[horde] Spamassassin reporting does not work in Horde/IMP: Call to a member function getFlags() on a non-object

[Bjoern Voigt]

My report https://bugs.horde.org/ticket/14107 is according to Jan
Schneider not a bug, but an configuration problem.

I'd like to provide Spam management functions with buttons like
"Report as Spam".

Unfortunately I get an exception.

The test system has a working Spamassassin configuration. Users
should be able to report additional messages as Spam. My
configuration horde/imp/backends.local.php (based on an example in
horde/imp/backends.php):
> $servers['imap']['spam']['innocent'] = array(
>               'display' => true,
>
>               // Email reporting driver
>               'email' => null,
>               'email_format' => 'digest',
>
>               // Null reporting driver
>               'null' => true,
>
>               // Program reporting driver
>               'program' => null
>           );
> $servers['imap']['spam']['spam'] = array(
>               'display' => true,
>
>               // Email reporting driver
>               'email' => null,
>               'email_format' => 'digest',
>
>               // Null reporting driver
>               'null' => true,
>
>               // Program reporting driver
>               'program' => '/usr/bin/spamc -u mailfilter'
>           );

If I click on the button "Report as Spam" in message view of Basic
view (dynamic view doesn't have these buttons) I get this error message:
> A fatal error has occurred
> Call to a member function getFlags() on a non-object
>
> 1. Horde_ErrorHandler::catchFatalError()
>
> Details
> The full error message is logged in Horde's log file, and is shown 
> below only to administrators. Non-administrative users will not see 
> error details.
>
> ErrorException Object
> (
>      [message:protected] => Call to a member function getFlags()
> on a 
> non-object
>      [string:Exception:private] =>
>      [code:protected] => 0
>      [file:protected] => 
> /srv/www/vhosts/example.com/html/intern/horde/imp/lib/Basic/Message.php
> <http://example.com/html/intern/horde/imp/lib/Basic/Message.php>
>      [line:protected] => 230
>      [trace:Exception:private] => Array
>          (
>              [0] => Array
>                  (
>                      [function] => catchFatalError
>                      [class] => Horde_ErrorHandler
>                      [type] => ::
>                      [args] => Array
>                          (
>                          )
>
>                  )
>
>          )
>
>      [previous:Exception:private] =>
>      [severity:protected] => 1
>      [logged] => 1
> )

The Horde log file doesn't contain entries about this error. The
Apache error log contains:
> [Fri Sep 11 21:30:25.362005 2015] [:error] [pid 12538] [client 
> XXX.XXX.XXX.XXX:41162] PHP Fatal error:  Call to a member function 
> getFlags() on a non-object in 
> /srv/www/vhosts/example.com/html/intern/horde/imp/lib/Basic/Message.php
> <http://example.com/html/intern/horde/imp/lib/Basic/Message.php> on 
> line 230, referer: 
> https://www.example.com/intern/horde/imp/basic.php?mailbox=SU5CT1guc3BhbS5oaWdo&buid=170013&page=message

What is wrong here?

Greetings,
Björn