better pos arg check for waypoint_compass.make_compass()

init.lua

@@ -440,17 +440,20 @@ minetest.register_craft_predict(waypoint_compass_copy_meta)
 -- owner_name is str
 -- label is str
 -- color is int in range [0,0xFFFFFF]
-local error_val = nil --ItemStack('apple') -- used this for testing with //lua
 local function make_compass(pos, owner_name, label, color)
     local itemstack = ItemStack("waypoint_compass:compass")
     local meta = itemstack:get_meta()
-    if not (pos or {}).x or
-	(type(owner_name) ~= 'string') or
-	(type(label) ~= 'string') then
-	return error_val
-    end
-    if not color or type(color) ~= 'number' or color < 0 or color > 0xFFFFFF then
-	return error_val
+    if not (pos and
+	    tonumber(pos.x) and
+	    tonumber(pos.y) and
+	    tonumber(pos.z) and
+	    type(owner_name) == 'string' and
+	    type(label) == 'string' and
+	    color and
+	    type(color) == "number" and
+	    color >= 0 and
+	    color <= 0xFFFFFF ) then
+	return nil
     end
     set_compass_meta_pos(meta, pos)
     set_compass_meta_owner(meta, owner_name)