Wrong ticket # in commit message:
http://git.horde.org/horde-git/-/commit/b76ae2fc4b8a7385da0e5a1b0790585bd689ae98

Not quite up-to-date.

Fatal error: Call to a member function getFlags() on a non-object in 
/home/jan/horde-git/imp/lib/Message.php on line 550
Call Stack
#        Time        Memory        Function        Location
1        0,0001        652808        {main}( )        ../ajax.php:0
2        0,4272        13283280        IMP_Ajax_Application->doAction( )        ../ajax.php:60
3        0,4272        13283280        Horde_Core_Ajax_Application->doAction( 
)        ../Application.php:88
4        0,4272        13283912        call_user_func ( array (0 => class 
IMP_Ajax_Application { public $notify = TRUE; protected $_mbox = class 
IMP_Mailbox { public $cache = array (...); public $changed = 0; 
protected $_import = NULL; protected $_mbox = 'INBOX.Mailinglisten' }; 
protected $_queue = class IMP_Ajax_Queue { protected $_flag = array 
(...); protected $_poll = array (...); protected $_quota = FALSE }; 
protected $_readOnly = array (0 => 'html2Text', 1 => 'text2Html'); 
protected $_app = 'imp'; protected $_action = 'stripAttachment'; 
protected $_vars = class Horde_Variables { protected $_vars = array 
(...); protected $_expectedVariables = array (...); protected 
$_sanitized = FALSE }; protected $_defaultDomain = NULL }, 1 => 
'stripAttachment') )        ../Application.php:95
5        0,4272        13283912        IMP_Ajax_Application->stripAttachment( 
)        ../Application.php:95
6        0,4843        14631000        IMP_Message->stripPart( class IMP_Indices_Form { 
protected $_default = 'SU5CT1g'; protected $_indices = array 
('INBOX.Mailinglisten' => array (0 => '22590')) }, '2', ??? 
)        ../Application.php:1421