add .luacheckrc, workflow and fix some issues

fixes #1

.github/workflows/luacheck.yml

@@ -0,0 +1,17 @@
+name: luacheck
+
+on: [push, pull_request]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@master
+    - name: apt
+      run: sudo apt-get install -y luarocks
+    - name: luacheck install
+      run: luarocks install --local luacheck
+    - name: luacheck run
+      run: $HOME/.luarocks/bin/luacheck ./

.luacheckrc

@@ -0,0 +1,15 @@
+
+read_globals = {
+	-- Stdlib
+	string = {fields = {"split"}},
+	table = {fields = {"copy", "getn"}},
+	"VoxelManip",
+
+	-- Minetest
+	"minetest", "DIR_DELIM",
+	"vector", "ItemStack",
+	"dump", "VoxelArea",
+
+	-- Deps
+	"dreambuilder_theme"
+}

init.lua

@@ -1,4 +1,8 @@
-local themename = dreambuilder_theme and dreambuilder_theme.name.."_" or ""
+local themename = ""
+
+if minetest.global_exists("dreambuilder_theme") then
+	themename = dreambuilder_theme.name.."_"
+end
 
 local player_hotbar_settings = {}
 local f = io.open(minetest.get_worldpath()..DIR_DELIM.."hotbar_settings","r")
@@ -32,9 +36,9 @@ local function set_hotbar_size(player, s)
 end
 
 minetest.register_on_joinplayer(function(player)
-	minetest.after(0.5,function(hotbar_size)
+	minetest.after(0.5,function()
 		set_hotbar_size(player, tonumber(player_hotbar_settings[player:get_player_name()]) or hotbar_size_default)
-	end, hotbar_size)
+	end)
 end)
 
 minetest.register_chatcommand("hotbar", {
@@ -45,7 +49,7 @@ minetest.register_chatcommand("hotbar", {
 		player_hotbar_settings[name] = size
 		minetest.chat_send_player(name, "[_] Hotbar size set to " ..size.. ".")
 
-		local f = io.open(minetest.get_worldpath()..DIR_DELIM.."hotbar_settings","w")
+		f = io.open(minetest.get_worldpath()..DIR_DELIM.."hotbar_settings","w")
 		if not f then
 			minetest.log("error","Failed to save hotbar settings")
 		else