[commits] [Wiki] created: ActiveSync/BrokenClientBehavior

[Michael Rubinsky]

mrubinsk  Thu, 29 May 2014 16:53:57 +0000

Created page: http://wiki.horde.org/ActiveSync/BrokenClientBehavior

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+ Known broken !ActiveSync client behavior

Many clients do not follow the published ActiveSync protocol  
specification. In fact, even some of Microsoft's products are guilty  
of this. This page attempts to document some of these idiosyncrasies.  
Horde_ActiveSync attempts to work around those issues that are  
possible to do so. Some broken behavior seems to be wide spread, and  
are documented in the //General// section. More specific behavior is  
documented in client specific sections.


++ General

+++ The sending of STATUS_FOLDERSYNC_REQUIRED (12) is ignored by a  
large number of clients.

This status code is issued in response to a SYNC request when the  
server is unable to locate the folder data in the hierarchy cache.  
I.e., the folder looks to no longer exist. This can happen when  
something causes the server stored state to disappear (like when  
explicitly removing a device from the server) or when something  
corrupts the stored data. This is supposed to trigger the client to  
issue a FOLDERSYNC request to freshen the hierarchy cache. Some  
clients will continue to issue the exact same SYNC request in response  
to this status code, causing a sync loop. Other clients will  
accurately issue the FOLDERSYNC request, but fail to update their  
local cache. Outlook 2013 does this. On receiving new FOLDERSYNC  
responses, it continues to issue SYNC requests on the old folderids  
(though it DOES reset the synckey, so **something** is happening in  
the client, just not the correct something).