetadata, digger)
+				if not (pos and oldnode) then
+					return
+				end
+
 				local replacement = oldnode.name:gsub('.*_water_(.*)', 'default:%1')
 				if replacement:find('cloud$') then
 					replacement = replacement:gsub('^default', 'fun_caves')
@@ -151,6 +159,10 @@ end
 
 
 local function register_flower(name, seed, biomes)
+	if not (name and seed and biomes and type(name) == 'string' and type(seed) == 'number' and type(biomes) == 'table') then
+		return
+	end
+
 	local param = {
 		deco_type = "simple",
 		place_on = {"default:dirt_with_grass"},

deco_rocks.lua

@@ -1,5 +1,9 @@
 -- Place a small nodebox.
 local function small_cube(grid, pos, diameters)
+	if not (grid and pos and diameters and type(grid) == 'table' and type(diameters) == 'table') then
+		return
+	end
+
 	local rock = {}
 
 	rock[1] = pos.x
@@ -83,6 +87,10 @@ minetest.register_node("fun_caves:small_rocks", {
 	groups = {stone=1, oddly_breakable_by_hand=3, dig_immediate = 3},
 	sounds = default.node_sound_stone_defaults(),
 	after_place_node = function(pos, placer, itemstack, pointed_thing)
+		if not pos then
+			return
+		end
+
 		minetest.set_node(pos, {name = "fun_caves:small_rocks"..math.random(6)})
 	end,
 })

decogen.lua

@@ -25,7 +25,11 @@ local plant_noise = {offset = 0.0, scale = 1.0, spread = {x = 200, y = 200, z =
 
 
 -- Air needs to be placed prior to decorations.
-fun_caves.decogen = function(minp, maxp, data, p2data, area, node, heightmap, biomemap, biome_ids, underzone, dis_map)
+fun_caves.decogen = function(minp, maxp, data, p2data, area, node, heightmap, biomemap, biome_ids, underzone)
+	if not (minp and maxp and data and p2data and area and node and type(data) == 'table' and type(p2data) == 'table') then
+		return
+	end
+
 	csize = vector.add(vector.subtract(maxp, minp), 1)
 
 	local map_max = {x = csize.x, y = csize.y + 2, z = csize.z}
@@ -33,6 +37,9 @@ fun_caves.decogen = function(minp, maxp, data, p2data, area, node, heightmap, bi
 
 	local biome_n = minetest.get_perlin_map(biome_noise, map_max):get3dMap_flat(map_min)
 	local plant_n = minetest.get_perlin_map(plant_noise, {x=csize.x, y=csize.z}):get2dMap_flat({x=minp.x, y=minp.z})
+	if not (biome_n and plant_n) then
+		return
+	end
 
 	local math_random = math.random
 	local dis_map = {}
@@ -350,7 +357,11 @@ fun_caves.decogen = function(minp, maxp, data, p2data, area, node, heightmap, bi
 										pos.x = x
 										pos.y = y
 										pos.z = z
-										local posm, count = minetest.find_nodes_in_area(pos, pos, desc.place_on)
+										local posm = minetest.find_nodes_in_area(pos, pos, desc.place_on)
+										if not (posm and type(posm) == 'table') then
+											return
+										end
+
 										if #posm > 0 then
 											node_match_cache[desc.content_id][data[ivm]] = "good" 
 										else

demon.lua

@@ -14,6 +14,10 @@ minetest.register_node("fun_caves:freezing_vapor", {
 })
 
 local function snow_effect(pos, radius)
+	if not (pos and radius and type(radius) == 'number') then
+		return
+	end
+
 	minetest.add_particlespawner({
 		amount = 30,
 		time = 1,
@@ -86,6 +90,10 @@ mobs:register_mob("fun_caves:ice_demon", {
 	animation_speed = 30,
 	fly_in = 'fun_caves:freezing_vapor',
 	do_custom = function(self)
+		if not self then
+			return
+		end
+
 		-- This has to happen fast.
 		if self.attack then
 			self.fly = true
@@ -163,6 +171,10 @@ local snow_demon = {
 	},
 	animation_speed = 30,
 	do_custom = function(self)
+		if not self then
+			return
+		end
+
 		if not self.attack then
 			self.fly = false
 		end
@@ -185,9 +197,17 @@ local snow_demon = {
 fun_caves.register_status({
 	name = 'slow_cold',
 	start = function(player)
+		if not player then
+			return
+		end
+
 		player:set_physics_override({speed=0.3})
 	end,
 	terminate = function(player)
+		if not player then
+			return
+		end
+
 		player:set_physics_override({speed=1})
 	end,
 })

elixir.lua

@@ -74,6 +74,7 @@ local elixir_ingredients = {
 	'fun_caves:orchid',
 	'fun_caves:petrified_wood',
 	'fun_caves:pillar_coral',
+	'fun_caves:silver_lump',
 	'fun_caves:small_rocks',
 	'fun_caves:staghorn_coral',
 	'fun_caves:stalactite',
@@ -148,16 +149,20 @@ if count > 15 then
 	})
 
 	minetest.register_on_craft(function(itemstack, player, old_craft_grid, craft_inv)
-		if itemstack:get_name() ~= "fun_caves:elixir" then
+		if not (player and itemstack and old_craft_grid and itemstack:get_name() == "fun_caves:elixir") then
 			return
 		end
 
 		local ingredients = {}
-		for i = 1, player:get_inventory():get_size("craft") do
+		local inv = player:get_inventory()
+		if not inv then
+			return
+		end
+
+		for i = 1, inv:get_size("craft") do
 			local name = old_craft_grid[i]:get_name()
-			if name ~= '' and name ~= 'fun_caves:syrup' and not name:find('green_slimeball$') then
+			if name ~= '' and name ~= 'fun_caves:syrup' and type(name) == 'string' and not name:find('green_slimeball$') then
 				ingredients[#ingredients+1] = name
-				--print(name)
 			end
 		end
 	end)
@@ -167,6 +172,10 @@ end
 fun_caves.register_status({
 	name = 'breathe',
 	terminate = function(player)
+		if not player then
+			return
+		end
+
 		local player_name = player:get_player_name()
 		minetest.chat_send_player(player_name, minetest.colorize('#FF0000', 'Your breathing becomes more difficult...'))
 	end,
@@ -176,8 +185,16 @@ minetest.register_craftitem("fun_caves:elixir_breathe", {
 	description = 'Dr Robertson\'s Patented Easy Breathing Elixir',
 	inventory_image = "fun_caves_elixir_breathe.png",
 	on_use = function(itemstack, user, pointed_thing)
+		if not (itemstack and user) then
+			return
+		end
+
 		local player_name = user:get_player_name()
-		fun_caves.set_status(user:get_player_name(), 'breathe', elixir_duration)
+		if not (player_name and type(player_name) == 'string' and player_name ~= '') then
+			return
+		end
+
+		fun_caves.set_status(player_name, 'breathe', elixir_duration)
 		minetest.chat_send_player(player_name, 'Your breathing becomes easier...')
 		itemstack:take_item()
 		return itemstack
@@ -207,6 +224,10 @@ minetest.register_craft({
 fun_caves.register_status({
 	name = 'damage_elixir',
 	terminate = function(player)
+		if not player then
+			return
+		end
+
 		local player_name = player:get_player_name()
 		minetest.chat_send_player(player_name, minetest.colorize('#FF0000', 'You feel weaker...'))
 		fun_caves.db.status[player_name].damage_elixir = nil
@@ -217,10 +238,22 @@ fun_caves.register_status({
 fun_caves.register_status({
 	name = 'armor_elixir',
 	terminate = function(player)
+		if not player then
+			return
+		end
+
 		local player_name = player:get_player_name()
+		if not (player_name and type(player_name) == 'string' and player_name ~= '') then
+			return
+		end
+
 		local armor_elixir = fun_caves.db.status[player_name].armor_elixir
 		local factor = armor_elixir.factor
 		local armor = player:get_armor_groups()
+		if not (armor and armor.fleshy) then
+			return
+		end
+
 		armor.fleshy = math.min(100, math.max(1, math.ceil(armor.fleshy / factor)))
 		player:set_armor_groups(armor)
 		minetest.chat_send_player(player_name, minetest.colorize('#FF0000', 'Your skin feels softer...'))
@@ -232,10 +265,22 @@ fun_caves.register_status({
 
 if fun_caves.expire_elixir_on_death then
 	minetest.register_on_dieplayer(function(player)
+		if not player then
+			return
+		end
+
 		local player_name = player:get_player_name()
+		if not (player_name and type(player_name) == 'string' and player_name ~= '') then
+			return
+		end
+
 		if fun_caves.db.status[player_name] and fun_caves.db.status[player_name].armor_elixir then
 			local factor = fun_caves.db.status[player_name].armor_elixir.factor
 			local armor = player:get_armor_groups()
+			if not (armor and armor.fleshy) then
+				return
+			end
+
 			armor.fleshy = math.min(100, math.max(1, math.ceil(armor.fleshy / factor)))
 			player:set_armor_groups(armor)
 			fun_caves.db.status[player_name].armor_elixir = nil
@@ -246,7 +291,14 @@ end
 
 
 local function increase_damage(user, bonus)
+	if not user then
+		return
+	end
+
 	local player_name = user:get_player_name()
+	if not (player_name and type(player_name) == 'string' and player_name ~= '') then
+		return
+	end
 
 	minetest.chat_send_player(player_name, 'You feel strong...')
 	fun_caves.set_status(player_name, 'damage_elixir', elixir_duration, {bonus = bonus})
@@ -254,8 +306,19 @@ end
 
 
 local function armor(user, factor)
+	if not user then
+		return
+	end
+
 	local player_name = user:get_player_name()
+	if not (player_name and type(player_name) == 'string' and player_name ~= '') then
+		return
+	end
+
 	local armor = user:get_armor_groups()
+	if not (armor and armor.fleshy) then
+		return
+	end
 
 	if fun_caves.db.status[player_name].armor_elixir then
 		local old_factor = fun_caves.db.status[player_name].armor_elixir.factor
@@ -297,6 +360,10 @@ if fun_caves.elixir_armor then
 			groups = {dig_immediate = 3, vessel = 1},
 			sounds = default.node_sound_glass_defaults(),
 			on_use = function(itemstack, user, pointed_thing)
+				if not (itemstack and user) then
+					return
+				end
+
 				armor(user, value)
 				itemstack:take_item()
 				return itemstack
@@ -347,6 +414,10 @@ for _, desc in pairs(descs) do
 		groups = {dig_immediate = 3, vessel = 1},
 		sounds = default.node_sound_glass_defaults(),
 		on_use = function(itemstack, user, pointed_thing)
+			if not (itemstack and user) then
+				return
+			end
+
 			increase_damage(user, bonus)
 			itemstack:take_item()
 			return itemstack

fortress.lua

@@ -89,7 +89,15 @@ newnode.description = "Treasure Chest"
 newnode.on_construct = nil
 newnode.drop = 'default:chest'
 newnode.on_rightclick = function(pos, node, clicker, itemstack, pointed_thing)
+	if not pos then
+		return
+	end
+
 	local meta = minetest.get_meta(pos)
+	if not meta then
+		return
+	end
+
 	local ready = meta:get_string('formspec')
 	if ready == '' then
 		local level = math.max(6, math.ceil(pos.y / math.floor(max_depth / 6)))
@@ -123,6 +131,10 @@ function table.shuffle(self)
 end
 
 function unionfind(max)
+	if not (max and type(max) == 'number') then
+		return
+	end
+
 	local u = { _parent = {}, _rank = {} }
 
 	for i = 0, max-1 do
@@ -164,6 +176,10 @@ end
 
 
 local function maze_floor(y2, minp, maxp, data, area, node)
+	if not (y2 and minp and maxp and data and area and node and type(y2) == 'number' and type(data) == 'table') then
+		return
+	end
+
 	-- walls is zero-based.
 	local walls = {}
 	for i = 0, 2 * cells * cells - 1 do
@@ -290,7 +306,12 @@ local designs = {
 		{0,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,0,0},
 	},
 }
+
 local function design_floor(y2, minp, maxp, data, area, node)
+	if not (y2 and minp and maxp and data and area and node and type(y2) == 'number' and type(data) == 'table') then
+		return
+	end
+
 	local design = designs[math.random(#designs)]
 
 	local py = minp.y + y2 * cell_size
@@ -341,6 +362,10 @@ end
 
 
 fun_caves.fortress = function(minp_in, maxp_in, data, area, node)
+	if not (minp_in and maxp_in and data and area and node and type(data) == 'table') then
+		return
+	end
+
 	-- hungry maze
 	-- chests (w traps)
 	-- step traps (math based)
@@ -357,6 +382,9 @@ fun_caves.fortress = function(minp_in, maxp_in, data, area, node)
 	local treasure_count = 0
 	local csize = vector.add(vector.subtract(maxp_in, minp_in), 1)
 	local floor_1 = minetest.get_perlin_map(floor_noise_1, {x=csize.x, y=csize.z}):get2dMap_flat({x=minp_in.x, y=minp_in.z})
+	if not floor_1 then
+		return
+	end
 
 	for y2 = 0, cells-1 do
 		local floor_type = math.random(20)

fungal_tree.lua

@@ -39,6 +39,10 @@ minetest.register_node("fun_caves:fungal_tree_fruit", {
 local fruit = minetest.get_content_id("fun_caves:fungal_tree_fruit")
 
 function fun_caves.make_fungal_tree(data, area, ivm, height)
+	if not (data and area and ivm and height and type(data) == 'table' and type(ivm) == 'number' and type(height) == 'number') then
+		return
+	end
+
 	local leaf = minetest.get_content_id(fungal_tree_leaves[math.random(#fungal_tree_leaves)])
 	local air = minetest.get_content_id('air')
 	for y = 0, height do

goblin.lua

@@ -61,7 +61,7 @@ local traps = {
 
 
 local function goblin_do(self)
-	if not fun_caves.custom_ready(self) then
+	if not (self and fun_caves.custom_ready(self)) then
 		return
 	end
 
@@ -412,7 +412,16 @@ minetest.register_abm({
 	interval = 1,
 	chance = 1,
 	action = function(pos, node, active_object_count, active_object_count_wider)
-		for _,object in ipairs(minetest.get_objects_inside_radius(pos, 0.95)) do -- IDKWTF this is but it works
+		if not pos then
+			return
+		end
+
+		local objects = minetest.get_objects_inside_radius(pos, 0.95)
+		if not (objects and type(objects) == 'table') then
+			return
+		end
+
+		for _, object in ipairs(objects) do -- IDKWTF this is but it works
 				if object:is_player() then
 					object:set_physics_override({speed = 0.1})
 					minetest.after(1, function() -- this effect is temporary
@@ -442,7 +451,16 @@ minetest.register_abm({
 	interval = 1,
 	chance = 1,
 	action = function(pos, node, active_object_count, active_object_count_wider)
-		for _,object in ipairs(minetest.get_objects_inside_radius(pos, 2)) do
+		if not pos then
+			return
+		end
+
+		local objects = minetest.get_objects_inside_radius(pos, 2)
+		if not (objects and type(objects) == 'table') then
+			return
+		end
+
+		for _, object in ipairs(objects) do
 			if object:is_player() then
 				minetest.set_node(pos, {name="fire:basic_flame"})
 				if object:get_hp() > 0 then
@@ -459,6 +477,10 @@ local diamond_trap
 if (not singleplayer and setting ~= true) or (singleplayer and setting == false) then
 	-- wimpier trap for non-tnt settings
 	diamond_trap = function(pos, player)
+		if not (pos and player) then
+			return
+		end
+
 		minetest.set_node(pos, {name="default:lava_source"})
 		if player:get_hp() > 0 then
 			player:set_hp(player:get_hp()-2)
@@ -468,8 +490,15 @@ if (not singleplayer and setting ~= true) or (singleplayer and setting == false)
 else
 	-- 5... 4... 3... 2... 1...
 	diamond_trap = function(pos, player)
+		if not (pos and player) then
+			return
+		end
+
 		minetest.set_node(pos, {name="tnt:tnt_burning"})
-		minetest.get_node_timer(pos):start(5)
+		local timer = minetest.get_node_timer(pos)
+		if timer then
+			timer:start(5)
+		end
 		minetest.sound_play("default_dig_crumbly", {pos = pos, gain = 0.5, max_hear_distance = 10})
 	end
 end
@@ -482,6 +511,10 @@ minetest.register_node("fun_caves:stone_with_diamond_trap", {
 	is_ground_content = false,
 	sounds = default.node_sound_stone_defaults(),
 	on_dig = function(pos, node, digger)
+		if not (pos and digger) then
+			return
+		end
+
 		if math.random(3) == 1 then
 			diamond_trap(pos, digger)
 		else
@@ -495,7 +528,16 @@ minetest.register_abm({
 	interval = 1,
 	chance = 1,
 	action = function(pos)
-		for _,object in ipairs(minetest.get_objects_inside_radius(pos, 3)) do
+		if not pos then
+			return
+		end
+
+		local objects = minetest.get_objects_inside_radius(pos, 3)
+		if not (objects and type(objects) == 'table') then
+			return
+		end
+
+		for _,object in ipairs(objects) do
 			if object:is_player() then
 				diamond_trap(pos, object)
 			end
@@ -536,6 +578,10 @@ bucket.register_liquid(
 )
 
 local gold_trap = function(pos, player)
+	if not (pos and player) then
+		return
+	end
+
 	minetest.set_node(pos, {name="fun_caves:molten_gold_source"})
 	minetest.sound_play("default_dig_crumbly", {pos = pos, gain = 0.5, max_hear_distance = 10})
 end
@@ -548,6 +594,10 @@ minetest.register_node("fun_caves:stone_with_gold_trap", {
 	is_ground_content = false,
 	sounds = default.node_sound_stone_defaults(),
 	on_dig = function(pos, node, digger)
+		if not (pos and digger) then
+			return
+		end
+
 		if math.random(3) == 1 then
 			gold_trap(pos, digger)
 		else
@@ -561,7 +611,16 @@ minetest.register_abm({
 	interval = 1,
 	chance = 1,
 	action = function(pos)
-		for _,object in ipairs(minetest.get_objects_inside_radius(pos, 2)) do
+		if not pos then
+			return
+		end
+
+		local objects = minetest.get_objects_inside_radius(pos, 2)
+		if not (objects and type(objects) == 'table') then
+			return
+		end
+
+		for _,object in ipairs(objects) do
 			if object:is_player() then
 				gold_trap(pos, object)
 			end
@@ -571,15 +630,24 @@ minetest.register_abm({
 
 
 local ice_trap = function(pos, player)
+		if not (pos and player) then
+			return
+		end
+
 	local ppos = player:getpos()
 	if ppos then
 		ppos.y = ppos.y + 1
 		local p1 = vector.subtract(ppos, 2)
 		local p2 = vector.add(ppos, 2)
 		local nodes = minetest.find_nodes_in_area(p1, p2, 'air')
+		if not (nodes and type(nodes) == 'table') then
+			return
+		end
+
 		for _, npos in pairs(nodes) do
 			minetest.set_node(npos, {name="default:ice"})
 		end
+
 		minetest.set_node(pos, {name="default:ice"})
 	end
 end
@@ -592,6 +660,10 @@ minetest.register_node("fun_caves:ice_trap", {
 	is_ground_content = false,
 	sounds = default.node_sound_stone_defaults(),
 	on_dig = function(pos, node, digger)
+		if not (pos and digger) then
+			return
+		end
+
 		if math.random(3) == 1 then
 			ice_trap(pos, digger)
 		else
@@ -605,7 +677,16 @@ minetest.register_abm({
 	interval = 1,
 	chance = 1,
 	action = function(pos)
-		for _,object in ipairs(minetest.get_objects_inside_radius(pos, 2)) do
+		if not pos then
+			return
+		end
+
+		local objects = minetest.get_objects_inside_radius(pos, 2)
+		if not (objects and type(objects) == 'table') then
+			return
+		end
+
+		for _,object in ipairs(objects) do
 			if object:is_player() then
 				ice_trap(pos, object)
 			end
@@ -615,6 +696,10 @@ minetest.register_abm({
 
 
 local function lightning_effects(pos, radius)
+		if not (pos and radius) then
+			return
+		end
+
 	minetest.add_particlespawner({
 		amount = 30,
 		time = 1,
@@ -633,6 +718,10 @@ local function lightning_effects(pos, radius)
 end
 
 local copper_trap = function(pos, player)
+	if not (pos and player) then
+		return
+	end
+
 	if player:get_hp() > 0 then
 		player:set_hp(player:get_hp()-1)
 		lightning_effects(pos, 3)
@@ -648,6 +737,10 @@ minetest.register_node("fun_caves:stone_with_copper_trap", {
 	is_ground_content = false,
 	sounds = default.node_sound_stone_defaults(),
 	on_dig = function(pos, node, digger)
+		if not (pos and digger) then
+			return
+		end
+
 		if math.random(3) == 1 then
 			copper_trap(pos, digger)
 		else
@@ -662,7 +755,16 @@ minetest.register_abm({
 	interval = 1,
 	chance = 2,
 	action = function(pos)
-		for _,object in ipairs(minetest.get_objects_inside_radius(pos, 3)) do
+		if not pos then
+			return
+		end
+
+		local objects = minetest.get_objects_inside_radius(pos, 3)
+		if not (objects and type(objects) == 'table') then
+			return
+		end
+
+		for _,object in ipairs(objects) do
 			if object:is_player() then
 				copper_trap(pos, object)
 			end
@@ -681,6 +783,10 @@ minetest.register_node("fun_caves:stone_with_iron_trap", {
 	is_ground_content = false,
 	sounds = default.node_sound_stone_defaults(),
 	on_dig = function(pos, node, digger)
+		if not (pos and digger) then
+			return
+		end
+
 		if math.random(3) == 1 then
 			copper_trap(pos, digger)
 		else
@@ -694,7 +800,16 @@ minetest.register_abm({
 	interval = 2,
 	chance = 2,
 	action = function(pos, node, active_object_count, active_object_count_wider)
-		for _,object in ipairs(minetest.get_objects_inside_radius(pos, 2)) do
+		if not pos then
+			return
+		end
+
+		local objects = minetest.get_objects_inside_radius(pos, 3)
+		if not (objects and type(objects) == 'table') then
+			return
+		end
+
+		for _, object in ipairs(objects) do
 			if object:is_player() then
 				copper_trap(pos, object)
 			end

mapgen.lua

@@ -8,9 +8,14 @@ local fortress_noise = {offset = 0, scale = 1, seed = -4082, spread = {x = 7, y
 -- This tables looks up nodes that aren't already stored.
 local node = setmetatable({}, {
 	__index = function(t, k)
+		if not (t and k and type(t) == 'table') then
+			return
+		end
+
 		t[k] = minetest.get_content_id(k)
 		return t[k]
-	end})
+	end
+})
 
 local data = {}
 local p2data = {}  -- vm rotation data buffer
@@ -41,6 +46,10 @@ end
 --end
 
 fun_caves.is_fortress = function(pos, cs)
+	if not pos then
+		return
+	end
+
 	-- Fix this to get csize, somehow.
 	-- Remember that this function may be called
 	--  before any chunks are generated.
@@ -60,6 +69,10 @@ fun_caves.is_fortress = function(pos, cs)
 	local z = math.floor((pos.z + offset) / cs.z)
 
 	local n = minetest.get_perlin(fortress_noise):get3d({x=x, y=y, z=z})
+	if not (n and type(n) == 'number') then
+		return
+	end
+
 	if math.floor((n * 10000) % (fun_caves.DEBUG and 4 or 19)) == 1 then
 		return true
 	end
@@ -68,6 +81,10 @@ fun_caves.is_fortress = function(pos, cs)
 end
 
 fun_caves.place_schematic = function(minp, maxp, data, p2data, area, node, pos, schem, center)
+	if not (minp and maxp and data and p2data and area and node and pos and schem and type(data) == 'table' and type(p2data) == 'table' and type(schem) == 'table') then
+		return
+	end
+
 	local rot = math.random(4) - 1
 	local yslice = {}
 	if schem.yslice_prob then
@@ -119,6 +136,10 @@ fun_caves.place_schematic = function(minp, maxp, data, p2data, area, node, pos,
 end
 
 fun_caves.surround = function(node, data, area, ivm)
+	if not (node and data and area and ivm and type(data) == 'table' and type(ivm) == 'number') then
+		return
+	end
+
 	-- Check to make sure that a plant root is fully surrounded.
 	-- This is due to the kludgy way you have to make water plants
 	--  in minetest, to avoid bubbles.
@@ -345,8 +366,16 @@ fun_caves.cave_biomes = {
 
 
 local function generate(p_minp, p_maxp, seed)
+	if not (p_minp and p_maxp and seed) then
+		return
+	end
+
 	local minp, maxp = p_minp, p_maxp
 	local vm, emin, emax = minetest.get_mapgen_object("voxelmanip")
+	if not (vm and emin and emax) then
+		return
+	end
+
 	vm:get_data(data)
 	p2data = vm:get_param2_data()
 	local heightmap
@@ -358,7 +387,14 @@ local function generate(p_minp, p_maxp, seed)
 	end
 
 	-- use the same seed (based on perlin noise).
-	math.randomseed(minetest.get_perlin(seed_noise):get2d({x=minp.x, y=minp.z}))
+	do
+		local seed = minetest.get_perlin(seed_noise):get2d({x=minp.x, y=minp.z})
+		if not (seed and type(seed) == 'number') then
+			return
+		end
+
+		math.randomseed(seed)
+	end
 
 	local write = false
 	local write_p2, write_p4 = false, false

mobs.lua

@@ -1,12 +1,19 @@
 -- search/replace -- lets mobs change the terrain
 -- used for goblin traps and torch thieving
 fun_caves.search_replace = function(pos, search_rate, replace_what, replace_with)
+	if not (pos and search_rate and replace_what and replace_with and type(search_rate) == 'number' and type(replace_what) == 'string' and type(replace_with) == 'string') then
+		return
+	end
+
 	if math.random(search_rate) == 1 then
 		local p1 = vector.subtract(pos, 1)
 		local p2 = vector.add(pos, 1)
 
 		--look for nodes
 		local nodelist = minetest.find_nodes_in_area(p1, p2, replace_what)
+		if not (nodelist and type(nodelist) == 'table') then
+			return
+		end
 
 		if #nodelist > 0 then
 			for _, new_pos in pairs(nodelist) do 
@@ -18,6 +25,10 @@ fun_caves.search_replace = function(pos, search_rate, replace_what, replace_with
 end
 
 function fun_caves.climb(self)
+	if not self then
+		return
+	end
+
 	if self.state == "stand" and math.random() < 0.2 then
 		if self.fall_speed == 2 then
 			self.fall_speed = -2
@@ -31,44 +42,61 @@ end
 
 -- causes mobs to take damage from hot/cold surfaces
 fun_caves.surface_damage = function(self, cold_natured)
-	--if not self.fun_caves_damage_timer then
+	if not self then
-	--	self.fun_caves_damage_timer = 0
+		return
-	--end
+	end
 
-	--self.fun_caves_damage_timer = self.fun_caves_damage_timer + 1
+	local pos = self.object:getpos()
-	--if self.fun_caves_damage_timer > 30 then
+	if not pos then
-	--	self.fun_caves_damage_timer = 0
+		return
-		local pos = self.object:getpos()
+	end
-		local minp = vector.subtract(pos, 1.5)
+
-		local maxp = vector.add(pos, 1.5)
+	local minp = vector.subtract(pos, 1.5)
-		local counts = 0
+	local maxp = vector.add(pos, 1.5)
-		if self.lava_damage > 1 then
+	local counts = 0
-			counts =  minetest.find_nodes_in_area(minp, maxp, {"group:surface_hot"})
+	if self.lava_damage > 1 then
-			if #counts > 0 then
+		counts =  minetest.find_nodes_in_area(minp, maxp, {"group:surface_hot"})
-				self.health = self.health - math.floor(self.lava_damage / 2)
+		if not (counts and type(counts) == 'table') then
-				effect(pos, 5, "fire_basic_flame.png")
+			return
-			end
 		end
 
-		if not cold_natured then
+		if #counts > 0 then
-			counts =  minetest.find_nodes_in_area(minp, maxp, {"group:surface_cold"})
+			self.health = self.health - math.floor(self.lava_damage / 2)
-			if #counts > 0 then
+			effect(pos, 5, "fire_basic_flame.png")
-				self.health = self.health - 1
+		end
-			end
+	end
+
+	if not cold_natured then
+		counts =  minetest.find_nodes_in_area(minp, maxp, {"group:surface_cold"})
+		if not (counts and type(counts) == 'table') then
+			return
 		end
 
-		check_for_death(self)
+		if #counts > 0 then
-	--end
+			self.health = self.health - 1
+		end
+	end
+
+	check_for_death(self)
 end
 
 -- executed in a mob's do_custom() to regulate their actions
 -- if false, do nothing
 local custom_delay = 2000000
 fun_caves.custom_ready = function(self, delay)
+	if not self then
+		return
+	end
+
 	local time = minetest.get_us_time()
+	if not (time and type(time) == 'number') then
+		return
+	end
+
 	if not delay then
 		delay = custom_delay
 	end
+
 	if not self.custom_time or time - self.custom_time > delay then
 		self.custom_time = time
 		return true
@@ -156,12 +184,17 @@ for _, mob in pairs(mob_stats) do
 end
 
 local function fun_caves_punch(self, puncher, time_from_last_punch, tool_capabilities, dir)
+	if not self then
+		return
+	end
+
 	if puncher and puncher.get_player_name then
 		local player_name = puncher:get_player_name()
-		if player_name and player_name ~= '' and fun_caves.db.status[player_name] and fun_caves.db.status[player_name].damage_elixir and tool_capabilities and tool_capabilities.damage_groups and tool_capabilities.damage_groups.fleshy then
+		if player_name and type(player_name) == 'string' and player_name ~= '' and fun_caves.db.status[player_name] and fun_caves.db.status[player_name].damage_elixir and tool_capabilities and tool_capabilities.damage_groups and tool_capabilities.damage_groups.fleshy then
 			tool_capabilities.damage_groups.fleshy = tool_capabilities.damage_groups.fleshy + fun_caves.db.status[player_name].damage_elixir.bonus
 		end
 	end
+
 	self.on_punch_orig(self, puncher, time_from_last_punch, tool_capabilities, dir)
 end
 
@@ -214,6 +247,10 @@ if minetest.registered_entities["dmobs:dragon"] and minetest.registered_entities
 
 	local m = table.copy(minetest.registered_entities["mobs_yeti:snowball"])
 	m.hit_player = function(self, player)
+		if not (self and player) then
+			return
+		end
+
 		player:punch(self.object, 1.0, {
 			full_punch_interval = 1.0,
 			damage_groups = {fleshy = 8},
@@ -221,6 +258,10 @@ if minetest.registered_entities["dmobs:dragon"] and minetest.registered_entities
 	end
 
 	m.hit_mob = function(self, player)
+		if not (self and player) then
+			return
+		end
+
 		player:punch(self.object, 1.0, {
 			full_punch_interval = 1.0,
 			damage_groups = {fleshy = 8},
@@ -236,7 +277,7 @@ if minetest.registered_entities["dmobs:fox"] then
 	-- fire_walk overwrites bones, under some circumstances.
 	-- Keep it disabled until it's definitely working.
 	local function fire_walk(self)
-		if not fun_caves.custom_ready(self, 1000000) then
+		if not (self and fun_caves.custom_ready(self, 1000000)) then
 			return
 		end
 
@@ -246,6 +287,10 @@ if minetest.registered_entities["dmobs:fox"] then
 
 		--look for nodes
 		local nodelist = minetest.find_nodes_in_area(p1, p2, "air")
+		if not (nodelist and type(nodelist) == 'table') then
+			return
+		end
+
 		for n in pairs(nodelist) do
 			--minetest.set_node(pos, {name='fire:basic_flame'})
 		end
@@ -310,7 +355,7 @@ mobs:register_mob("fun_caves:star", {
 	fall_damage = 0,
 	lifetimer = 360,
 	do_custom = function(self)
-		if not fun_caves.custom_ready(self) then
+		if not (self and fun_caves.custom_ready(self)) then
 			return
 		end
 
@@ -326,7 +371,7 @@ mobs:spawn_specific("fun_caves:star", {'default:stone', 'fun_caves:asteroid_wate
 
 if minetest.registered_entities["mobs:bee"] then
 	local function bee_summon(self)
-		if self.state ~= 'attack' then
+		if not (self and self.state == 'attack') then
 			return
 		end
 
@@ -345,11 +390,14 @@ if minetest.registered_entities["mobs:bee"] then
 
 			--look for nodes
 			local nodelist = minetest.find_nodes_in_area(p1, p2, "air")
+			if not (nodelist and type(nodelist) == 'table') then
+				return
+			end
 
 			if #nodelist > 0 then
 				for key,value in pairs(nodelist) do 
 					minetest.add_entity(value, "fun_caves:killer_bee_drone")
-					print("A bee summons reinforcement.")
+					print("Fun Caves: A bee summons reinforcement.")
 					return  -- only one at a time
 				end
 			end
@@ -357,7 +405,7 @@ if minetest.registered_entities["mobs:bee"] then
 	end
 
 	local function bee_do(self)
-		if not fun_caves.custom_ready(self) then
+		if not (self and fun_caves.custom_ready(self)) then
 			return
 		end
 
@@ -513,7 +561,7 @@ if minetest.registered_entities["mobs_monster:spider"] then
 	}
 	m.water_damage = 0
 	m.do_custom = function(self)
-		if not fun_caves.custom_ready(self) then
+		if not (self and fun_caves.custom_ready(self)) then
 			return
 		end
 
@@ -540,7 +588,7 @@ if minetest.registered_entities["mobs_monster:spider"] then
 	}
 	m.water_damage = 0
 	m.do_custom = function(self)
-		if not fun_caves.custom_ready(self) then
+		if not (self and fun_caves.custom_ready(self)) then
 			return
 		end
 
@@ -573,7 +621,7 @@ if minetest.registered_entities["mobs_monster:spider"] then
 		{name = "farming:cotton", chance = 2, min = 1, max = 2},
 	}
 	m.do_custom = function(self)
-		if not fun_caves.custom_ready(self) then
+		if not (self and fun_caves.custom_ready(self)) then
 			return
 		end
 
@@ -608,6 +656,10 @@ if minetest.registered_entities["mobs_monster:spider"] then
 	m.jump = false
 	m.drops = { {name = "mobs:meat_raw", chance = 1, min = 1, max = 1}, }
 	m.do_custom = function(self)
+		if not self then
+			return
+		end
+
 		if not self.fun_caves_damage_timer then
 			self.fun_caves_damage_timer = 0
 		end

nodes.lua

@@ -4,6 +4,10 @@ local max_depth = 31000
 
 local old_is_protected = minetest.is_protected
 function minetest.is_protected(pos, name)
+	if not (pos and name and type(name) == 'string') then
+		return
+	end
+
 	local node = get_node_or_nil(pos)
 	if node and get_item_group(node.name, "fortress") ~= 0 then
 		return true
@@ -133,6 +137,10 @@ minetest.register_craft({
 })
 
 local function rope_remove(pos)
+	if not pos then
+		return
+	end
+
 	for i = 1, 100 do
 		local newpos = table.copy(pos)
 		newpos.y = newpos.y - i
@@ -166,19 +174,21 @@ for length = 10, 50, 10 do
 		legacy_wallmounted = true,
 		sounds = default.node_sound_leaves_defaults(),
 		after_place_node = function(pos, placer, itemstack, pointed_thing)
-			if pointed_thing and pointed_thing.above then
+			if not (pointed_thing and pointed_thing.above) then
-				local pos = pointed_thing.above
+				return
-				local orig = minetest.get_node_or_nil(pos)
+			end
-				if orig and orig.name and orig.param2 and good_params[orig.param2] then
+
-					for i = 1, length do
+			local pos_old = pointed_thing.above
-						local newpos = table.copy(pos)
+			local orig = minetest.get_node_or_nil(pos_old)
-						newpos.y = newpos.y - i
+			if orig and orig.name and orig.param2 and good_params[orig.param2] then
-						local node = minetest.get_node_or_nil(newpos)
+				for i = 1, length do
-						if node and node.name and node.name == 'air' then
+					local newpos = table.copy(pos_old)
-							minetest.set_node(newpos, {name='fun_caves:rope_ladder_piece', param2=orig.param2})
+					newpos.y = newpos.y - i
-						else
+					local node = minetest.get_node_or_nil(newpos)
-							break
+					if node and node.name and node.name == 'air' then
-						end
+						minetest.set_node(newpos, {name='fun_caves:rope_ladder_piece', param2=orig.param2})
+					else
+						break
 					end
 				end
 			end

pyramid.lua

@@ -34,7 +34,15 @@ newnode.light_source = 1
 newnode.on_construct = nil
 newnode.drop = 'default:chest'
 newnode.on_rightclick = function(pos, node, clicker, itemstack, pointed_thing)
+	if not (pos and clicker) then
+		return
+	end
+
 	local meta = minetest.get_meta(pos)
+	if not meta then
+		return
+	end
+
 	local ready = meta:get_string('formspec')
 
 	if ready == '' then
@@ -65,6 +73,10 @@ local pyramid_noise_1 = {offset = 0, scale = 1, seed = -6012, spread = {x = 20,
 
 
 fun_caves.pyramid = function(minp, maxp, data, p2data, area, biomemap, biome_ids, node, heightmap)
+	if not (minp and maxp and data and p2data and area and node and type(data) == 'table' and type(p2data) == 'table') then
+		return
+	end
+
 	if math.random(20) ~= 1 then
 		return
 	end
@@ -104,6 +116,9 @@ fun_caves.pyramid = function(minp, maxp, data, p2data, area, biomemap, biome_ids
 	local map_min = {x = minp.x, y = minp.y, z = minp.z}
 
 	local pyramid_1 = minetest.get_perlin_map(pyramid_noise_1, map_max):get3dMap_flat(map_min)
+	if not pyramid_1 then
+		return
+	end
 
 	local write = true
 	local p2write = false

skyseagen.lua

@@ -17,6 +17,10 @@ local plant_noise = {offset = 0.0, scale = 1.0, spread = {x = 200, y = 200, z =
 local biome_noise = {offset = 0.0, scale = 1.0, spread = {x = 400, y = 400, z = 400}, seed = -1471, octaves = 3, persist = 0.5, lacunarity = 2.0}
 
 fun_caves.skysea = function(minp, maxp, data, p2data, area, node)
+	if not (minp and maxp and data and p2data and area and node and type(data) == 'table' and type(p2data) == 'table') then
+		return
+	end
+
 	if minp.y ~= 8768 then
 		return
 	end
@@ -26,6 +30,9 @@ fun_caves.skysea = function(minp, maxp, data, p2data, area, node)
 	local terrain_1 = minetest.get_perlin_map(terrain_noise_1, {x=csize.x, y=csize.z}):get2dMap_flat({x=minp.x, y=minp.z})
 	local plant_n = minetest.get_perlin_map(plant_noise, {x=csize.x, y=csize.z}):get2dMap_flat({x=minp.x, y=minp.z})
 	local biome_n = minetest.get_perlin_map(biome_noise, {x=csize.x, y=csize.z}):get2dMap_flat({x=minp.x, y=minp.z})
+	if not (terrain_1 and plant_n and biome_n) then
+		return
+	end
 
 	local write = false
 

spec_bomb.lua

@@ -1,9 +1,17 @@
 local function disintigrate(pos, radius, node_name, user_name, dropped)
+	if not (pos and radius and node_name and user_name and type(radius) == 'number' and type(user_name) == 'string') then
+		return
+	end
+
 	local node_id = minetest.get_content_id(node_name)
 	local air = minetest.get_content_id('air')
 	local minp = vector.subtract(pos, radius)
 	local maxp = vector.add(pos, radius)
 	local vm = minetest.get_voxel_manip()
+	if not vm then
+		return
+	end
+
 	local emin, emax = vm:read_from_map(minp, maxp)
 	local area = VoxelArea:new({MinEdge = emin, MaxEdge = emax})
 	local data = vm:get_data()
@@ -50,6 +58,10 @@ end
 
 
 local function floor(pos, blocks, node_name, user_name)
+	if not (pos and blocks and node_name and user_name and type(blocks) == 'number' and type(node_name) == 'string' and type(user_name) == 'string') then
+		return
+	end
+
 	local p = {y = pos.y}
 	local count = 0
 	for r = 1, blocks do
@@ -90,14 +102,21 @@ for _, node in pairs(nodes) do
 	newnode.inventory_image = '[inventorycube{tnt_top.png{'..node_texture..'{tnt_side.png'
 	newnode.drop = bomb_name
 	newnode.on_punch = function(pos, node, puncher, pointed_thing)
-		if puncher:get_wielded_item():get_name() ~= "default:torch" then
+		if not (pos and puncher) then
 			return
 		end
+
+		local wield = puncher:get_wielded_item()
+		if not wield or wield:get_name() ~= "default:torch" then
+			return
+		end
+
 		minetest.after(5, function()
 			local pos_node = minetest.get_node_or_nil(pos)
-			if pos_node.name ~= bomb_name then
+			if not (pos_node and pos_node.name == bomb_name) then
 				return
 			end
+
 			disintigrate(pos, 5, node_name, puncher:get_player_name(), comp)
 			minetest.remove_node(pos)
 		end)
@@ -137,14 +156,21 @@ for _, node in pairs(nodes) do
 	newnode.inventory_image = '[inventorycube{'..node_texture..'{'..node_texture..'{'..node_texture..'^fun_caves_expand.png'
 	newnode.drop = bomb_name
 	newnode.on_punch = function(pos, node, puncher, pointed_thing)
-		if puncher:get_wielded_item():get_name() ~= "default:torch" then
+		if not (pos and puncher) then
 			return
 		end
+
+		local wield = puncher:get_wielded_item()
+		if not wield or wield:get_name() ~= "default:torch" then
+			return
+		end
+
 		minetest.after(5, function()
 			local pos_node = minetest.get_node_or_nil(pos)
-			if pos_node.name ~= bomb_name then
+			if not (pos_node and pos_node.name == bomb_name) then
 				return
 			end
+
 			floor(pos, 100, node_name, puncher:get_player_name())
 			minetest.set_node(pos, {name = node_name})
 		end)
@@ -217,6 +243,10 @@ local function power(player, pos, tool_type, max)
 
 	local air = minetest.get_content_id('air')
 	local vm = minetest.get_voxel_manip()
+	if not vm then
+		return
+	end
+
 	local emin, emax = vm:read_from_map(minp, maxp)
 	local area = VoxelArea:new({MinEdge = emin, MaxEdge = emax})
 	local data = vm:get_data()
@@ -270,7 +300,10 @@ local function power(player, pos, tool_type, max)
 		local tp = tool:get_tool_capabilities()
 		local def = ItemStack({name=names[id]}):get_definition()
 		local dp = minetest.get_dig_params(def.groups, tp)
-		print(dp.wear)
+		if not dp then
+			return
+		end
+
 		tool:add_wear(dp.wear * number)
 	end
 
@@ -289,11 +322,16 @@ minetest.register_tool("fun_caves:chainsaw", {
 		damage_groups = {fleshy=4},
 	},
 	on_use = function(itemstack, user, pointed_thing)
+		if not (user and pointed_thing) then
+			return
+		end
+
 		minetest.sound_play('chainsaw', {
 			object = user,
 			gain = 0.1,
 			max_hear_distance = 30
 		})
+
 		return power(user, pointed_thing.under, 'axe')
 	end,
 })
@@ -310,11 +348,16 @@ minetest.register_tool("fun_caves:jackhammer", {
 		damage_groups = {fleshy=4},
 	},
 	on_use = function(itemstack, user, pointed_thing)
+		if not (user and pointed_thing) then
+			return
+		end
+
 		minetest.sound_play('jackhammer', {
 			object = user,
 			gain = 0.1,
 			max_hear_distance = 30
 		})
+
 		return power(user, pointed_thing.under, 'pick')
 	end,
 })

tesseract.lua

@@ -1,12 +1,15 @@
 local max_depth = 31000
 
 local function teleporter(user, area, power)
-	if not user then
+	if not (user and area and power and type(power) == 'number') then
 		return
 	end
 
 	local name = user:get_player_name()
 	local pos = user:getpos()
+	if not (name and pos and name ~= '' and type(name) == 'string') then
+		return
+	end
 
 	if not fun_caves.db.teleport_data[name] then
 		fun_caves.db.teleport_data[name] = {}
@@ -84,10 +87,18 @@ local function teleporter(user, area, power)
 
 				c1 = minetest.get_perlin(fun_caves.cave_noise_1):get3d(newpos)
 				c2 = minetest.get_perlin(fun_caves.cave_noise_2):get3d(newpos)
+				if not (c1 and c2 and type(c1) == 'number' and type(c2) == 'number') then
+					return
+				end
+
 				if c1 * c2 > fun_caves.cave_width then
 					newpos.y = newpos.y - 1
 					c1 = minetest.get_perlin(fun_caves.cave_noise_1):get3d(newpos)
 					c2 = minetest.get_perlin(fun_caves.cave_noise_2):get3d(newpos)
+					if not (c1 and c2 and type(c1) == 'number' and type(c2) == 'number') then
+						return
+					end
+
 					if c1 * c2 > fun_caves.cave_width then
 						good = true
 						break
@@ -312,7 +323,15 @@ minetest.register_craft({
 
 
 local function translocate(pos, node, clicker, itemstack, pointed_thing)
+	if not (pos and clicker) then
+		return
+	end
+
 	local meta = minetest.get_meta(pos)
+	if not meta then
+		return
+	end
+
 	local id = meta:get_string('id')
 	local owner = meta:get_string('owner')
 	if not (id and tonumber(id)) then
@@ -348,6 +367,10 @@ local function translocate(pos, node, clicker, itemstack, pointed_thing)
 
 			minetest.set_node(pos2, {name = 'fun_caves:translocator'})
 			local meta = minetest.get_meta(pos2)
+			if not meta then
+				return
+			end
+
 			meta:set_string('id', id)
 			meta:set_string('owner', owner)
 
@@ -357,19 +380,21 @@ local function translocate(pos, node, clicker, itemstack, pointed_thing)
 end
 
 local function trans_use(itemstack, user, pointed_thing)
-	if not itemstack then
+	if not (itemstack and user) then
 		return
 	end
+
 	local data = minetest.deserialize(itemstack:get_metadata())
 	if not (data and data.id) then
 		return
 	end
+
 	local player_name = user:get_player_name()
 	minetest.chat_send_player(player_name, "You see a serial number: "..data.id)
 end
 
 local function trans_place(itemstack, placer, pointed_thing)
-	if not (itemstack and pointed_thing) then
+	if not (itemstack and placer and pointed_thing) then
 		return
 	end
 
@@ -395,6 +420,10 @@ local function trans_place(itemstack, placer, pointed_thing)
 	if place_good then
 		pair[#pair+1] = pos
 		local meta = minetest.get_meta(pos)
+		if not meta then
+			return
+		end
+
 		meta:set_string('id', data.id)
 		meta:set_string('owner', data.owner)
 	end
@@ -402,7 +431,7 @@ local function trans_place(itemstack, placer, pointed_thing)
 end
 
 local function trans_dig(pos, node, digger)
-	if not (pos and digger) then
+	if not (pos and node and digger) then
 		return
 	end
 
@@ -412,6 +441,10 @@ local function trans_dig(pos, node, digger)
 	end
 
 	local meta = minetest.get_meta(pos)
+	if not meta then
+		return
+	end
+
 	local id = meta:get_string('id')
 	local owner = meta:get_string('owner')
 	if owner == '' then
@@ -452,7 +485,15 @@ local function trans_dig(pos, node, digger)
 end
 
 local function trans_dest(pos)
+	if not pos then
+		return
+	end
+
 	local meta = minetest.get_meta(pos)
+	if not meta then
+		return
+	end
+
 	local id = meta:get_string('id')
 	local owner = meta:get_string('owner')
 	if not (id and owner) then
@@ -470,6 +511,10 @@ local function trans_dest(pos)
 		end
 		minetest.set_node(pos, {name = 'fun_caves:translocator'})
 		local meta = minetest.get_meta(pos)
+		if not meta then
+			return
+		end
+
 		meta:set_string('id', id)
 		meta:set_string('owner', owner)
 
@@ -515,7 +560,7 @@ for _, gem in pairs(gems) do
 end
 
 minetest.register_on_craft(function(itemstack, player, old_craft_grid, craft_inv)
-	if itemstack:get_name() ~= "fun_caves:translocator" then
+	if not (itemstack and player and itemstack:get_name() == "fun_caves:translocator") then
 		return
 	end
 

treegen.lua

@@ -178,28 +178,6 @@ minetest.register_node("fun_caves:syrup", {
 	sounds = default.node_sound_glass_defaults(),
 })
 
-minetest.register_on_craft(function(itemstack, player, old_craft_grid, craft_inv)
-	local name = itemstack:get_name()
-	if not (name and name == 'fun_caves:syrup') then
-		return
-	end
-
-	local bucket
-	local index
-	for i = 1, player:get_inventory():get_size("craft") do
-		if (old_craft_grid[i]:get_name()):find('^fun_caves:bucket') then
-			bucket = old_craft_grid[i]:get_name()
-			index = i
-		end
-	end
-	if not bucket then
-		return
-	end
-
-	bucket = bucket:gsub('sap', 'empty')
-	craft_inv:set_stack("craft", index, bucket)
-end)
-
 newnode = fun_caves.clone_node("default:tree")
 newnode.description = "Glowing Fungal Wood"
 newnode.tiles = {"fun_caves_tree.png^vmg_glowing_fungal.png",}
@@ -282,6 +260,32 @@ minetest.register_craft({
 	},
 })
 
+minetest.register_on_craft(function(itemstack, player, old_craft_grid, craft_inv)
+	if not (itemstack and player and old_craft_grid and craft_inv) then
+		return
+	end
+
+	local name = itemstack:get_name()
+	if not (name and name == 'fun_caves:syrup') then
+		return
+	end
+
+	local bucket
+	local index
+	for i = 1, player:get_inventory():get_size("craft") do
+		if (old_craft_grid[i]:get_name()):find('^fun_caves:bucket') then
+			bucket = old_craft_grid[i]:get_name()
+			index = i
+		end
+	end
+	if not bucket then
+		return
+	end
+
+	bucket = bucket:gsub('sap', 'empty')
+	craft_inv:set_stack("craft", index, bucket)
+end)
+
 minetest.register_craft({
 	type = "cooking",
 	output = "fun_caves:amber",
@@ -305,8 +309,12 @@ local wood_noise = {offset = 0, scale = 1, seed = -4640, spread = {x = 32, y = 3
 
 
 fun_caves.treegen = function(minp, maxp, data, p2data, area, node)
+	if not (minp and maxp and data and p2data and area and node and type(data) == 'table' and type(p2data) == 'table') then
+		return
+	end
+
 	local tree_n = minetest.get_perlin(tree_noise_1):get2d({x=math.floor((minp.x + 32) / 160) * 80, y=math.floor((minp.z + 32) / 160) * 80})
-	if minp.y < -112 or minp.y > 208 or (not fun_caves.DEBUG and tree_n < 1) then
+	if not tree_n or minp.y < -112 or minp.y > 208 or (not fun_caves.DEBUG and tree_n < 1) then
 		return
 	end
 
@@ -315,6 +323,9 @@ fun_caves.treegen = function(minp, maxp, data, p2data, area, node)
 	local map_min = {x = minp.x, y = minp.y - 1, z = minp.z}
 
 	local wood_1 = minetest.get_perlin_map(wood_noise, map_max):get3dMap_flat(map_min)
+	if not wood_1 then
+		return
+	end
 
 	local write = false
 

village.lua

@@ -29,7 +29,7 @@ if mobs and mobs.mod == "redo" then
 		end
 	end
 	local function savage_gathering(self)
-		if not fun_caves.custom_ready(self) then
+		if not (self and fun_caves.custom_ready(self)) then
 			return
 		end
 
@@ -45,7 +45,10 @@ if mobs and mobs.mod == "redo" then
 				local p = soil[math.random(#soil)]
 				p.y = p.y + 1
 				minetest.add_node(p, {name = 'farming:seed_wheat', param2 = 1})
-				minetest.get_node_timer(p):start(math.random(166, 286))
+				local timer = minetest.get_node_timer(p)
+				if timer then
+					timer:start(math.random(166, 286))
+				end
 			end
 		end
 
@@ -115,6 +118,10 @@ end
 
 
 local function build_hut(data, area, node, pos, turf)
+	if not (data and area and node and pos and turf and type(data) == 'table') then
+		return
+	end
+
 	local door = {x = ({2,7})[math.random(2)], z = ({2,7})[math.random(2)]}
 
 	for z = 1, 8 do
@@ -151,6 +158,10 @@ local function build_hut(data, area, node, pos, turf)
 end
 
 fun_caves.village = function(minp, maxp, data, p2data, area, node, biome, heightmap)
+	if not (minp and maxp and data and p2data and area and node and type(data) == 'table' and type(p2data) == 'table') then
+		return
+	end
+
 	if not biome or math.random(10) ~= 1 then
 		return
 	end

wallhammer.lua

@@ -23,34 +23,11 @@ local default_material = {
 		}
 
 local function parti(pos)
-  	minetest.add_particlespawner(25, 0.3,
-		pos, pos,
-		{x=2, y=0.2, z=2}, {x=-2, y=2, z=-2},
-		{x=0, y=-6, z=0}, {x=0, y=-10, z=0},
-		0.2, 1,
-		0.2, 2,
-		true, "wallhammer_parti.png")
-end
-
-local function get_pointed_thing(player, range)
-	local plpos = player:getpos()
-	plpos.y = plpos.y+1.625
-	local dir = player:get_look_dir()
-	local p2 = vector.add(plpos, vector.multiply(dir, range))
-	local _,pos = minetest.line_of_sight(plpos, p2)
 	if not pos then
 		return
 	end
-	local check = minetest.get_node(pos)
+
-	if string.find(check.name, '_foot') then
+	minetest.add_particlespawner(25, 0.3, pos, pos, {x=2, y=0.2, z=2}, {x=-2, y=2, z=-2}, {x=0, y=-6, z=0}, {x=0, y=-10, z=0}, 0.2, 1, 0.2, 2, true, "wallhammer_parti.png")
-		pos = vector.add(pos, dir)
-		print('added')
-	end
-	return {
-		under = vector.round(pos),
-		above = vector.round(vector.subtract(pos, dir)),
-		type = "node"
-	}
 end
 
 minetest.register_tool( "fun_caves:wall_hammer",{
@@ -66,13 +43,23 @@ minetest.register_tool( "fun_caves:wall_hammer",{
 		damage_groups = {fleshy=4},
 	},
 	on_use = function(itemstack, user, pointed_thing)
+		if not (pointed_thing and user and itemstack) then
+			return
+		end
 
 		if pointed_thing.type ~= "node" then
 			return
 		end
 
 		local pos = pointed_thing.under
+		if not pos then
+			return
+		end
+
 		local node = minetest.get_node(pos)
+		if not node then
+			return
+		end
 
 		for i in ipairs (default_material) do
 			local item = default_material [i][1]
@@ -85,7 +72,11 @@ minetest.register_tool( "fun_caves:wall_hammer",{
 			end
 
 			if node.name == item then
-				minetest.set_node(pos,{name = "fun_caves:"..mat.."_foot", param2=minetest.dir_to_facedir(user:get_look_dir())})
+				local node = {
+					name = "fun_caves:"..mat.."_foot",
+					param2=minetest.dir_to_facedir(user:get_look_dir())
+				}
+				minetest.set_node(pos, node)
 				parti(pos)
 			end
 		end

wooden_buckets.lua

@@ -1,61 +1,66 @@
 local function register_liquid_wood(source, itemname, inventory_image, name, groups)
-	if itemname ~= nil then
+	if not (source and itemname and inventory_image and name and type(source) == 'string' and type(itemname) == 'string' and type(inventory_image) == 'string') then
-		if inventory_image then
+		return
-			inventory_image = inventory_image..'^fun_caves_wood_bucket_overlay.png'
-		end
-		minetest.register_craftitem(itemname, {
-			description = name,
-			inventory_image = inventory_image,
-			stack_max = 1,
-			liquids_pointable = true,
-			groups = groups,
-
-			on_place = function(itemstack, user, pointed_thing)
-				-- Must be pointing to node
-				if pointed_thing.type ~= "node" then
-					return
-				end
-
-				local node = minetest.get_node_or_nil(pointed_thing.under)
-				local ndef = node and minetest.registered_nodes[node.name]
-
-				-- Call on_rightclick if the pointed node defines it
-				if ndef and ndef.on_rightclick and
-				   user and not user:get_player_control().sneak then
-					return ndef.on_rightclick(
-						pointed_thing.under,
-						node, user,
-						itemstack)
-				end
-
-				local lpos
-
-				-- Check if pointing to a buildable node
-				if ndef and ndef.buildable_to then
-					-- buildable; replace the node
-					lpos = pointed_thing.under
-				else
-					-- not buildable to; place the liquid above
-					-- check if the node above can be replaced
-					lpos = pointed_thing.above
-					local node = minetest.get_node_or_nil(lpos)
-					local above_ndef = node and minetest.registered_nodes[node.name]
-
-					if not above_ndef or not above_ndef.buildable_to then
-						-- do not remove the bucket with the liquid
-						return itemstack
-					end
-				end
-
-				if minetest.is_protected(lpos, user and user:get_player_name() or "") then
-					return
-				end
-
-				minetest.set_node(lpos, {name = source})
-				return ItemStack("fun_caves:bucket_wood_empty")
-			end
-		})
 	end
+
+	inventory_image = inventory_image..'^fun_caves_wood_bucket_overlay.png'
+	minetest.register_craftitem(itemname, {
+		description = name,
+		inventory_image = inventory_image,
+		stack_max = 1,
+		liquids_pointable = true,
+		groups = groups,
+
+		on_place = function(itemstack, user, pointed_thing)
+			if not (user and pointed_thing) then
+				return
+			end
+
+			-- Must be pointing to node
+			if pointed_thing.type ~= "node" then
+				return
+			end
+
+			local node = minetest.get_node_or_nil(pointed_thing.under)
+			local ndef = node and minetest.registered_nodes[node.name]
+
+			-- Call on_rightclick if the pointed node defines it
+			if ndef and ndef.on_rightclick and
+				user and not user:get_player_control().sneak then
+				return ndef.on_rightclick(pointed_thing.under, node, user, itemstack)
+			end
+
+			local lpos
+
+			-- Check if pointing to a buildable node
+			if ndef and ndef.buildable_to then
+				-- buildable; replace the node
+				lpos = pointed_thing.under
+			else
+				-- not buildable to; place the liquid above
+				-- check if the node above can be replaced
+				lpos = pointed_thing.above
+				local node = minetest.get_node_or_nil(lpos)
+				if not node then
+					return
+				end
+
+				local above_ndef = node and minetest.registered_nodes[node.name]
+
+				if not above_ndef or not above_ndef.buildable_to then
+					-- do not remove the bucket with the liquid
+					return itemstack
+				end
+			end
+
+			if minetest.is_protected(lpos, user and user:get_player_name() or "") then
+				return
+			end
+
+			minetest.set_node(lpos, {name = source})
+			return ItemStack("fun_caves:bucket_wood_empty")
+		end
+	})
 end
 
 for fluid, def in pairs(bucket.liquids) do
@@ -86,11 +91,16 @@ minetest.register_craftitem("fun_caves:bucket_wood_empty", {
 	liquids_pointable = true,
 	on_use = function(itemstack, user, pointed_thing)
 		-- Must be pointing to node
-		if pointed_thing.type ~= "node" then
+		if not (user and pointed_thing and pointed_thing.type == "node") then
 			return
 		end
+
 		-- Check if pointing to a liquid source
 		local node = minetest.get_node(pointed_thing.under)
+		if not node then
+			return
+		end
+
 		local liquiddef = bucket.liquids[node.name]
 		if node.name ~= liquiddef.source then
 			return