diff -up yum-3.2.29/yum/config.py.old yum-3.2.29/yum/config.py

--- yum-3.2.29/yum/config.py.old	2015-12-22 16:33:42.907483221 +0100

+++ yum-3.2.29/yum/config.py	2015-12-22 16:34:15.329584138 +0100

@@ -202,7 +202,7 @@ class UrlOption(Option):

         # Handle the "_none_" special case

         if url.lower() == '_none_':

             if self.allow_none:

-                return None

+                return '_none_'

             else:

                 raise ValueError('"_none_" is not a valid value')

diff -up yum-3.2.29/yum/yumRepo.py.old yum-3.2.29/yum/yumRepo.py

--- yum-3.2.29/yum/yumRepo.py.old	2015-12-22 16:35:08.330749108 +0100

+++ yum-3.2.29/yum/yumRepo.py	2015-12-22 16:36:37.668027178 +0100

@@ -432,7 +432,7 @@ class YumRepository(Repository, config.R

         self._proxy_dict = {} # zap it

         proxy_string = None

         empty = (None, '_none_', '')

-        if self.proxy is None:  # got 'proxy=_none_'

+        if self.proxy in empty:  # got 'proxy=_none_'

             proxy_string = ''   # this disables default proxies

         elif self.proxy:

             proxy_string = '%s' % self.proxy