This is no longer necessary.

We have this implemented in Horde_Prefs, and it's incompatible anyway.

framework/Core/lib/Horde/Core/Prefs/Identity.php

@@ -190,24 +190,6 @@ public function getName($ident = null)
         return parent::getName($ident);
     }
 
-    /**
-     * Returns the from address based on the chosen identity. If no
-     * address can be found it is built from the current user name and
-     * the specified maildomain.
-     *
-     * @param integer $ident  The identity to retrieve the address from.
-     *
-     * @return string  A valid from address.
-     */
-    public function getFromAddress($ident = null)
-    {
-        $from = $this->getValue('from_addr', $ident);
-        if (strlen($from)) {
-            return $from;
-        }
-        return $this->_user;
-    }
-
     /**
      * Returns the identity's id that matches the passed addresses.
      *

kronolith/lib/Kronolith.php

@@ -1974,7 +1974,7 @@ public static function sendITipNotifications(
                 $attendee = new Horde_Itip_Resource_Identity(
                         $ident,
                         $vEvent->getAttribute('ATTENDEE'),
-                        $ident->getFromAddress()
+                        (string)$ident->getFromAddress()
                 );
                 /* Find which of the creator's mail addresses is used here */
                 foreach ($event->attendees as $attendeeEmail => $status) {