buying a plot does no longer permit the player to modify other plots

protection.lua

@@ -41,6 +41,9 @@ minetest.is_protected = function(pos, name)
 			  and p.z <= pos.z and (p.z + p.bsizez) >= pos.z) then
 				if( p.owner and p.owner == name ) then
 					return false;
+				-- the player cannot modify other plots, even though he may be house owner of another house and be allowed to modify common ground
+				else
+					return true;
 				end
 			-- if the player just owns another plot in the village, check if it's one where villagers may live
 			elseif( p.owner and p.owner == name ) then