From 32c44e00c4b4f7348a63975c87dff06ddf75e592 Mon Sep 17 00:00:00 2001
From: MoNTE48 <MoNTE48@mail.ua>
Date: Wed, 16 Oct 2019 20:08:12 +0200
Subject: [PATCH] Builtin: Clearing Functions and Variables

---
 builtin/async/init.lua                     |  2 +-
 builtin/client/chatcommands.lua            |  6 +++---
 builtin/client/init.lua                    |  2 +-
 builtin/common/async_event.lua             |  2 +-
 builtin/common/filterlist.lua              | 14 ++++++------
 builtin/fstk/ui.lua                        | 10 ++++-----
 builtin/game/chatcommands.lua              | 22 +++++++++----------
 builtin/game/falling.lua                   |  6 +++---
 builtin/game/hunger.lua                    |  8 +++----
 builtin/game/item.lua                      |  8 +++----
 builtin/game/item_entity.lua               |  4 ++--
 builtin/game/misc.lua                      |  8 +++----
 builtin/game/register.lua                  |  8 +++----
 builtin/mainmenu/common.lua                |  6 +++---
 builtin/mainmenu/dlg_config_world.lua      |  4 ++--
 builtin/mainmenu/dlg_create_world.lua      |  9 ++++----
 builtin/mainmenu/dlg_settings_advanced.lua |  2 +-
 builtin/mainmenu/init.lua                  |  2 +-
 builtin/mainmenu/modmgr.lua                | 14 ++++++------
 builtin/mainmenu/tab_credits.lua           |  2 +-
 builtin/mainmenu/tab_local.lua             | 25 +++++-----------------
 builtin/mainmenu/tab_mods.lua              | 12 +++++------
 builtin/mainmenu/tab_online.lua            |  8 +++----
 builtin/mainmenu/tab_server.lua            |  9 ++++----
 builtin/mainmenu/tab_settings.lua          |  5 ++---
 builtin/mainmenu/tab_texturepacks.lua      |  6 +++---
 builtin/profiler/init.lua                  |  2 +-
 builtin/profiler/sampling.lua              |  2 +-
 28 files changed, 93 insertions(+), 115 deletions(-)

diff --git a/builtin/async/init.lua b/builtin/async/init.lua
index 75d70134..7fe54f58 100644
--- a/builtin/async/init.lua
+++ b/builtin/async/init.lua
@@ -4,7 +4,7 @@ core.log("info", "Initializing Asynchronous environment")
 function core.job_processor(serialized_func, serialized_param)
 	local func = loadstring(serialized_func)
 	local param = core.deserialize(serialized_param)
-	local retval = nil
+	local retval
 
 	if type(func) == "function" then
 		retval = core.serialize(func(param))
diff --git a/builtin/client/chatcommands.lua b/builtin/client/chatcommands.lua
index 2b8cc4ac..59881402 100644
--- a/builtin/client/chatcommands.lua
+++ b/builtin/client/chatcommands.lua
@@ -39,7 +39,7 @@ end)
 
 core.register_chatcommand("list_players", {
 	description = core.gettext("List online players"),
-	func = function(param)
+	func = function()
 		local players = table.concat(core.get_player_names(), ", ")
 		core.display_chat_message(core.gettext("Online players: ") .. players)
 	end
@@ -47,14 +47,14 @@ core.register_chatcommand("list_players", {
 
 core.register_chatcommand("disconnect", {
 	description = core.gettext("Exit to main menu"),
-	func = function(param)
+	func = function()
 		core.disconnect()
 	end,
 })
 
 core.register_chatcommand("clear_chat_queue", {
 	description = core.gettext("Clear the out chat queue"),
-	func = function(param)
+	func = function()
 		core.clear_out_chat_queue()
 		return true, core.gettext("The out chat queue is now empty")
 	end,
diff --git a/builtin/client/init.lua b/builtin/client/init.lua
index 5cdbe3e0..72611133 100644
--- a/builtin/client/init.lua
+++ b/builtin/client/init.lua
@@ -16,7 +16,7 @@ core.register_on_death(function()
 	core.show_formspec("bultin:death", formspec)
 end)
 
-core.register_on_formspec_input(function(formname, fields)
+core.register_on_formspec_input(function(formname)
 	if formname == "bultin:death" then
 		core.send_respawn()
 	end
diff --git a/builtin/common/async_event.lua b/builtin/common/async_event.lua
index 2e0f4237..f2a70c46 100644
--- a/builtin/common/async_event.lua
+++ b/builtin/common/async_event.lua
@@ -9,7 +9,7 @@ end
 
 if core.register_globalstep then
 	core.register_globalstep(function(dtime)
-		for i, job in ipairs(core.get_finished_jobs()) do
+		for _, job in ipairs(core.get_finished_jobs()) do
 			handle_job(job.jobid, job.retval)
 		end
 	end)
diff --git a/builtin/common/filterlist.lua b/builtin/common/filterlist.lua
index 66a54e1e..58bd26ab 100644
--- a/builtin/common/filterlist.lua
+++ b/builtin/common/filterlist.lua
@@ -146,7 +146,7 @@ function filterlist.get_raw_index(self,listindex)
 
 		for i,v in ipairs(self.m_raw_list) do
 
-			if self.m_compare_fct(v,entry) then
+			if self.m_compare_fct(v, entry) then
 				return i
 			end
 		end
@@ -165,7 +165,7 @@ function filterlist.get_current_index(self,listindex)
 
 		for i,v in ipairs(self.m_processed_list) do
 
-			if self.m_compare_fct(v,entry) then
+			if self.m_compare_fct(v, entry) then
 				return i
 			end
 		end
@@ -186,9 +186,9 @@ function filterlist.process(self)
 
 	self.m_processed_list = {}
 
-	for k,v in pairs(self.m_raw_list) do
+	for _, v in pairs(self.m_raw_list) do
 		if self.m_filtercriteria == nil or
-			self.m_filter_fct(v,self.m_filtercriteria) then
+			self.m_filter_fct(v, self.m_filtercriteria) then
 			self.m_processed_list[#self.m_processed_list + 1] = v
 		end
 	end
@@ -215,8 +215,8 @@ end
 
 --------------------------------------------------------------------------------
 function filterlist.uid_exists_raw(self,uid)
-	for i,v in ipairs(self.m_raw_list) do
-		if self.m_uid_match_fct(v,uid) then
+	for _, v in ipairs(self.m_raw_list) do
+		if self.m_uid_match_fct(v, uid) then
 			return true
 		end
 	end
@@ -228,7 +228,7 @@ function filterlist.raw_index_by_uid(self, uid)
 	local elementcount = 0
 	local elementidx = 0
 	for i,v in ipairs(self.m_raw_list) do
-		if self.m_uid_match_fct(v,uid) then
+		if self.m_uid_match_fct(v, uid) then
 			elementcount = elementcount +1
 			elementidx = i
 		end
diff --git a/builtin/fstk/ui.lua b/builtin/fstk/ui.lua
index f6b70e4d..9cb7e567 100644
--- a/builtin/fstk/ui.lua
+++ b/builtin/fstk/ui.lua
@@ -128,7 +128,7 @@ function ui.update()
 				restart_btn
 	else
 		local active_toplevel_ui_elements = 0
-		for key,value in pairs(ui.childlist) do
+		for _, value in pairs(ui.childlist) do
 			if (value.type == "toplevel") then
 				local retval = value:get_formspec()
 
@@ -141,7 +141,7 @@ function ui.update()
 
 		-- no need to show addons if there ain't a toplevel element
 		if (active_toplevel_ui_elements > 0) then
-			for key,value in pairs(ui.childlist) do
+			for _, value in pairs(ui.childlist) do
 				if (value.type == "addon") then
 					local retval = value:get_formspec()
 
@@ -169,8 +169,7 @@ end
 
 --------------------------------------------------------------------------------
 function ui.handle_buttons(fields)
-	for key,value in pairs(ui.childlist) do
-
+	for _, value in pairs(ui.childlist) do
 		local retval = value:handle_buttons(fields)
 
 		if retval then
@@ -184,8 +183,7 @@ end
 --------------------------------------------------------------------------------
 function ui.handle_events(event)
 
-	for key,value in pairs(ui.childlist) do
-
+	for _, value in pairs(ui.childlist) do
 		if value.handle_events ~= nil then
 			local retval = value:handle_events(event)
 
diff --git a/builtin/game/chatcommands.lua b/builtin/game/chatcommands.lua
index a386fc87..18f295f7 100644
--- a/builtin/game/chatcommands.lua
+++ b/builtin/game/chatcommands.lua
@@ -340,7 +340,7 @@ core.register_chatcommand("teleport", {
 			return pos, false
 		end
 
-		local teleportee = nil
+		local teleportee
 		local p = {}
 		p.x, p.y, p.z = string.match(param, "^([%d.-]+)[, ] *([%d.-]+)[, ] *([%d.-]+)$")
 		p.x = tonumber(p.x)
@@ -358,9 +358,9 @@ core.register_chatcommand("teleport", {
 			end
 		end
 
-		local teleportee = nil
-		local p = nil
-		local target_name = nil
+		local teleportee
+		local p
+		local target_name
 		target_name = param:match("^([^ ]+)$")
 		teleportee = core.get_player_by_name(name)
 		if target_name then
@@ -380,9 +380,9 @@ core.register_chatcommand("teleport", {
 			return false, "You don't have permission to teleport other players (missing bring privilege)"
 		end
 
-		local teleportee = nil
+		local teleportee
 		local p = {}
-		local teleportee_name = nil
+		local teleportee_name
 		teleportee_name, p.x, p.y, p.z = param:match(
 				"^([^ ]+) +([%d.-]+)[, ] *([%d.-]+)[, ] *([%d.-]+)$")
 		p.x, p.y, p.z = tonumber(p.x), tonumber(p.y), tonumber(p.z)
@@ -395,10 +395,10 @@ core.register_chatcommand("teleport", {
 					.. " to " .. core.pos_to_string(vector.round(p))
 		end
 
-		local teleportee = nil
-		local p = nil
-		local teleportee_name = nil
-		local target_name = nil
+		local teleportee
+		local p
+		local teleportee_name
+		local target_name
 		teleportee_name, target_name = string.match(param, "^([^ ]+) +([^ ]+)$")
 		if teleportee_name then
 			teleportee = core.get_player_by_name(teleportee_name)
@@ -749,7 +749,7 @@ core.register_chatcommand("rollback", {
 		end
 		local target_name, seconds = string.match(param, ":([^ ]+) *(%d*)")
 		if not target_name then
-			local player_name = nil
+			local player_name
 			player_name, seconds = string.match(param, "([^ ]+) *(%d*)")
 			if not player_name then
 				return false, "Invalid parameters. See /help rollback"
diff --git a/builtin/game/falling.lua b/builtin/game/falling.lua
index 053153f6..96e39c2a 100644
--- a/builtin/game/falling.lua
+++ b/builtin/game/falling.lua
@@ -318,17 +318,17 @@ end
 -- Global callbacks
 --
 
-local function on_placenode(p, node)
+local function on_placenode(p)
 	core.check_for_falling(p)
 end
 core.register_on_placenode(on_placenode)
 
-local function on_dignode(p, node)
+local function on_dignode(p)
 	core.check_for_falling(p)
 end
 core.register_on_dignode(on_dignode)
 
-local function on_punchnode(p, node)
+local function on_punchnode(p)
 	core.check_for_falling(p)
 end
 core.register_on_punchnode(on_punchnode)
diff --git a/builtin/game/hunger.lua b/builtin/game/hunger.lua
index f7b8e0be..d0a45c86 100644
--- a/builtin/game/hunger.lua
+++ b/builtin/game/hunger.lua
@@ -371,16 +371,16 @@ end)
 
 core.register_globalstep(hunger_globaltimer)
 
-core.register_on_placenode(function(pos, oldnode, player, ext)
+core.register_on_placenode(function(_, _, player)
 	hunger.exhaust_player(player, settings.exhaust_place, hunger.exhaustion_reasons.place)
 end)
-core.register_on_dignode(function(pos, oldnode, player, ext)
+core.register_on_dignode(function(_, _, player)
 	hunger.exhaust_player(player, settings.exhaust_dig, hunger.exhaustion_reasons.dig)
 end)
-core.register_on_craft(function(itemstack, player, old_craft_grid, craft_inv)
+core.register_on_craft(function(_, player)
 	hunger.exhaust_player(player, settings.exhaust_craft, hunger.exhaustion_reasons.craft)
 end)
-core.register_on_punchplayer(function(player, hitter, time_from_last_punch, tool_capabilities, dir, damage)
+core.register_on_punchplayer(function(_, hitter)
 	hunger.exhaust_player(hitter, settings.exhaust_punch, hunger.exhaustion_reasons.punch)
 end)
 core.register_on_respawnplayer(function(player)
diff --git a/builtin/game/item.lua b/builtin/game/item.lua
index fc032901..b010fc08 100644
--- a/builtin/game/item.lua
+++ b/builtin/game/item.lua
@@ -347,7 +347,7 @@ function core.item_place_node(itemstack, placer, pointed_thing, param2,
 
 	-- Transfer color information
 	if metatable.palette_index and not def.place_param2 then
-		local color_divisor = nil
+		local color_divisor
 		if def.paramtype2 == "color" then
 			color_divisor = 1
 		elseif def.paramtype2 == "colorwallmounted" then
@@ -449,7 +449,7 @@ local function item_throw_step(entity, dtime)
 		entity.object:remove()
 		return
 	end
-	local hit_object = nil
+	local hit_object
 	local dir = vector.normalize(entity.object:get_velocity())
 	local pos2 = vector.add(pos, vector.multiply(dir, 3))
 	local _, node_pos = minetest.line_of_sight(pos, pos2)
@@ -490,7 +490,7 @@ function core.item_throw(name, thrower, speed, accel, on_impact)
 		return
 	end
 	pos.y = pos.y + 1.5
-	local obj = nil
+	local obj
 	local properties = {is_visible=true}
 	if core.registered_entities[name] then
 		obj = core.add_entity(pos, name)
@@ -674,7 +674,7 @@ function core.node_dig(pos, node, digger)
 	-- Handle drops
 	core.handle_node_drops(pos, drops, digger)
 
-	local oldmetadata = nil
+	local oldmetadata
 	if def and def.after_dig_node then
 		oldmetadata = core.get_meta(pos):to_table()
 	end
diff --git a/builtin/game/item_entity.lua b/builtin/game/item_entity.lua
index a7460322..e6499f9e 100644
--- a/builtin/game/item_entity.lua
+++ b/builtin/game/item_entity.lua
@@ -306,7 +306,7 @@ core.register_entity(":__builtin:item", {
 			return
 		end
 		local objects = core.get_objects_inside_radius(pos, 0.25)
-		for k, obj in pairs(objects) do
+		for _, obj in pairs(objects) do
 			local entity = obj:get_luaentity()
 			if entity and entity.name == "__builtin:item" then
 				if self:try_merge_with(own_stack, obj, entity) then
@@ -342,7 +342,7 @@ local function collect_items(player)
 	-- Detect
 	local col_pos = vector.add(pos, {x = 0, y = 1.3, z = 0})
 	local objects = core.get_objects_inside_radius(col_pos, 2)
-	for k, obj in pairs(objects) do
+	for _, obj in pairs(objects) do
 		local entity = obj:get_luaentity()
 		if entity and entity.name == "__builtin:item" and
 				not entity.collectioner and entity.age > 0.5 then
diff --git a/builtin/game/misc.lua b/builtin/game/misc.lua
index 1ce7d6b9..19ca9a02 100644
--- a/builtin/game/misc.lua
+++ b/builtin/game/misc.lua
@@ -25,7 +25,7 @@ function core.check_player_privs(name, ...)
 		end
 	else
 		-- Only a list, we can process it directly.
-		for key, priv in pairs(requested_privs) do
+		for _, priv in pairs(requested_privs) do
 			if not player_privs[priv] then
 				missing_privileges[#missing_privileges + 1] = priv
 			end
@@ -61,7 +61,7 @@ end)
 
 function core.get_connected_players()
 	local temp_table = {}
-	for index, value in pairs(player_list) do
+	for _, value in pairs(player_list) do
 		if value:is_player_connected() then
 			temp_table[#temp_table + 1] = value
 		end
@@ -150,12 +150,12 @@ function core.setting_get_pos(name)
 end
 
 -- To be overriden by protection mods
-function core.is_protected(pos, name)
+function core.is_protected()
 	return false
 end
 
 -- To be overriden by protection mods
-function core.is_protected_action(pos, name)
+function core.is_protected_action()
 	return false
 end
 
diff --git a/builtin/game/register.lua b/builtin/game/register.lua
index eb162e33..406fd9b1 100644
--- a/builtin/game/register.lua
+++ b/builtin/game/register.lua
@@ -419,7 +419,7 @@ function core.run_callbacks(callbacks, mode, ...)
 			return false
 		end
 	end
-	local ret = nil
+	local ret
 	for i = 1, cb_len do
 		local origin = core.callback_origins[callbacks[i]]
 		if origin then
@@ -579,9 +579,9 @@ core.registered_on_punchplayers, core.register_on_punchplayer = make_registratio
 players_per_step = core.settings:get("players_per_globalstep")
 players_per_step = players_per_step and tonumber(players_per_step) or 20
 
-local player_iter = nil
-local player_iter_forced = nil
-local playerstep_iter = nil
+local player_iter
+local player_iter_forced
+local playerstep_iter
 local playerstep_funcs = {}
 local playerstep_funcs_forced = {}
 local playernames = {}
diff --git a/builtin/mainmenu/common.lua b/builtin/mainmenu/common.lua
index 52ce10a7..836f694c 100644
--- a/builtin/mainmenu/common.lua
+++ b/builtin/mainmenu/common.lua
@@ -51,7 +51,7 @@ local function configure_selected_world_params(idx)
 end
 
 --------------------------------------------------------------------------------
-function image_column(tooltip, flagname)
+function image_column(tooltip)
 	return "image,tooltip=" .. core.formspec_escape(tooltip) .. "," ..
 		"0=" .. core.formspec_escape(defaulttexturedir .. "blank.png") .. "," ..
 		"1=" .. core.formspec_escape(defaulttexturedir .. "server_flags_favorite.png") .. "," ..
@@ -189,7 +189,7 @@ function menu_render_worldlist()
 	local retval = ""
 	local current_worldlist = menudata.worldlist:get_list()
 
-	for i, v in ipairs(current_worldlist) do
+	for _, v in ipairs(current_worldlist) do
 		if retval ~= "" then retval = retval .. "," end
 		retval = retval .. core.formspec_escape(v.name) .. ""
 	end
@@ -232,7 +232,7 @@ function asyncOnlineFavourites()
 	end
 
 	core.handle_async(
-		function(param)
+		function()
 			return core.get_favorites("online")
 		end,
 		nil,
diff --git a/builtin/mainmenu/dlg_config_world.lua b/builtin/mainmenu/dlg_config_world.lua
index b0524fff..7badd7fd 100644
--- a/builtin/mainmenu/dlg_config_world.lua
+++ b/builtin/mainmenu/dlg_config_world.lua
@@ -160,7 +160,7 @@ local function handle_buttons(this, fields)
 		local rawlist = this.data.list:get_raw_list()
 
 		local i,mod
-		for i,mod in ipairs(rawlist) do
+		for _, mod in ipairs(rawlist) do
 			if not mod.is_modpack and
 					not mod.is_game_content then
 				if modname_valid(mod.name) then
@@ -175,7 +175,7 @@ local function handle_buttons(this, fields)
 		end
 
 		-- Remove mods that are not present anymore
-		for key,value in pairs(mods) do
+		for key, _ in pairs(mods) do
 			if key:sub(1,9) == "load_mod_" then
 				worldfile:remove(key)
 			end
diff --git a/builtin/mainmenu/dlg_create_world.lua b/builtin/mainmenu/dlg_create_world.lua
index 467eb149..eb7444ca 100644
--- a/builtin/mainmenu/dlg_create_world.lua
+++ b/builtin/mainmenu/dlg_create_world.lua
@@ -15,7 +15,7 @@
 --with this program; if not, write to the Free Software Foundation, Inc.,
 --51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 
-local function create_world_formspec(dialogdata)
+local function create_world_formspec()
 	local mapgens = core.get_mapgen_names()
 	local current_seed = core.settings:get("fixed_map_seed") or ""
 	local current_mg   = core.settings:get("mg_name")
@@ -23,7 +23,7 @@ local function create_world_formspec(dialogdata)
 	local mglist = ""
 	local selindex = 1
 	local i = 1
-	for k,v in pairs(mapgens) do
+	for _, v in pairs(mapgens) do
 		if current_mg == v then
 			selindex = i
 		end
@@ -34,9 +34,8 @@ local function create_world_formspec(dialogdata)
 
 	local gameid = core.settings:get("menu_last_game")
 
-	local game, gameidx = nil , 0
 	if gameid ~= nil then
-		game, gameidx = gamemgr.find_by_gameid(gameid)
+		local gameidx = gamemgr.find_by_gameid(gameid)
 
 		if gameidx == nil then
 			gameidx = 0
@@ -87,7 +86,7 @@ local function create_world_buttonhandler(this, fields)
 		if gameindex ~= nil and
 			worldname ~= "" then
 
-			local message = nil
+			local message
 
 			core.settings:set("fixed_map_seed", fields["te_seed"])
 
diff --git a/builtin/mainmenu/dlg_settings_advanced.lua b/builtin/mainmenu/dlg_settings_advanced.lua
index 95ac6d6c..550cd867 100644
--- a/builtin/mainmenu/dlg_settings_advanced.lua
+++ b/builtin/mainmenu/dlg_settings_advanced.lua
@@ -358,7 +358,7 @@ local function filter_settings(settings, searchstring)
 	local result = {}
 	local category_stack = {}
 	local current_level = 0
-	local best_setting = nil
+	local best_setting
 	for _, entry in pairs(settings) do
 		if entry.type == "category" then
 			-- Remove all settingless categories
diff --git a/builtin/mainmenu/init.lua b/builtin/mainmenu/init.lua
index 4b46a204..460c7f03 100644
--- a/builtin/mainmenu/init.lua
+++ b/builtin/mainmenu/init.lua
@@ -61,7 +61,7 @@ if not use_simple_menu then
 end
 
 --------------------------------------------------------------------------------
-local function main_event_handler(tabview, event)
+local function main_event_handler(_, event)
 	if event == "MenuQuit" then
 		core.close()
 	end
diff --git a/builtin/mainmenu/modmgr.lua b/builtin/mainmenu/modmgr.lua
index 9c8076f4..6aa3df19 100644
--- a/builtin/mainmenu/modmgr.lua
+++ b/builtin/mainmenu/modmgr.lua
@@ -142,7 +142,7 @@ end
 --------------------------------------------------------------------------------
 function modmgr.parse_register_line(line)
 	local pos1 = line:find("\"")
-	local pos2 = nil
+	local pos2
 	if pos1 ~= nil then
 		pos2 = line:find("\"",pos1+1)
 	end
@@ -169,7 +169,7 @@ end
 --------------------------------------------------------------------------------
 function modmgr.parse_dofile_line(modpath,line)
 	local pos1 = line:find("\"")
-	local pos2 = nil
+	local pos2
 	if pos1 ~= nil then
 		pos2 = line:find("\"",pos1+1)
 	end
@@ -193,7 +193,7 @@ function modmgr.identify_modname(modpath,filename)
 		local line = testfile:read()
 
 		while line~= nil do
-			local modname = nil
+			local modname
 
 			if line:find("minetest.register_tool") then
 				modname = modmgr.parse_register_line(line)
@@ -226,8 +226,6 @@ function modmgr.identify_modname(modpath,filename)
 end
 --------------------------------------------------------------------------------
 function modmgr.render_modlist(render_list)
-	local retval = ""
-
 	if render_list == nil then
 		if modmgr.global_mods == nil then
 			modmgr.refresh_globals()
@@ -236,7 +234,7 @@ function modmgr.render_modlist(render_list)
 	end
 
 	local list = render_list:get_list()
-	local last_modpack = nil
+	local last_modpack
 	local retval = {}
 	for i, v in ipairs(list) do
 		local color = ""
@@ -343,7 +341,7 @@ function modmgr.installmod(modfilename,basename)
 	local basefolder = modmgr.getbasefolder(modpath)
 
 	if basefolder.type == "modpack" then
-		local clean_path = nil
+		local clean_path
 
 		if basename ~= nil then
 			clean_path = "mp_" .. basename
@@ -441,7 +439,7 @@ function modmgr.preparemodlist(data)
 	for key,value in pairs(worldfile:to_table()) do
 		if key:sub(1, 9) == "load_mod_" then
 			key = key:sub(10)
-			local element = nil
+			local element
 			for i=1,#retval,1 do
 				if retval[i].name == key and
 					not retval[i].is_modpack then
diff --git a/builtin/mainmenu/tab_credits.lua b/builtin/mainmenu/tab_credits.lua
index 54083b93..bea1b94f 100644
--- a/builtin/mainmenu/tab_credits.lua
+++ b/builtin/mainmenu/tab_credits.lua
@@ -94,7 +94,7 @@ end
 return {
 	name = "credits",
 	caption = fgettext("Credits"),
-	cbf_formspec = function(tabview, name, tabdata)
+	cbf_formspec = function()
 	local version = core.get_version()
 		return "label[0.1,-0.1;MultiCraft Open Source Project, ver. " .. version.string .. "]" ..
 			"label[0.1,0.3;Copyright (C) 2014-2019 MultiCraft Development Team]" ..
diff --git a/builtin/mainmenu/tab_local.lua b/builtin/mainmenu/tab_local.lua
index e6170cf3..9c46dc3c 100644
--- a/builtin/mainmenu/tab_local.lua
+++ b/builtin/mainmenu/tab_local.lua
@@ -15,22 +15,11 @@
 --with this program; if not, write to the Free Software Foundation, Inc.,
 --51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 
-local function current_game()
-	local last_game_id = core.settings:get("menu_last_game")
-	local game, index = gamemgr.find_by_gameid(last_game_id)
-
-	return game
-end
-
-
-local function get_formspec(tabview, name, tabdata)
-	local retval = ""
-
+local function get_formspec()
 	local index = filterlist.get_current_index(menudata.worldlist,
-				tonumber(core.settings:get("mainmenu_last_selected_world"))
-				)
+				tonumber(core.settings:get("mainmenu_last_selected_world")))
 
-		retval = retval ..
+	local retval =
 			"image_button[0,4.84;3.31,0.92;" ..
 				core.formspec_escape(defaulttexturedir ..
 					"blank.png") .. ";world_delete;;true;false]" ..
@@ -53,7 +42,7 @@ local function get_formspec(tabview, name, tabdata)
 	return retval
 end
 
-local function main_button_handler(this, fields, name, tabdata)
+local function main_button_handler(this, fields, name)
 	assert(name == "local")
 
 	local world_doubleclick = false
@@ -122,7 +111,7 @@ local function main_button_handler(this, fields, name, tabdata)
 				--update last game
 				local world = menudata.worldlist:get_raw_element(gamedata.selected_world)
 				if world then
-					local game, index = gamemgr.find_by_gameid(world.gameid)
+					local game = gamemgr.find_by_gameid(world.gameid)
 					core.settings:set("menu_last_game", game.id)
 				end
 
@@ -190,14 +179,10 @@ local function main_button_handler(this, fields, name, tabdata)
 	end
 end
 
-local function on_change(type, old_tab, new_tab)
-end
-
 --------------------------------------------------------------------------------
 return {
 	name = "local",
 	caption = fgettext("Singleplayer"),
 	cbf_formspec = get_formspec,
 	cbf_button_handler = main_button_handler,
-	on_change = on_change
 }
diff --git a/builtin/mainmenu/tab_mods.lua b/builtin/mainmenu/tab_mods.lua
index 1be6bd79..661ebbed 100644
--- a/builtin/mainmenu/tab_mods.lua
+++ b/builtin/mainmenu/tab_mods.lua
@@ -16,7 +16,7 @@
 --51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 
 --------------------------------------------------------------------------------
-local function get_formspec(tabview, name, tabdata)
+local function get_formspec(_, _, tabdata)
 
 	if modmgr.global_mods == nil then
 		modmgr.refresh_globals()
@@ -42,18 +42,18 @@ local function get_formspec(tabview, name, tabdata)
 --		"button[0,4.85;5.25,0.5;btn_modstore;".. fgettext("Online mod repository") .. "]"
 		""
 
-	local selected_mod = nil
+	local selected_mod
 
 	if filterlist.size(modmgr.global_mods) >= tabdata.selected_mod then
 		selected_mod = modmgr.global_mods:get_list()[tabdata.selected_mod]
 	end
 
 	if selected_mod ~= nil then
-		local modscreenshot = nil
+		local modscreenshot
 
 		--check for screenshot beeing available
 		local screenshotfilename = selected_mod.path .. DIR_DELIM .. "screenshot.png"
-		local error = nil
+		local error
 		local screenshotfile,error = io.open(screenshotfilename,"r")
 		if error == nil then
 			screenshotfile:close()
@@ -68,7 +68,7 @@ local function get_formspec(tabview, name, tabdata)
 				.. "image[5.5,0;3,2;" .. core.formspec_escape(modscreenshot) .. "]"
 				.. "label[8.25,0.6;" .. selected_mod.name .. "]"
 
-		local descriptionlines = nil
+		local descriptionlines
 		error = nil
 		local descriptionfilename = selected_mod.path .. "description.txt"
 		local descriptionfile,error = io.open(descriptionfilename,"r")
@@ -126,7 +126,7 @@ local function get_formspec(tabview, name, tabdata)
 end
 
 --------------------------------------------------------------------------------
-local function handle_buttons(tabview, fields, tabname, tabdata)
+local function handle_buttons(tabview, fields, _, tabdata)
 	if fields["modlist"] ~= nil then
 		local event = core.explode_table_event(fields["modlist"])
 		tabdata.selected_mod = event.row
diff --git a/builtin/mainmenu/tab_online.lua b/builtin/mainmenu/tab_online.lua
index 4c52a9ca..4b236944 100644
--- a/builtin/mainmenu/tab_online.lua
+++ b/builtin/mainmenu/tab_online.lua
@@ -16,11 +16,11 @@
 --51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 
 --------------------------------------------------------------------------------
-local function get_formspec(tabview, name, tabdata)
+local function get_formspec(_, _, tabdata)
 	-- Update the cached supported proto info,
 	-- it may have changed after a change by the settings menu.
 	common_update_cached_supp_proto()
-	local fav_selected = nil
+	local fav_selected
 	if menudata.search_result then
 		fav_selected = menudata.search_result[tabdata.fav_selected]
 	else
@@ -139,7 +139,7 @@ local function get_formspec(tabview, name, tabdata)
 end
 
 --------------------------------------------------------------------------------
-local function main_button_handler(tabview, fields, name, tabdata)
+local function main_button_handler(_, fields, _, tabdata)
 	local serverlist = menudata.search_result or menudata.favorites
 
 	if fields.te_name then
@@ -360,7 +360,7 @@ local function main_button_handler(tabview, fields, name, tabdata)
 	return false
 end
 
-local function on_change(type, old_tab, new_tab)
+local function on_change(type)
 	if type == "LEAVE" then return end
 	asyncOnlineFavourites()
 end
diff --git a/builtin/mainmenu/tab_server.lua b/builtin/mainmenu/tab_server.lua
index 005b4989..bb7b5875 100644
--- a/builtin/mainmenu/tab_server.lua
+++ b/builtin/mainmenu/tab_server.lua
@@ -16,11 +16,10 @@
 --51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 
 --------------------------------------------------------------------------------
-local function get_formspec(tabview, name, tabdata)
+local function get_formspec()
 
 	local index = menudata.worldlist:get_current_index(
-				tonumber(core.setting_get("mainmenu_last_selected_world"))
-				)
+				tonumber(core.setting_get("mainmenu_last_selected_world")))
 
 	local retval =
 		"button[4,4.15;2.6,0.5;world_delete;" .. fgettext("Delete") .. "]" ..
@@ -66,7 +65,7 @@ local function get_formspec(tabview, name, tabdata)
 end
 
 --------------------------------------------------------------------------------
-local function main_button_handler(this, fields, name, tabdata)
+local function main_button_handler(this, fields)
 
 	local world_doubleclick = false
 
@@ -133,7 +132,7 @@ local function main_button_handler(this, fields, name, tabdata)
 			--update last game
 			local world = menudata.worldlist:get_raw_element(gamedata.selected_world)
 			if world then
-				local game, index = gamemgr.find_by_gameid(world.gameid)
+				local game = gamemgr.find_by_gameid(world.gameid)
 				core.settings:set("menu_last_game", game.id)
 			end
 
diff --git a/builtin/mainmenu/tab_settings.lua b/builtin/mainmenu/tab_settings.lua
index c23cbe4a..a3dfe2fd 100644
--- a/builtin/mainmenu/tab_settings.lua
+++ b/builtin/mainmenu/tab_settings.lua
@@ -122,7 +122,7 @@ local function antialiasing_fname_to_name(fname)
 	return 0
 end
 
-local function formspec(tabview, name, tabdata)
+local function formspec()
 	local tab_string =
 		"box[0,0;3.75,4.5;#999999]" ..
 		"checkbox[0.25,0;cb_smooth_lighting;" .. fgettext("Smooth Lighting") .. ";"
@@ -208,14 +208,13 @@ local function formspec(tabview, name, tabdata)
 end
 
 --------------------------------------------------------------------------------
-local function handle_settings_buttons(this, fields, tabname, tabdata)
+local function handle_settings_buttons(this, fields)
 
 	if fields["btn_advanced_settings"] ~= nil then
 		local adv_settings_dlg = create_adv_settings_dlg()
 		adv_settings_dlg:set_parent(this)
 		this:hide()
 		adv_settings_dlg:show()
-		--mm_texture.update("singleplayer", current_game())
 		return true
 	end
 	if fields["cb_smooth_lighting"] then
diff --git a/builtin/mainmenu/tab_texturepacks.lua b/builtin/mainmenu/tab_texturepacks.lua
index 6af1a079..3d8ed7e9 100644
--- a/builtin/mainmenu/tab_texturepacks.lua
+++ b/builtin/mainmenu/tab_texturepacks.lua
@@ -35,7 +35,7 @@ end
 local function render_texture_pack_list(list)
 	local retval = ""
 
-	for i, v in ipairs(list) do
+	for _, v in ipairs(list) do
 		if v:sub(1, 1) ~= "." then
 			if retval ~= "" then
 				retval = retval .. ","
@@ -49,7 +49,7 @@ local function render_texture_pack_list(list)
 end
 
 --------------------------------------------------------------------------------
-local function get_formspec(tabview, name, tabdata)
+local function get_formspec()
 
 	local retval = "label[4,-0.25;" .. fgettext("Select texture pack:") .. "]" ..
 			"textlist[4,0.25;7.5,5.0;TPs;"
@@ -101,7 +101,7 @@ local function get_formspec(tabview, name, tabdata)
 end
 
 --------------------------------------------------------------------------------
-local function main_button_handler(tabview, fields, name, tabdata)
+local function main_button_handler(_, fields)
 	if fields["TPs"] then
 		local event = core.explode_textlist_event(fields["TPs"])
 		if event.type == "CHG" or event.type == "DCL" then
diff --git a/builtin/profiler/init.lua b/builtin/profiler/init.lua
index e0aaa9bb..1437da8b 100644
--- a/builtin/profiler/init.lua
+++ b/builtin/profiler/init.lua
@@ -45,7 +45,7 @@ function profiler.init_chatcommand()
 		description = "handle the profiler and profiling data",
 		params = param_usage,
 		privs = { server=true },
-		func = function(name, param)
+		func = function(_, param)
 			local command, arg0 = string.match(param, "([^ ]+) ?(.*)")
 			local args = arg0 and string.split(arg0, " ")
 
diff --git a/builtin/profiler/sampling.lua b/builtin/profiler/sampling.lua
index 60b71ba7..dd94d1c4 100644
--- a/builtin/profiler/sampling.lua
+++ b/builtin/profiler/sampling.lua
@@ -140,7 +140,7 @@ end
 -- Like any globalstep function, this should not be too heavy,
 -- but does not add to the instrumentation overhead.
 --
-local function sample(dtime)
+local function sample()
 	-- Rare, but happens and is currently of no informational value.
 	if logged_time == 0 then
 		return