Add luacheck CI and drop node_ownership remnants (#44)

`node_ownership` is long dead, and pollutes the global namespace. Support dropped after ~7 years.

Co-authored-by: BuckarooBanzay <BuckarooBanzay@users.noreply.github.com>

.github/workflows/luacheck.yml

@@ -0,0 +1,17 @@
+name: luacheck
+
+on: [push, pull_request]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v2
+    - 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

@@ -1,5 +1,4 @@
 unused_args = false
-allow_defined_top = true
 
 read_globals = {
 	"DIR_DELIM",
@@ -10,9 +9,16 @@ read_globals = {
 	"PseudoRandom", "ItemStack",
 	"AreaStore",
 	"default",
+	"factions",
 	table = { fields = { "copy", "getn" } }
 }
 
 globals = {
-	"minetest"
+	"minetest",
+	-- mod namespace
+	"areas"
+}
+
+files["legacy.lua"] = {
+	ignore = {"512"}
 }

legacy.lua

@@ -106,34 +106,3 @@ function areas.hasOwner(pos)
 	end
 	return false
 end
-
-IsPlayerNodeOwner = areas.isNodeOwner
-GetNodeOwnerName  = areas.getNodeOwnerName
-HasOwner          = areas.hasOwner
-
--- This is entirely untested and may break in strange and new ways.
-if areas.config.legacy_table then
-	owner_defs = setmetatable({}, {
-		__index = function(table, key)
-			local a = rawget(areas.areas, key)
-			if not a then return a end
-			local b = {}
-			for k, v in pairs(a) do b[k] = v end
-			b.x1, b.y1, b.z1 = b.pos1.x, b.pos1.y, b.pos1.z
-			b.x2, b.y1, b.z2 = b.pos2.x, b.pos2.y, b.pos2.z
-			b.pos1, b.pos2 = nil, nil
-			b.id = key
-			return b
-		end,
-		__newindex = function(table, key, value)
-			local a = value
-			a.pos1, a.pos2 = {x=a.x1, y=a.y1, z=a.z1},
-					{x=a.x2, y=a.y2, z=a.z2}
-			a.x1, a.y1, a.z1, a.x2, a.y2, a.z2 =
-				nil, nil, nil, nil, nil, nil
-			a.name = a.name or S("unnamed")
-			a.id = nil
-			return rawset(areas.areas, key, a)
-		end
-	})
-end