net.dns: Avoid duplicate cache entries

[prosody.git] / util / set.lua

diff --git a/util/set.lua b/util/set.lua
index 5f7a9ae243cef7d92bc13c63e1d32aed62bb3cb0..fa065a9c5b8a2f7df7375273df27f1ae06bd8318 100644 (file)
--- a/util/set.lua
+++ b/util/set.lua
@@ -1,12 +1,12 @@
 -- Prosody IM
--- Copyright (C) 2008-2009 Matthew Wild
--- Copyright (C) 2008-2009 Waqas Hussain
+-- Copyright (C) 2008-2010 Matthew Wild
+-- Copyright (C) 2008-2010 Waqas Hussain
 -- 
 -- This project is MIT/X11 licensed. Please see the
 -- COPYING file in the source package for more information.
 --
 
-local ipairs, pairs, setmetatable, next, tostring = 
+local ipairs, pairs, setmetatable, next, tostring =
       ipairs, pairs, setmetatable, next, tostring;
 local t_concat = table.concat;
 
@@ -23,11 +23,12 @@ function set_mt.__sub(set1, set2)
        return _M.difference(set1, set2);
 end
 function set_mt.__div(set, func)
-       local new_set, new_items = _M.new();
+       local new_set = _M.new();
        local items, new_items = set._items, new_set._items;
        for item in pairs(items) do
-               if func(item) then
-                       new_items[item] = true;
+               local new_item = func(item);
+               if new_item ~= nil then
+                       new_items[new_item] = true;
                end
        end
        return new_set;
@@ -82,19 +83,21 @@ function new(list)
        end
        
        function set:add_list(list)
-               for _, item in ipairs(list) do
-                       items[item] = true;
+               if list then
+                       for _, item in ipairs(list) do
+                               items[item] = true;
+                       end
                end
        end
        
        function set:include(otherset)
-               for item in pairs(otherset) do
+               for item in otherset do
                        items[item] = true;
                end
        end
 
        function set:exclude(otherset)
-               for item in pairs(otherset) do
+               for item in otherset do
                        items[item] = nil;
                end
        end