Add more debug info

api.lua

@@ -87,7 +87,7 @@ end
 function areas:getNodeOwners(pos)
 	local owners = {}
 	for _, area in pairs(self:getAreasAtPos(pos)) do
-    if area.owner then
+    if area.owner and (area.owner ~= "") then
       table.insert(owners, area.owner)
     end
 	end

interact.lua

@@ -1,3 +1,15 @@
+function dump(o)
+   if type(o) == 'table' then
+      local s = '{ '
+      for k,v in pairs(o) do
+         if type(k) ~= 'number' then k = '"'..k..'"' end
+         s = s .. '['..k..'] = ' .. dump(v) .. ','
+      end
+      return s .. '} '
+   else
+      return tostring(o)
+   end
+end
 
 local old_is_protected = minetest.is_protected
 function minetest.is_protected(pos, name)
@@ -11,13 +23,13 @@ minetest.register_on_protection_violation(function(pos, name)
 	if not areas:canInteract(pos, name) then
 		local owners = areas:getNodeOwners(pos)
 
-    print(owners)
+    print(dump(owners))
 
-    if not owners then
+    if not owners[1] then
       owners = areas:getNodeOwnerGroups(pos)
     end
 
-    print(owners)
+    print(dump(owners))
 
     if not owners then
       owners = {}