I agree, it looms more clean and double parsnig is awful. Sorry, PHP 
is not my primary profession and the horde internals are overwhelming.

Thanks for fixing it!

I've added the values to the array passed to the 
_buildResponseString() method, but did not do it in the 
Horde_Core_ActiveSync_Driver class.  We should not be doing any input 
stream parsing/manipulation outside of the ActiveSync request 
handlers. Plus, we already have the data parsed, no need to parse it 
again.

Changes have been made in Git (master):

commit 283c402499ed9c6d24df70c6913ab56fccb70b7d
Author: Michael J Rubinsky <mrubinsk@horde.org>
Date:   Mon Nov 5 10:20:00 2012 -0500

     Pass the request_schema and response_schema to the autodiscover response.

     Request: 11637

  .../lib/Horde/ActiveSync/Request/Autodiscover.php  |    6 +++++-
  1 files changed, 5 insertions(+), 1 deletions(-)

http://git.horde.org/horde-git/-/commit/283c402499ed9c6d24df70c6913ab56fccb70b7d

To allow better reaction to different clients performing the 
autodiscover, it is neccessary to store the request-schema and 
response schema in the properties array.

It will be used in a second ActiveSycnc Enhancement I will post as 
tickets in some minutes.

Therefore please extend "/Horde/Core/ActiveSync/Driver.php :: autoDiscover()"
with the following lines:
         xml_parse_into_struct(xml_parser_create(), 
Horde_Rpc::getInput(), $values);
         $results['request_schema'] = $values[0]['attributes']['XMLNS'];
         $results['response_schema'] = $values[3]['value'];

The full function should look like this:
     /**
      * Attempt to autodiscover. Autodiscovery happens before the user is
      * authenticated, and ALWAYS uses the user's email address. We have to
      * do our best to translate email address to username. If this fails, the
      * device simply falls back to requiring full user configuration.
      *
      * @return array
      */
     public function autoDiscover()
     {
         $results = array();

         // Attempt to get a username from the email address.
         $ident = $GLOBALS['injector']
             ->getInstance('Horde_Core_Factory_Identity')
             ->create($GLOBALS['registry']->getAuth());
         $results['display_name'] = $ident->getValue('fullname');
         $results['email'] = $ident->getValue('from_addr');
         $url = parse_url((string)Horde::url(null, true));
         $results['url'] = $url['scheme'] . '://' . $url['host'] . 
'/Microsoft-Server-ActiveSync';
         xml_parse_into_struct(xml_parser_create(), 
Horde_Rpc::getInput(), $values);
         $results['request_schema'] = $values[0]['attributes']['XMLNS'];
         $results['response_schema'] = $values[3]['value'];

         // As of Exchange 2007, this always returns en:en
         $results['culture'] = 'en:en';
         return $results;
     }