[imp] Error when searching other user's mailbox

[Jens Grüntjes]

Hello all,

I'm using the current stable Horde Webmail Edition, especially  
imp-6.0.4, webmail-5.0.4.

I experience problem when a certain user searches in another user's  
folder. This is my situation:
User foo has a folder called 'banken' with certain subfolders. The  
folder 'banken' does not contain any messages but the subfolders do.  
User bar is permitted to "lookup" the folder 'banken' and to "lookup"  
and "read" (to say it in "IMAP-ACL") some of the subfolders in  
'banken'. He has no access to the rest of the subfolders.

User bar now performs a search where he searches user foo's folder  
'banken' and all subfolders. The search gets interrupted and a red  
message box appears saying "Fehler während der Kommunikation mit dem  
Server" (sorry it is in German). No search results are displayed. In  
the error log I find the following:

2013-02-25T21:47:17+01:00 ERR: HORDE [imp] Ordner "user.foo.banken"  
konnte nicht geöffnet werden. [pid 6408 on line 387 of  
"/var/www/horde/imp/lib/Imap.php"]
2013-02-25T21:47:17+01:00 DEBUG: HORDE  1.  
Horde_Core_Ajax_Application->doAction()  
/var/www/horde/services/ajax.php:56
  2. call_user_func() /usr/share/php/Horde/Core/Ajax/Application.php:155
  3. IMP_Ajax_Application_Handler_Common->viewPort()
  4. IMP_Ajax_Application->viewPortData()  
/var/www/horde/imp/lib/Ajax/Application/Handler/Common.php:99
  5. IMP_Ajax_Application_ListMessages->listMessages()  
/var/www/horde/imp/lib/Ajax/Application.php:241
  6. count() /var/www/horde/imp/lib/Ajax/Application/ListMessages.php:135
  7. IMP_Mailbox_List->count()
  8. IMP_Mailbox_List->_buildMailbox()  
/var/www/horde/imp/lib/Mailbox/List.php:714
  9. IMP_Imap->search() /var/www/horde/imp/lib/Mailbox/List.php:319
10. IMP_Imap->__call() /var/www/horde/imp/lib/Mailbox/List.php:319
11. Horde_Core_Ajax_Application->doAction()  
/var/www/horde/services/ajax.php:56
12. call_user_func() /usr/share/php/Horde/Core/Ajax/Application.php:155
13. IMP_Ajax_Application_Handler_Common->viewPort()
14. IMP_Ajax_Application->viewPortData()  
/var/www/horde/imp/lib/Ajax/Application/Handler/Common.php:99
15. IMP_Ajax_Application_ListMessages->listMessages()  
/var/www/horde/imp/lib/Ajax/Application.php:241
16. count() /var/www/horde/imp/lib/Ajax/Application/ListMessages.php:135
17. IMP_Mailbox_List->count()
18. IMP_Mailbox_List->_buildMailbox()  
/var/www/horde/imp/lib/Mailbox/List.php:714
19. IMP_Imap->search() /var/www/horde/imp/lib/Mailbox/List.php:319
20. IMP_Imap->__call() /var/www/horde/imp/lib/Mailbox/List.php:319
21. call_user_func_array() /var/www/horde/imp/lib/Imap.php:385
22. Horde_Imap_Client_Base->search()
23. Horde_Imap_Client_Base->openMailbox()  
/usr/share/php/Horde/Imap/Client/Base.php:2195
24. Horde_Imap_Client_Socket->_openMailbox()  
/usr/share/php/Horde/Imap/Client/Base.php:938

2013-02-25T21:47:17+01:00 DEBUG: HORDE [imp] Ordner "user.foo.banken"  
konnte nicht geöffnet werden. [pid 6408 on line 27 of  
"/usr/share/php/Horde/Core/Notification/Handler/Decorator/Hordelog.php"]

Is there a bug in my ACLs or is a bug in the search function? In the  
latter wouldn't it be better to perform the search and skip the  
folders the user is not authorized to search?

Thanks for any hints.
-- 
Viele Grüße
Jens