Add .luacheckrc and fix warnings.

.luacheckrc

@@ -0,0 +1,14 @@
+
+unused_args = false
+allow_defined_top = true
+
+read_globals = {
+	"minetest",
+}
+
+exclude_files = {
+	"irc/*",
+}
+
+globals = {
+}

botcmds.lua

@@ -40,7 +40,7 @@ function irc:bot_command(msg, text)
 	-- Remove leading whitespace
 	text = text:match("^%s*(.*)")
 	if text:sub(1, 1) == "@" then
-		local found, _, player_to, message = text:find("^.([^%s]+)%s(.+)$")
+		local _, _, player_to, message = text:find("^.([^%s]+)%s(.+)$")
 		if not minetest.get_player_by_name(player_to) then
 			irc:reply("User '"..player_to.."' is not in the game.")
 			return
@@ -69,7 +69,7 @@ function irc:bot_command(msg, text)
 		return
 	end
 
-	local success, message = self.bot_commands[cmd].func(msg.user, args)
+	local _, message = self.bot_commands[cmd].func(msg.user, args)
 	if message then
 		self:reply(message)
 	end

chatcmds.lua

@@ -76,8 +76,8 @@ minetest.register_chatcommand("irc_disconnect", {
 		if not irc.connected then
 			return false, "Not connected to IRC. Use /irc_connect to connect."
 		end
-		if params == "" then
-			params = "Manual disconnect by "..name
+		if param == "" then
+			param = "Manual disconnect by "..name
 		end
 		irc:disconnect(param)
 	end
@@ -113,6 +113,7 @@ minetest.register_chatcommand("irc_quote", {
 
 
 local oldme = minetest.chatcommands["me"].func
+-- luacheck: ignore
 minetest.chatcommands["me"].func = function(name, param, ...)
 	irc:say(("* %s %s"):format(name, param))
 	return oldme(name, param, ...)

init.lua

@@ -52,7 +52,7 @@ irc = {
 }
 
 -- Compatibility
-mt_irc = irc
+rawset(_G, "mt_irc", irc)
 
 dofile(modpath.."/config.lua")
 dofile(modpath.."/messages.lua")
@@ -113,7 +113,7 @@ function irc:connect()
 
 	-- We need to swap the `require` function again since
 	-- LuaIRC `require`s `ssl` if `irc.secure` is true.
-	local old_require = require
+	old_require = require
 	require = ie.require
 
 	local good, message = pcall(function()

player_part.lua

@@ -40,9 +40,9 @@ minetest.register_chatcommand("who", {
 	privs = {},
 	func = function(name, param)
 		local out, n = { }, 0
-		for name in pairs(irc.joined_players) do
+		for plname in pairs(irc.joined_players) do
 			n = n + 1
-			out[n] = name
+			out[n] = plname
 		end
 		table.sort(out)
 		return true, "Players in channel: "..table.concat(out, ", ")