diff --git a/plugins/libcalendaring/lib/libcalendaring_itip.php b/plugins/libcalendaring/lib/libcalendaring_itip.php
index 2fd4c257..2e8eba97 100644
--- a/plugins/libcalendaring/lib/libcalendaring_itip.php
+++ b/plugins/libcalendaring/lib/libcalendaring_itip.php
@@ -1,855 +1,920 @@
 <?php
 
 /**
  * iTIP functions for the calendar-based Roudncube plugins
  *
  * Class providing functionality to manage iTIP invitations
  *
  * @author Thomas Bruederli <bruederli@kolabsys.com>
  *
  * Copyright (C) 2011-2014, Kolab Systems AG <contact@kolabsys.com>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
  * published by the Free Software Foundation, either version 3 of the
  * License, or (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  * GNU Affero General Public License for more details.
  *
  * You should have received a copy of the GNU Affero General Public License
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  */
 class libcalendaring_itip
 {
     protected $rc;
     protected $lib;
     protected $plugin;
     protected $sender;
     protected $domain;
     protected $itip_send = false;
     protected $rsvp_actions = array('accepted','tentative','declined','delegated');
     protected $rsvp_status  = array('accepted','tentative','declined','delegated');
 
     function __construct($plugin, $domain = 'libcalendaring')
     {
         $this->plugin = $plugin;
         $this->rc = rcube::get_instance();
         $this->lib = libcalendaring::get_instance();
         $this->domain = $domain;
 
         $hook = $this->rc->plugins->exec_hook('calendar_load_itip',
             array('identity' => $this->rc->user->list_emails(true)));
         $this->sender = $hook['identity'];
 
         $this->plugin->add_hook('smtp_connect', array($this, 'smtp_connect_hook'));
     }
 
     public function set_sender_email($email)
     {
         if (!empty($email))
             $this->sender['email'] = $email;
     }
 
     public function set_rsvp_actions($actions)
     {
         $this->rsvp_actions = (array)$actions;
         $this->rsvp_status = array_merge($this->rsvp_actions, array('delegated'));
     }
 
     public function set_rsvp_status($status)
     {
         $this->rsvp_status = $status;
     }
 
     /**
      * Wrapper for rcube_plugin::gettext()
      * Checking for a label in different domains
      *
      * @see rcube::gettext()
      */
     public function gettext($p)
     {
         $label = is_array($p) ? $p['name'] : $p;
         $domain = $this->domain;
         if (!$this->rc->text_exists($label, $domain)) {
             $domain = 'libcalendaring';
         }
         return $this->rc->gettext($p, $domain);
     }
 
     /**
      * Send an iTip mail message
      *
      * @param array   Event object to send
      * @param string  iTip method (REQUEST|REPLY|CANCEL)
      * @param array   Hash array with recipient data (name, email)
      * @param string  Mail subject
      * @param string  Mail body text label
      * @param object  Mail_mime object with message data
      * @param boolean Request RSVP
      * @return boolean True on success, false on failure
      */
     public function send_itip_message($event, $method, $recipient, $subject, $bodytext, $message = null, $rsvp = true)
     {
         if (!$this->sender['name'])
             $this->sender['name'] = $this->sender['email'];
 
         if (!$message) {
             libcalendaring::identify_recurrence_instance($event);
             $message = $this->compose_itip_message($event, $method, $rsvp);
         }
 
         $mailto = rcube_utils::idn_to_ascii($recipient['email']);
 
         $headers = $message->headers();
         $headers['To'] = format_email_recipient($mailto, $recipient['name']);
         $headers['Subject'] = $this->gettext(array(
             'name' => $subject,
             'vars' => array(
                 'title' => $event['title'],
                 'name' => $this->sender['name']
             )
         ));
 
         // compose a list of all event attendees
         $attendees_list = array();
         foreach ((array)$event['attendees'] as $attendee) {
             $attendees_list[] = ($attendee['name'] && $attendee['email']) ?
                 $attendee['name'] . ' <' . $attendee['email'] . '>' :
                 ($attendee['name'] ? $attendee['name'] : $attendee['email']);
         }
 
         $recurrence_info = '';
         if (!empty($event['recurrence_id'])) {
             $recurrence_info = "\n\n** " . $this->gettext($event['thisandfuture'] ? 'itipmessagefutureoccurrence' : 'itipmessagesingleoccurrence') . ' **';
         }
         else if (!empty($event['recurrence'])) {
             $recurrence_info = sprintf("\n%s: %s", $this->gettext('recurring'), $this->lib->recurrence_text($event['recurrence']));
         }
 
         $mailbody = $this->gettext(array(
             'name' => $bodytext,
             'vars' => array(
                 'title' => $event['title'],
                 'date' => $this->lib->event_date_text($event, true) . $recurrence_info,
                 'attendees' => join(",\n ", $attendees_list),
                 'sender' => $this->sender['name'],
                 'organizer' => $this->sender['name'],
             )
         ));
 
         // if (!empty($event['comment'])) {
         //     $mailbody .= "\n\n" . $this->gettext('itipsendercomment') . $event['comment'];
         // }
 
         // append links for direct invitation replies
         if ($method == 'REQUEST' && $rsvp
             && $this->rc->config->get('calendar_itip_smtp_server')
             && ($token = $this->store_invitation($event, $recipient['email']))
         ) {
             $mailbody .= "\n\n" . $this->gettext(array(
                 'name' => 'invitationattendlinks',
                 'vars' => array('url' => $this->plugin->get_url(array('action' => 'attend', 't' => $token))),
             ));
         }
         else if ($method == 'CANCEL' && $event['cancelled']) {
             $this->cancel_itip_invitation($event);
         }
 
         $message->headers($headers, true);
         $message->setTXTBody(rcube_mime::format_flowed($mailbody, 79));
 
         if ($this->rc->config->get('libcalendaring_itip_debug', false)) {
             rcmail::console('iTip ' . $method, $message->txtHeaders() . "\n\r" . $message->get());
         }
 
         // finally send the message
         $this->itip_send = true;
         $sent = $this->rc->deliver_message($message, $headers['X-Sender'], $mailto, $smtp_error);
         $this->itip_send = false;
 
         return $sent;
     }
 
     /**
      * Plugin hook to alter SMTP authentication.
      * This is used if iTip messages are to be sent from an unauthenticated session
      */
     public function smtp_connect_hook($p)
     {
         // replace smtp auth settings if we're not in an authenticated session
         if ($this->itip_send && !$this->rc->user->ID) {
             foreach (array('smtp_server', 'smtp_user', 'smtp_pass') as $prop) {
                 $p[$prop] = $this->rc->config->get("calendar_itip_$prop", $p[$prop]);
             }
         }
 
       return $p;
     }
 
     /**
      * Helper function to build a Mail_mime object to send an iTip message
      *
      * @param array   Event object to send
      * @param string  iTip method (REQUEST|REPLY|CANCEL)
      * @param boolean Request RSVP
      * @return object Mail_mime object with message data
      */
     public function compose_itip_message($event, $method, $rsvp = true)
     {
         $from     = rcube_utils::idn_to_ascii($this->sender['email']);
         $from_utf = rcube_utils::idn_to_utf8($from);
         $sender   = format_email_recipient($from, $this->sender['name']);
 
         // truncate list attendees down to the recipient of the iTip Reply.
         // constraints for a METHOD:REPLY according to RFC 5546
         if ($method == 'REPLY') {
             $replying_attendee = null;
             $reply_attendees = array();
             foreach ($event['attendees'] as $attendee) {
                 if ($attendee['role'] == 'ORGANIZER') {
                     $reply_attendees[] = $attendee;
                 }
                 else if (strcasecmp($attendee['email'], $from) == 0 || strcasecmp($attendee['email'], $from_utf) == 0) {
                     $replying_attendee = $attendee;
                     if ($attendee['status'] != 'DELEGATED') {
                         unset($replying_attendee['rsvp']);  // unset the RSVP attribute
                     }
                 }
                 // include attendees relevant for delegation (RFC 5546, Section 4.2.5)
                 else if ((!empty($attendee['delegated-to']) &&
                             (strcasecmp($attendee['delegated-to'], $from) == 0 || strcasecmp($attendee['delegated-to'], $from_utf) == 0)) ||
                          (!empty($attendee['delegated-from']) &&
                             (strcasecmp($attendee['delegated-from'], $from) == 0 || strcasecmp($attendee['delegated-from'], $from_utf) == 0))) {
                     $reply_attendees[] = $attendee;
                 }
             }
             if ($replying_attendee) {
                 array_unshift($reply_attendees, $replying_attendee);
                 $event['attendees'] = $reply_attendees;
             }
             if ($event['recurrence']) {
                 unset($event['recurrence']['EXCEPTIONS']);
             }
         }
         // set RSVP for every attendee
         else if ($method == 'REQUEST') {
             foreach ($event['attendees'] as $i => $attendee) {
                 if (($rsvp || !isset($attendee['rsvp'])) && ($attendee['status'] != 'DELEGATED' && $attendee['role'] != 'NON-PARTICIPANT')) {
                     $event['attendees'][$i]['rsvp']= (bool)$rsvp;
                 }
             }
         }
         else if ($method == 'CANCEL') {
             if ($event['recurrence']) {
                 unset($event['recurrence']['EXCEPTIONS']);
             }
         }
 
         // Set SENT-BY property if the sender is not the organizer
         if ($method == 'CANCEL' || $method == 'REQUEST') {
             foreach ((array)$event['attendees'] as $idx => $attendee) {
                 if ($attendee['role'] == 'ORGANIZER'
                     && $attendee['email']
                     && strcasecmp($attendee['email'], $from) != 0
                     && strcasecmp($attendee['email'], $from_utf) != 0
                 ) {
                     $attendee['sent-by'] = 'mailto:' . $from_utf;
                     $event['organizer'] = $event['attendees'][$idx] = $attendee;
                     break;
                 }
             }
         }
 
         // compose multipart message using PEAR:Mail_Mime
         $message = new Mail_mime("\r\n");
         $message->setParam('text_encoding', 'quoted-printable');
         $message->setParam('head_encoding', 'quoted-printable');
         $message->setParam('head_charset', RCUBE_CHARSET);
         $message->setParam('text_charset', RCUBE_CHARSET . ";\r\n format=flowed");
         $message->setContentType('multipart/alternative');
 
         // compose common headers array
         $headers = array(
             'From' => $sender,
             'Date' => $this->rc->user_date(),
             'Message-ID' => $this->rc->gen_message_id(),
             'X-Sender' => $from,
         );
         if ($agent = $this->rc->config->get('useragent')) {
             $headers['User-Agent'] = $agent;
         }
 
         $message->headers($headers);
 
         // attach ics file for this event
         $ical = libcalendaring::get_ical();
         $ics = $ical->export(array($event), $method, false, $method == 'REQUEST' && $this->plugin->driver ? array($this->plugin->driver, 'get_attachment_body') : false);
         $filename = $event['_type'] == 'task' ? 'todo.ics' : 'event.ics';
         $message->addAttachment($ics, 'text/calendar', $filename, false, '8bit', '', RCUBE_CHARSET . "; method=" . $method);
 
         return $message;
     }
 
     /**
      * Forward the given iTip event as delegation to another person
      *
      * @param array Event object to delegate
      * @param mixed Delegatee as string or hash array with keys 'name' and 'mailto'
      * @param boolean The delegator's RSVP flag
      * @param array List with indexes of new/updated attendees
      * @return boolean True on success, False on failure
      */
     public function delegate_to(&$event, $delegate, $rsvp = false, &$attendees = array())
     {
         if (is_string($delegate)) {
             $delegates = rcube_mime::decode_address_list($delegate, 1, false);
             if (count($delegates) > 0) {
                 $delegate = reset($delegates);
             }
         }
 
         $emails = $this->lib->get_user_emails();
         $me     = $this->rc->user->list_emails(true);
 
         // find/create the delegate attendee
         $delegate_attendee = array(
             'email' => $delegate['mailto'],
             'name'  => $delegate['name'],
             'role'  => 'REQ-PARTICIPANT',
         );
         $delegate_index = count($event['attendees']);
 
         foreach ($event['attendees'] as $i => $attendee) {
           // set myself the DELEGATED-TO parameter
           if ($attendee['email'] && in_array(strtolower($attendee['email']), $emails)) {
               $event['attendees'][$i]['delegated-to'] = $delegate['mailto'];
               $event['attendees'][$i]['status'] = 'DELEGATED';
               $event['attendees'][$i]['role'] = 'NON-PARTICIPANT';
               $event['attendees'][$i]['rsvp'] = $rsvp;
 
               $me['email'] = $attendee['email'];
               $delegate_attendee['role'] = $attendee['role'];
           }
           // the disired delegatee is already listed as an attendee
           else if (stripos($delegate['mailto'], $attendee['email']) !== false && $attendee['role'] != 'ORGANIZER') {
               $delegate_attendee = $attendee;
               $delegate_index = $i;
               break;
           }
           // TODO: remove previous delegatee (i.e. attendee that has DELEGATED-FROM == $me)
         }
 
         // set/add delegate attendee with RSVP=TRUE and DELEGATED-FROM parameter
         $delegate_attendee['rsvp'] = true;
         $delegate_attendee['status'] = 'NEEDS-ACTION';
         $delegate_attendee['delegated-from'] = $me['email'];
         $event['attendees'][$delegate_index] = $delegate_attendee;
 
         $attendees[] = $delegate_index;
 
         $this->set_sender_email($me['email']);
         return $this->send_itip_message($event, 'REQUEST', $delegate_attendee, 'itipsubjectdelegatedto', 'itipmailbodydelegatedto');
     }
 
     /**
      * Handler for calendar/itip-status requests
      */
     public function get_itip_status($event, $existing = null)
     {
       $action = $event['rsvp'] ? 'rsvp' : '';
       $status = $event['fallback'];
-      $latest = $resheduled = false;
+      $latest = $rescheduled = false;
       $html   = '';
 
       if (is_numeric($event['changed']))
         $event['changed'] = new DateTime('@'.$event['changed']);
 
       // check if the given itip object matches the last state
       if ($existing) {
         $latest = (isset($event['sequence']) && intval($existing['sequence']) == intval($event['sequence'])) ||
                   (!isset($event['sequence']) && $existing['changed'] && $existing['changed'] >= $event['changed']);
       }
 
       // determine action for REQUEST
       if ($event['method'] == 'REQUEST') {
         $html = html::div('rsvp-status', $this->gettext('acceptinvitation'));
 
         if ($existing) {
           $rsvp = $event['rsvp'];
           $emails = $this->lib->get_user_emails();
           foreach ($existing['attendees'] as $attendee) {
             if ($attendee['email'] && in_array(strtolower($attendee['email']), $emails)) {
               $status = strtoupper($attendee['status']);
               break;
             }
           }
 
           // Detect re-sheduling
           if (!$latest) {
             // FIXME: This is probably to simplistic, or maybe we should just check
             //        attendee's RSVP flag in the new event?
-            $resheduled = $existing['start'] != $event['start'] || $existing['end'] > $event['end'];
+            $rescheduled = $existing['start'] != $event['start'] || $existing['end'] > $event['end'];
           }
         }
         else {
           $rsvp = $event['rsvp'] && $this->rc->config->get('calendar_allow_itip_uninvited', true);
         }
 
         $status_lc = strtolower($status);
 
         if ($status_lc == 'unknown' && !$this->rc->config->get('calendar_allow_itip_uninvited', true)) {
           $html = html::div('rsvp-status', $this->gettext('notanattendee'));
           $action = 'import';
         }
         else if (in_array($status_lc, $this->rsvp_status)) {
           $status_text = $this->gettext(($latest ? 'youhave' : 'youhavepreviously') . $status_lc);
 
           if ($existing && ($existing['sequence'] > $event['sequence'] || (!isset($event['sequence']) && $existing['changed'] && $existing['changed'] > $event['changed']))) {
             $action = '';  // nothing to do here, outdated invitation
             if ($status_lc == 'needs-action')
               $status_text = $this->gettext('outdatedinvitation');
           }
           else if (!$existing && !$rsvp) {
             $action = 'import';
           }
-          else if ($resheduled) {
+          else if ($rescheduled) {
             $action = 'rsvp';
           }
           else if ($status_lc != 'needs-action') {
+            // check if there are any changes
+            if ($latest) {
+              $diff   = $this->get_itip_diff($event, $existing);
+              $latest = empty($diff);
+            }
+
             $action = !$latest ? 'update' : '';
           }
 
           $html = html::div('rsvp-status ' . $status_lc, $status_text);
         }
       }
       // determine action for REPLY
       else if ($event['method'] == 'REPLY') {
         // check whether the sender already is an attendee
         if ($existing) {
           $action = $this->rc->config->get('calendar_allow_itip_uninvited', true) ? 'accept' : '';
           $listed = false;
           foreach ($existing['attendees'] as $attendee) {
             if ($attendee['role'] != 'ORGANIZER' && strcasecmp($attendee['email'], $event['attendee']) == 0) {
               $status_lc = strtolower($status);
               if (in_array($status_lc, $this->rsvp_status)) {
                 $html = html::div('rsvp-status ' . $status_lc, $this->gettext(array(
                     'name' => 'attendee' . $status_lc,
                     'vars' => array(
                         'delegatedto' => rcube::Q($event['delegated-to'] ?: ($attendee['delegated-to'] ?: '?')),
                     )
                 )));
               }
               $action = $attendee['status'] == $status || !$latest ? '' : 'update';
               $listed = true;
               break;
             }
           }
 
           if (!$listed) {
             $html = html::div('rsvp-status', $this->gettext('itipnewattendee'));
           }
         }
         else {
           $html = html::div('rsvp-status hint', $this->gettext('itipobjectnotfound'));
           $action = '';
         }
       }
       else if ($event['method'] == 'CANCEL') {
         if (!$existing) {
           $html = html::div('rsvp-status hint', $this->gettext('itipobjectnotfound'));
           $action = '';
         }
       }
 
       return array(
           'uid'        => $event['uid'],
           'id'         => asciiwords($event['uid'], true),
           'existing'   => $existing ? true : false,
           'saved'      => $existing ? true : false,
           'latest'     => $latest,
           'status'     => $status,
           'action'     => $action,
-          'resheduled' => $resheduled,
+          'rescheduled' => $rescheduled,
           'html'       => $html,
       );
     }
 
+    protected function get_itip_diff($event, $existing)
+    {
+        if (empty($event) || empty($existing) || empty($event['message_uid'])) {
+            return;
+        }
+
+        $itip = $this->lib->mail_get_itip_object($event['mbox'], $event['message_uid'], $event['mime_id'],
+            $event['task'] == 'calendar' ? 'event' : 'task');
+
+        if ($itip) {
+            // List of properties that could change without SEQUENCE bump
+            $attrs = array('description', 'title', 'location', 'url');
+            $diff  = array();
+
+            foreach ($attrs as $attr) {
+                if (isset($itip[$attr]) && $itip[$attr] != $existing[$attr]) {
+                    $diff[$attr] = array(
+                        'new' => $itip[$attr],
+                        'old' => $existing[$attr]
+                    );
+                }
+            }
+
+            $status             = array();
+            $itip_attendees     = array();
+            $existing_attendees = array();
+            $emails             = $this->lib->get_user_emails();
+
+            // Compare list of attendees (ignoring current user status)
+            foreach ((array) $existing['attendees'] as $idx => $attendee) {
+                if ($attendee['email'] && in_array(strtolower($attendee['email']), $emails)) {
+                    $status[strtolower($attendee['email'])] = $attendee['status'];
+                }
+                if ($attendee['role'] == 'ORGANIZER') {
+                    $attendee['status'] = 'ACCEPTED'; // sometimes is not set for exceptions
+                    $existing['attendees'][$idx] = $attendee;
+                }
+                $existing_attendees[] = $attendee['email'].$attendee['name'];
+            }
+            foreach ((array) $itip['attendees'] as $idx => $attendee) {
+                if ($attendee['email'] && ($_status = $status[strtolower($attendee['email'])])) {
+                    $attendee['status'] = $_status;
+                    $itip['attendees'][$idx] = $attendee;
+                }
+                $itip_attendees[] = $attendee['email'].$attendee['name'];
+            }
+
+            if ($itip_attendees != $existing_attendees) {
+                $diff['attendees'] = array(
+                    'new' => $itip['attendees'],
+                    'old' => $existing['attendees']
+                );
+            }
+
+            return $diff;
+        }
+    }
+
     /**
      * Build inline UI elements for iTip messages
      */
     public function mail_itip_inline_ui($event, $method, $mime_id, $task, $message_date = null, $preview_url = null)
     {
         $buttons = array();
         $dom_id = asciiwords($event['uid'], true);
         $rsvp_status = 'unknown';
 
         // pass some metadata about the event and trigger the asynchronous status check
         $changed = is_object($event['changed']) ? $event['changed'] : $message_date;
         $metadata = array(
             'uid'      => $event['uid'],
             '_instance' => $event['_instance'],
             'changed'  => $changed ? $changed->format('U') : 0,
             'sequence' => intval($event['sequence']),
             'method'   => $method,
             'task'     => $task,
+            'mime_id'  => $mime_id,
         );
 
         // create buttons to be activated from async request checking existence of this event in local calendars
         $buttons[] = html::div(array('id' => 'loading-'.$dom_id, 'class' => 'rsvp-status loading'), $this->gettext('loading'));
 
         // on iTip REPLY we have two options:
         if ($method == 'REPLY') {
             $title = $this->gettext('itipreply');
 
             foreach ($event['attendees'] as $attendee) {
                 if (!empty($attendee['email']) && $attendee['role'] != 'ORGANIZER') {
                     if (empty($event['_sender']) || self::compare_email($attendee['email'], $event['_sender'], $event['_sender_utf'])) {
                         $metadata['attendee'] = $attendee['email'];
                         $rsvp_status = strtoupper($attendee['status']);
                         if ($attendee['delegated-to']) {
                             $metadata['delegated-to'] = $attendee['delegated-to'];
                         }
                         break;
                     }
                 }
             }
 
             // 1. update the attendee status on our copy
             $update_button = html::tag('input', array(
                 'type' => 'button',
                 'class' => 'button',
                 'onclick' => "rcube_libcalendaring.add_from_itip_mail('" . rcube::JQ($mime_id) . "', '$task')",
                 'value' => $this->gettext('updateattendeestatus'),
             ));
 
             // 2. accept or decline a new or delegate attendee
             $accept_buttons = html::tag('input', array(
                 'type' => 'button',
                 'class' => "button accept",
                 'onclick' => "rcube_libcalendaring.add_from_itip_mail('" . rcube::JQ($mime_id) . "', '$task')",
                 'value' => $this->gettext('acceptattendee'),
             ));
             $accept_buttons .= html::tag('input', array(
                 'type' => 'button',
                 'class' => "button decline",
                 'onclick' => "rcube_libcalendaring.decline_attendee_reply('" . rcube::JQ($mime_id) . "', '$task')",
                 'value' => $this->gettext('declineattendee'),
             ));
 
             $buttons[] = html::div(array('id' => 'update-'.$dom_id, 'style' => 'display:none'), $update_button);
             $buttons[] = html::div(array('id' => 'accept-'.$dom_id, 'style' => 'display:none'), $accept_buttons);
         }
         // when receiving iTip REQUEST messages:
         else if ($method == 'REQUEST') {
             $emails = $this->lib->get_user_emails();
             $title = $event['sequence'] > 0 ? $this->gettext('itipupdate') : $this->gettext('itipinvitation');
             $metadata['rsvp'] = true;
             $metadata['sensitivity'] = $event['sensitivity'];
 
             if (is_object($event['start'])) {
                 $metadata['date'] = $event['start']->format('U');
             }
 
             // check for X-KOLAB-INVITATIONTYPE property and only show accept/decline buttons
             if (self::get_custom_property($event, 'X-KOLAB-INVITATIONTYPE') == 'CONFIRMATION') {
                 $this->rsvp_actions = array('accepted','declined');
                 $metadata['nosave'] = true;
             }
 
             // 1. display RSVP buttons (if the user was invited)
             foreach ($this->rsvp_actions as $method) {
                 $rsvp_buttons .= html::tag('input', array(
                     'type' => 'button',
                     'class' => "button $method",
                     'onclick' => "rcube_libcalendaring.add_from_itip_mail('" . rcube::JQ($mime_id) . "', '$task', '$method', '$dom_id')",
                     'value' => $this->gettext('itip' . $method),
                 ));
             }
 
             // add button to open calendar/preview
             if (!empty($preview_url)) {
               $msgref = $this->lib->ical_message->folder . '/' . $this->lib->ical_message->uid . '#' . $mime_id;
               $rsvp_buttons .= html::tag('input', array(
                   'type' => 'button',
                   'class' => "button preview",
                   'onclick' => "rcube_libcalendaring.open_itip_preview('" . rcube::JQ($preview_url) . "', '" . rcube::JQ($msgref) . "')",
                   'value' => $this->gettext('openpreview'),
               ));
             }
 
             // 2. update the local copy with minor changes
             $update_button = html::tag('input', array(
                 'type' => 'button',
                 'class' => 'button',
                 'onclick' => "rcube_libcalendaring.add_from_itip_mail('" . rcube::JQ($mime_id) . "', '$task')",
                 'value' => $this->gettext('updatemycopy'),
             ));
 
             // 3. Simply import the event without replying
             $import_button = html::tag('input', array(
                 'type' => 'button',
                 'class' => 'button',
                 'onclick' => "rcube_libcalendaring.add_from_itip_mail('" . rcube::JQ($mime_id) . "', '$task')",
                 'value' => $this->gettext('importtocalendar'),
             ));
 
             // check my status
             foreach ($event['attendees'] as $attendee) {
                 if ($attendee['email'] && in_array(strtolower($attendee['email']), $emails)) {
                     $metadata['attendee'] = $attendee['email'];
                     $metadata['rsvp'] = $attendee['rsvp'] || $attendee['role'] != 'NON-PARTICIPANT';
                     $rsvp_status = !empty($attendee['status']) ? strtoupper($attendee['status']) : 'NEEDS-ACTION';
                     break;
                 }
             }
 
             // add itip reply message controls
             $rsvp_buttons .= html::div('itip-reply-controls', $this->itip_rsvp_options_ui($dom_id, $metadata['nosave']));
 
             $buttons[] = html::div(array('id' => 'rsvp-'.$dom_id, 'class' => 'rsvp-buttons', 'style' => 'display:none'), $rsvp_buttons);
             $buttons[] = html::div(array('id' => 'update-'.$dom_id, 'style' => 'display:none'), $update_button);
 
             // prepare autocompletion for delegation dialog
             if (in_array('delegated', $this->rsvp_actions)) {
                 $this->rc->autocomplete_init();
             }
         }
         // for CANCEL messages, we can:
         else if ($method == 'CANCEL') {
             $title = $this->gettext('itipcancellation');
             $event_prop = array_filter(array(
               'uid' => $event['uid'],
               '_instance' => $event['_instance'],
               '_savemode' => $event['_savemode'],
             ));
 
             // 1. remove the event from our calendar
             $button_remove = html::tag('input', array(
                 'type' => 'button',
                 'class' => 'button',
                 'onclick' => "rcube_libcalendaring.remove_from_itip(" . rcube_output::json_serialize($event_prop) . ", '$task', '" . rcube::JQ($event['title']) . "')",
                 'value' => $this->gettext('removefromcalendar'),
             ));
 
             // 2. update our copy with status=cancelled
             $button_update = html::tag('input', array(
               'type' => 'button',
               'class' => 'button',
               'onclick' => "rcube_libcalendaring.add_from_itip_mail('" . rcube::JQ($mime_id) . "', '$task')",
               'value' => $this->gettext('updatemycopy'),
             ));
 
             $buttons[] = html::div(array('id' => 'rsvp-'.$dom_id, 'style' => 'display:none'), $button_remove . $button_update);
 
             $rsvp_status = 'CANCELLED';
             $metadata['rsvp'] = true;
         }
 
         // append generic import button
         if ($import_button) {
             $buttons[] = html::div(array('id' => 'import-'.$dom_id, 'style' => 'display:none'), $import_button);
         }
 
         // pass some metadata about the event and trigger the asynchronous status check
         $metadata['fallback'] = $rsvp_status;
         $metadata['rsvp'] = intval($metadata['rsvp']);
 
         $this->rc->output->add_script("rcube_libcalendaring.fetch_itip_object_status(" . rcube_output::json_serialize($metadata) . ")", 'docready');
 
         // get localized texts from the right domain
         foreach (array('savingdata','deleteobjectconfirm','declinedeleteconfirm','declineattendee',
             'cancel','itipdelegated','declineattendeeconfirm','itipcomment','delegateinvitation',
             'delegateto','delegatersvpme','delegateinvalidaddress') as $label) {
           $this->rc->output->command('add_label', "itip.$label", $this->gettext($label));
         }
 
         // show event details with buttons
         return $this->itip_object_details_table($event, $title) .
             html::div(array('class' => 'itip-buttons', 'id' => 'itip-buttons-' . asciiwords($metadata['uid'], true)), join('', $buttons));
     }
 
     /**
      * Render an RSVP UI widget with buttons to respond on iTip invitations
      */
     function itip_rsvp_buttons($attrib = array(), $actions = null)
     {
         $attrib += array('type' => 'button');
 
         if (!$actions)
             $actions = $this->rsvp_actions;
 
         foreach ($actions as $method) {
             $buttons .= html::tag('input', array(
                 'type'  => $attrib['type'],
                 'name'  => $attrib['iname'],
                 'class' => 'button',
                 'rel'   => $method,
                 'value' => $this->gettext('itip' . $method),
             ));
         }
 
         // add localized texts for the delegation dialog
         if (in_array('delegated', $actions)) {
             foreach (array('itipdelegated','itipcomment','delegateinvitation',
                   'delegateto','delegatersvpme','delegateinvalidaddress','cancel') as $label) {
                 $this->rc->output->command('add_label', "itip.$label", $this->gettext($label));
             }
         }
 
         foreach (array('all','current','future') as $mode) {
             $this->rc->output->command('add_label', "rsvpmode$mode", $this->gettext("rsvpmode$mode"));
         }
 
         $savemode_radio = new html_radiobutton(array('name' => '_rsvpmode', 'class' => 'rsvp-replymode'));
 
         return html::div($attrib,
             html::div('label', $this->gettext('acceptinvitation')) .
             html::div('rsvp-buttons',
                 $buttons .
                 html::div('itip-reply-controls', $this->itip_rsvp_options_ui($attrib['id']))
             )
         );
     }
 
     /**
      * Render UI elements to control iTip reply message sending
      */
     public function itip_rsvp_options_ui($dom_id, $disable = false)
     {
         $itip_sending = $this->rc->config->get('calendar_itip_send_option', 3);
 
         // itip sending is entirely disabled
         if ($itip_sending === 0) {
             return '';
         }
         // add checkbox to suppress itip reply message
         else if ($itip_sending >= 2) {
             $rsvp_additions = html::label(array('class' => 'noreply-toggle'),
                 html::tag('input', array('type' => 'checkbox', 'id' => 'noreply-'.$dom_id, 'value' => 1, 'disabled' => $disable, 'checked' => ($itip_sending & 1) == 0))
                 . ' ' . $this->gettext('itipsuppressreply')
             );
         }
 
         // add input field for reply comment
         $toggle_attrib = array(
             'href'    => '#toggle',
             'class'   => 'reply-comment-toggle',
             'onclick' => '$(this).hide().parent().find(\'textarea\').show().focus()'
         );
         $textarea_attrib = array(
             'id'    => 'reply-comment-' . $dom_id,
             'name'  => '_comment',
             'cols'  => 40,
             'rows'  => 6,
             'style' => 'display:none',
             'placeholder' => $this->gettext('itipcomment')
         );
 
         $rsvp_additions .= html::a($toggle_attrib, $this->gettext('itipeditresponse'))
             . html::div('itip-reply-comment', html::tag('textarea', $textarea_attrib, ''));
 
         return $rsvp_additions;
     }
 
     /**
      * Render event/task details in a table
      */
     function itip_object_details_table($event, $title)
     {
         $table = new html_table(array('cols' => 2, 'border' => 0, 'class' => 'calendar-eventdetails'));
         $table->add('ititle', $title);
         $table->add('title', rcube::Q($event['title']));
         if ($event['start'] && $event['end']) {
             $table->add('label', $this->gettext('date'));
             $table->add('date', rcube::Q($this->lib->event_date_text($event)));
         }
         else if ($event['due'] && $event['_type'] == 'task') {
             $table->add('label', $this->gettext('date'));
             $table->add('date', rcube::Q($this->lib->event_date_text($event)));
         }
         if (!empty($event['recurrence_date'])) {
             $table->add('label', '');
             $table->add('recurrence-id', $this->gettext($event['thisandfuture'] ? 'itipfutureoccurrence' : 'itipsingleoccurrence'));
         }
         else if (!empty($event['recurrence'])) {
             $table->add('label', $this->gettext('recurring'));
             $table->add('recurrence', $this->lib->recurrence_text($event['recurrence']));
         }
         if ($event['location']) {
             $table->add('label', $this->gettext('location'));
             $table->add('location', rcube::Q($event['location']));
         }
         if ($event['sensitivity'] && $event['sensitivity'] != 'public') {
             $table->add('label', $this->gettext('sensitivity'));
             $table->add('sensitivity', ucfirst($this->gettext($event['sensitivity'])) . '!');
         }
         if ($event['status'] == 'COMPLETED' || $event['status'] == 'CANCELLED') {
             $table->add('label', $this->gettext('status'));
             $table->add('status', $this->gettext('status-' . strtolower($event['status'])));
         }
         if ($event['comment']) {
             $table->add('label', $this->gettext('comment'));
             $table->add('location', rcube::Q($event['comment']));
         }
 
         return $table->show();
     }
 
 
     /**
      * Create iTIP invitation token for later replies via URL
      *
      * @param array Hash array with event properties
      * @param string Attendee email address
      * @return string Invitation token
      */
     public function store_invitation($event, $attendee)
     {
         // empty stub
         return false;
     }
 
     /**
      * Mark invitations for the given event as cancelled
      *
      * @param array Hash array with event properties
      */
     public function cancel_itip_invitation($event)
     {
         // empty stub
         return false;
     }
 
     /**
      * Utility function to get the value of a custom property
      */
     public static function get_custom_property($event, $name)
     {
       $ret = false;
 
       if (is_array($event['x-custom'])) {
           array_walk($event['x-custom'], function($prop, $i) use ($name, &$ret) {
               if (strcasecmp($prop[0], $name) === 0) {
                   $ret = $prop[1];
               }
           });
       }
 
       return $ret;
     }
 
     /**
      * Compare email address
      */
     public static function compare_email($value, $email, $email_utf = null)
     {
         $v1 = !empty($email) && strcasecmp($value, $email) === 0;
         $v2 = !empty($email_utf) && strcasecmp($value, $email_utf) === 0;
 
         return $v1 || $v2;
     }
 }
diff --git a/plugins/libcalendaring/libcalendaring.js b/plugins/libcalendaring/libcalendaring.js
index 5c9ae6e9..401471af 100644
--- a/plugins/libcalendaring/libcalendaring.js
+++ b/plugins/libcalendaring/libcalendaring.js
@@ -1,1460 +1,1462 @@
 /**
  * Basic Javascript utilities for calendar-related plugins
  *
  * @author Thomas Bruederli <bruederli@kolabsys.com>
  *
  * @licstart  The following is the entire license notice for the
  * JavaScript code in this page.
  *
  * Copyright (C) 2012-2015, Kolab Systems AG <contact@kolabsys.com>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
  * published by the Free Software Foundation, either version 3 of the
  * License, or (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  * GNU Affero General Public License for more details.
  *
  * You should have received a copy of the GNU Affero General Public License
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  *
  * @licend  The above is the entire license notice
  * for the JavaScript code in this page.
  */
 
 function rcube_libcalendaring(settings)
 {
     // member vars
     this.settings = settings || {};
     this.alarm_ids = [];
     this.alarm_dialog = null;
     this.snooze_popup = null;
     this.dismiss_link = null;
     this.group2expand = {};
 
     // abort if env isn't set
     if (!settings || !settings.date_format)
       return;
 
     // private vars
     var me = this;
     var gmt_offset = (new Date().getTimezoneOffset() / -60) - (settings.timezone || 0) - (settings.dst || 0);
     var client_timezone = new Date().getTimezoneOffset();
 
     // general datepicker settings
     var datepicker_settings = {
         // translate from fullcalendar format to datepicker format
         dateFormat: settings.date_format.replace(/M/g, 'm').replace(/mmmmm/, 'MM').replace(/mmm/, 'M').replace(/dddd/, 'DD').replace(/ddd/, 'D').replace(/yy/g, 'y'),
         firstDay : settings.first_day,
         dayNamesMin: settings.days_short,
         monthNames: settings.months,
         monthNamesShort: settings.months,
         changeMonth: false,
         showOtherMonths: true,
         selectOtherMonths: true
     };
 
 
     /**
      * Quote html entities
      */
     var Q = this.quote_html = function(str)
     {
       return String(str).replace(/</g, '&lt;').replace(/>/g, '&gt;').replace(/"/g, '&quot;');
     };
 
     /**
      * Create a nice human-readable string for the date/time range
      */
     this.event_date_text = function(event, voice)
     {
       if (!event.start)
         return '';
       if (!event.end)
         event.end = event.start;
 
       var fromto, duration = event.end.getTime() / 1000 - event.start.getTime() / 1000,
         until = voice ? ' ' + rcmail.gettext('until','libcalendaring') + ' ' : ' — ';
       if (event.allDay) {
         fromto = this.format_datetime(event.start, 1, voice)
           + (duration > 86400 || event.start.getDay() != event.end.getDay() ? until + this.format_datetime(event.end, 1, voice) : '');
       }
       else if (duration < 86400 && event.start.getDay() == event.end.getDay()) {
         fromto = this.format_datetime(event.start, 0, voice)
           + (duration > 0 ? until + this.format_datetime(event.end, 2, voice) : '');
       }
       else {
         fromto = this.format_datetime(event.start, 0, voice)
           + (duration > 0 ? until + this.format_datetime(event.end, 0, voice) : '');
       }
 
       return fromto;
     };
 
     /**
      * Checks if the event/task has 'real' attendees, excluding the current user
      */
     this.has_attendees = function(event)
     {
         return !!(event.attendees && event.attendees.length && (event.attendees.length > 1 || String(event.attendees[0].email).toLowerCase() != settings.identity.email));
     };
 
     /**
      * Check if the current user is an attendee of this event/task
      */
     this.is_attendee = function(event, role, email)
     {
         var i, emails = email ? ';' + email.toLowerCase() : settings.identity.emails;
 
         for (i=0; event.attendees && i < event.attendees.length; i++) {
             if ((!role || event.attendees[i].role == role) && event.attendees[i].email && emails.indexOf(';'+event.attendees[i].email.toLowerCase()) >= 0) {
                 return event.attendees[i];
             }
         }
 
         return false;
     };
 
     /**
      * Checks if the current user is the organizer of the event/task
      */
     this.is_organizer = function(event, email)
     {
         return this.is_attendee(event, 'ORGANIZER', email) || !event.id;
     };
 
     /**
      * Check permissions on the given folder object
      */
     this.has_permission = function(folder, perm)
     {
         // multiple chars means "either of"
         if (String(perm).length > 1) {
             for (var i=0; i < perm.length; i++) {
                 if (this.has_permission(folder, perm[i])) {
                     return true;
                 }
             }
         }
 
         if (folder.rights && String(folder.rights).indexOf(perm) >= 0) {
             return true;
         }
 
         return (perm == 'i' && folder.editable) || (perm == 'v' && folder.editable);
     };
 
 
     /**
      * From time and date strings to a real date object
      */
     this.parse_datetime = function(time, date)
     {
         // we use the utility function from datepicker to parse dates
         var date = date ? $.datepicker.parseDate(datepicker_settings.dateFormat, date, datepicker_settings) : new Date();
 
         var time_arr = time.replace(/\s*[ap][.m]*/i, '').replace(/0([0-9])/g, '$1').split(/[:.]/);
         if (!isNaN(time_arr[0])) {
             date.setHours(time_arr[0]);
         if (time.match(/p[.m]*/i) && date.getHours() < 12)
             date.setHours(parseInt(time_arr[0]) + 12);
         else if (time.match(/a[.m]*/i) && date.getHours() == 12)
             date.setHours(0);
       }
       if (!isNaN(time_arr[1]))
             date.setMinutes(time_arr[1]);
 
       return date;
     }
 
     /**
      * Convert an ISO 8601 formatted date string from the server into a Date object.
      * Timezone information will be ignored, the server already provides dates in user's timezone.
      */
     this.parseISO8601 = function(s)
     {
         // force d to be on check's YMD, for daylight savings purposes
         var fixDate = function(d, check) {
             if (+d) { // prevent infinite looping on invalid dates
                 while (d.getDate() != check.getDate()) {
                     d.setTime(+d + (d < check ? 1 : -1) * 3600000);
                 }
             }
         }
 
         // derived from http://delete.me.uk/2005/03/iso8601.html
         var m = s && s.match(/^([0-9]{4})(-([0-9]{2})(-([0-9]{2})([T ]([0-9]{2}):([0-9]{2})(:([0-9]{2})(\.([0-9]+))?)?(Z|(([-+])([0-9]{2})(:?([0-9]{2}))?))?)?)?)?$/);
         if (!m) {
             return null;
         }
 
         var date = new Date(m[1], 0, 2),
             check = new Date(m[1], 0, 2, 9, 0);
         if (m[3]) {
             date.setMonth(m[3] - 1);
             check.setMonth(m[3] - 1);
         }
         if (m[5]) {
             date.setDate(m[5]);
             check.setDate(m[5]);
         }
         fixDate(date, check);
         if (m[7]) {
             date.setHours(m[7]);
         }
         if (m[8]) {
             date.setMinutes(m[8]);
         }
         if (m[10]) {
             date.setSeconds(m[10]);
         }
         if (m[12]) {
             date.setMilliseconds(Number("0." + m[12]) * 1000);
         }
         fixDate(date, check);
 
         return date;
     }
 
     /**
      * Turn the given date into an ISO 8601 date string understandable by PHPs strtotime()
      */
     this.date2ISO8601 = function(date)
     {
         var zeropad = function(num) { return (num < 10 ? '0' : '') + num; };
 
         return date.getFullYear() + '-' + zeropad(date.getMonth()+1) + '-' + zeropad(date.getDate())
             + 'T' + zeropad(date.getHours()) + ':' + zeropad(date.getMinutes()) + ':' + zeropad(date.getSeconds());
     };
 
     /**
      * Format the given date object according to user's prefs
      */
     this.format_datetime = function(date, mode, voice)
     {
         var res = '';
         if (!mode || mode == 1) {
           res += $.datepicker.formatDate(voice ? 'MM d yy' : datepicker_settings.dateFormat, date, datepicker_settings);
         }
         if (!mode) {
             res += voice ? ' ' + rcmail.gettext('at','libcalendaring') + ' ' : ' ';
         }
         if (!mode || mode == 2) {
             res += this.format_time(date, voice);
         }
 
         return res;
     }
 
     /**
      * Clone from fullcalendar.js
      */
     this.format_time = function(date, voice)
     {
         var zeroPad = function(n) { return (n < 10 ? '0' : '') + n; }
         var formatters = {
             s   : function(d) { return d.getSeconds() },
             ss  : function(d) { return zeroPad(d.getSeconds()) },
             m   : function(d) { return d.getMinutes() },
             mm  : function(d) { return zeroPad(d.getMinutes()) },
             h   : function(d) { return d.getHours() % 12 || 12 },
             hh  : function(d) { return zeroPad(d.getHours() % 12 || 12) },
             H   : function(d) { return d.getHours() },
             HH  : function(d) { return zeroPad(d.getHours()) },
             t   : function(d) { return d.getHours() < 12 ? 'a' : 'p' },
             tt  : function(d) { return d.getHours() < 12 ? 'am' : 'pm' },
             T   : function(d) { return d.getHours() < 12 ? 'A' : 'P' },
             TT  : function(d) { return d.getHours() < 12 ? 'AM' : 'PM' }
         };
 
         var i, i2, c, formatter, res = '',
           format = voice ? settings['time_format'].replace(':',' ').replace('HH','H').replace('hh','h').replace('mm','m').replace('ss','s') : settings['time_format'];
         for (i=0; i < format.length; i++) {
             c = format.charAt(i);
             for (i2=Math.min(i+2, format.length); i2 > i; i2--) {
                 if (formatter = formatters[format.substring(i, i2)]) {
                     res += formatter(date);
                     i = i2 - 1;
                     break;
                 }
             }
             if (i2 == i) {
                 res += c;
             }
         }
 
         return res;
     }
 
     /**
      * Convert the given Date object into a unix timestamp respecting browser's and user's timezone settings
      */
     this.date2unixtime = function(date)
     {
         var dst_offset = (client_timezone - date.getTimezoneOffset()) * 60;  // adjust DST offset
         return Math.round(date.getTime()/1000 + gmt_offset * 3600 + dst_offset);
     }
 
     /**
      * Turn a unix timestamp value into a Date object
      */
     this.fromunixtime = function(ts)
     {
         ts -= gmt_offset * 3600;
         var date = new Date(ts * 1000),
             dst_offset = (client_timezone - date.getTimezoneOffset()) * 60;
         if (dst_offset)  // adjust DST offset
             date.setTime((ts + 3600) * 1000);
         return date;
     }
 
     /**
      * Simple plaintext to HTML converter, makig URLs clickable
      */
     this.text2html = function(str, maxlen, maxlines)
     {
         var html = Q(String(str));
 
         // limit visible text length
         if (maxlen) {
             var morelink = '<span>... <a href="#more" onclick="$(this).parent().hide().next().show();return false" class="morelink">'+rcmail.gettext('showmore','libcalendaring')+'</a></span><span style="display:none">',
                 lines = html.split(/\r?\n/),
                 words, out = '', len = 0;
 
             for (var i=0; i < lines.length; i++) {
                 len += lines[i].length;
                 if (maxlines && i == maxlines - 1) {
                     out += lines[i] + '\n' + morelink;
                     maxlen = html.length * 2;
                 }
                 else if (len > maxlen) {
                     len = out.length;
                     words = lines[i].split(' ');
                     for (var j=0; j < words.length; j++) {
                         len += words[j].length + 1;
                         out += words[j] + ' ';
                         if (len > maxlen) {
                             out += morelink;
                             maxlen = html.length * 2;
                             maxlines = 0;
                         }
                     }
                     out += '\n';
                 }
                 else
                     out += lines[i] + '\n';
             }
 
             if (maxlen > str.length)
                 out += '</span>';
 
             html = out;
         }
 
         // simple link parser (similar to rcube_string_replacer class in PHP)
         var utf_domain = '[^?&@"\'/\\(\\)\\s\\r\\t\\n]+\\.([^\x00-\x2f\x3b-\x40\x5b-\x60\x7b-\x7f]{2,}|xn--[a-z0-9]{2,})';
         var url1 = '.:;,', url2 = 'a-z0-9%=#@+?&/_~\\[\\]-';
         var link_pattern = new RegExp('([hf]t+ps?://)('+utf_domain+'(['+url1+']?['+url2+']+)*)', 'ig');
         var mailto_pattern = new RegExp('([^\\s\\n\\(\\);]+@'+utf_domain+')', 'ig');
         var link_replace = function(matches, p1, p2) {
           var title = '', text = p2;
           if (p2 && p2.length > 55) {
             text = p2.substr(0, 45) + '...' + p2.substr(-8);
             title = p1 + p2;
           }
           return '<a href="'+p1+p2+'" class="extlink" target="_blank" title="'+title+'">'+p1+text+'</a>'
         };
 
         return html
             .replace(link_pattern, link_replace)
             .replace(mailto_pattern, '<a href="mailto:$1">$1</a>')
             .replace(/(mailto:)([^"]+)"/g, '$1$2" onclick="rcmail.command(\'compose\', \'$2\');return false"')
             .replace(/\n/g, "<br/>");
     };
 
     this.init_alarms_edit = function(prefix, index)
     {
         var edit_type = $(prefix+' select.edit-alarm-type'),
           dom_id = edit_type.attr('id');
 
         // register events on alarm fields
         edit_type.change(function(){
             $(this).parent().find('span.edit-alarm-values')[(this.selectedIndex>0?'show':'hide')]();
         });
         $(prefix+' select.edit-alarm-offset').change(function(){
             var val = $(this).val(), parent = $(this).parent();
             parent.find('.edit-alarm-date, .edit-alarm-time')[val == '@' ? 'show' : 'hide']();
             parent.find('.edit-alarm-value').prop('disabled', val === '@' || val === '0');
             parent.find('.edit-alarm-related')[val == '@' ? 'hide' : 'show']();
         });
 
         $(prefix+' .edit-alarm-date').removeClass('hasDatepicker').removeAttr('id').datepicker(datepicker_settings);
 
         $(prefix).on('click', 'a.delete-alarm', function(e){
             if ($(this).closest('.edit-alarm-item').siblings().length > 0) {
                 $(this).closest('.edit-alarm-item').remove();
             }
             return false;
         });
 
         // set a unique id attribute and set label reference accordingly
         if ((index || 0) > 0 && dom_id) {
             dom_id += ':' + (new Date().getTime());
             edit_type.attr('id', dom_id);
             $(prefix+' label:first').attr('for', dom_id);
         }
 
         $(prefix).on('click', 'a.add-alarm', function(e){
             var i = $(this).closest('.edit-alarm-item').siblings().length + 1;
             var item = $(this).closest('.edit-alarm-item').clone(false)
               .removeClass('first')
               .appendTo(prefix);
 
               me.init_alarms_edit(prefix + ' .edit-alarm-item:eq(' + i + ')', i);
               $('select.edit-alarm-type, select.edit-alarm-offset', item).change();
               return false;
         });
     }
 
     this.set_alarms_edit = function(prefix, valarms)
     {
         $(prefix + ' .edit-alarm-item:gt(0)').remove();
 
         var i, alarm, domnode, val, offset;
         for (i=0; i < valarms.length; i++) {
           alarm = valarms[i];
           if (!alarm.action)
               alarm.action = 'DISPLAY';
 
           if (i == 0) {
               domnode = $(prefix + ' .edit-alarm-item').eq(0);
           }
           else {
               domnode = $(prefix + ' .edit-alarm-item').eq(0).clone(false).removeClass('first').appendTo(prefix);
               this.init_alarms_edit(prefix + ' .edit-alarm-item:eq(' + i + ')', i);
           }
 
           $('select.edit-alarm-type', domnode).val(alarm.action);
           $('select.edit-alarm-related', domnode).val(/END/i.test(alarm.related) ? 'end' : 'start');
 
           if (String(alarm.trigger).match(/@(\d+)/)) {
               var ondate = this.fromunixtime(parseInt(RegExp.$1));
               $('select.edit-alarm-offset', domnode).val('@');
               $('input.edit-alarm-value', domnode).val('');
               $('input.edit-alarm-date', domnode).val(this.format_datetime(ondate, 1));
               $('input.edit-alarm-time', domnode).val(this.format_datetime(ondate, 2));
           }
           else if (String(alarm.trigger).match(/^[-+]*0[MHDS]$/)) {
               $('input.edit-alarm-value', domnode).val('0');
               $('select.edit-alarm-offset', domnode).val('0');
           }
           else if (String(alarm.trigger).match(/([-+])(\d+)([MHDS])/)) {
               val = RegExp.$2; offset = ''+RegExp.$1+RegExp.$3;
               $('input.edit-alarm-value', domnode).val(val);
               $('select.edit-alarm-offset', domnode).val(offset);
           }
         }
 
         // set correct visibility by triggering onchange handlers
         $(prefix + ' select.edit-alarm-type, ' + prefix + ' select.edit-alarm-offset').change();
     };
 
     this.serialize_alarms = function(prefix)
     {
         var valarms = [];
 
         $(prefix + ' .edit-alarm-item').each(function(i, elem) {
             var val, offset, alarm = {
                     action: $('select.edit-alarm-type', elem).val(),
                     related: $('select.edit-alarm-related', elem).val()
                 };
 
             if (alarm.action) {
                 offset = $('select.edit-alarm-offset', elem).val();
                 if (offset == '@') {
                     alarm.trigger = '@' + me.date2unixtime(me.parse_datetime($('input.edit-alarm-time', elem).val(), $('input.edit-alarm-date', elem).val()));
                 }
                 else if (offset === '0') {
                     alarm.trigger = '0S';
                 }
                 else if (!isNaN((val = parseInt($('input.edit-alarm-value', elem).val()))) && val >= 0) {
                     alarm.trigger = offset[0] + val + offset[1];
                 }
 
                 valarms.push(alarm);
             }
         });
 
         return valarms;
     };
 
     // format time string
     var time_autocomplete_format = function(hour, minutes, start) {
         var time, diff, unit, duration = '', d = new Date();
 
         d.setHours(hour);
         d.setMinutes(minutes);
         time = me.format_time(d);
 
         if (start) {
             diff = Math.floor((d.getTime() - start.getTime()) / 60000);
             if (diff > 0) {
                 unit = 'm';
                 if (diff >= 60) {
                     unit = 'h';
                     diff = Math.round(diff / 3) / 20;
                 }
                 duration = ' (' + diff + unit + ')';
             }
         }
 
         return [time, duration];
     };
 
     var time_autocomplete_list = function(p, callback) {
         // Time completions
         var st, h, step = 15, result = [], now = new Date(),
             id = String(this.element.attr('id')),
             m = id.match(/^(.*)-(starttime|endtime)$/),
             start = (m && m[2] == 'endtime'
                 && (st = $('#' + m[1] + '-starttime').val())
                 && $('#' + m[1] + '-startdate').val() == $('#' + m[1] + '-enddate').val())
                 ? me.parse_datetime(st, '') : null,
             full = p.term - 1 > 0 || p.term.length > 1,
             hours = start ? start.getHours() : (full ? me.parse_datetime(p.term, '') : now).getHours(),
             minutes = hours * 60 + (full ? 0 : now.getMinutes()),
             min = Math.ceil(minutes / step) * step % 60,
             hour = Math.floor(Math.ceil(minutes / step) * step / 60);
 
         // list hours from 0:00 till now
         for (h = start ? start.getHours() : 0; h < hours; h++)
             result.push(time_autocomplete_format(h, 0, start));
 
         // list 15min steps for the next two hours
         for (; h < hour + 2 && h < 24; h++) {
             while (min < 60) {
                 result.push(time_autocomplete_format(h, min, start));
                 min += step;
             }
             min = 0;
         }
 
         // list the remaining hours till 23:00
         while (h < 24)
             result.push(time_autocomplete_format((h++), 0, start));
 
         return callback(result);
     };
 
     var time_autocomplete_open = function(event, ui) {
         // scroll to current time
         var $this = $(this),
             widget = $this.autocomplete('widget')
             menu = $this.data('ui-autocomplete').menu,
             amregex = /^(.+)(a[.m]*)/i,
             pmregex = /^(.+)(a[.m]*)/i,
             val = $(this).val().replace(amregex, '0:$1').replace(pmregex, '1:$1');
 
         widget.css('width', '10em');
 
         if (val === '')
             menu._scrollIntoView(widget.children('li:first'));
         else
             widget.children().each(function() {
                 var li = $(this),
                     html = li.children().first().html()
                         .replace(/\s+\(.+\)$/, '')
                         .replace(amregex, '0:$1')
                         .replace(pmregex, '1:$1');
 
                 if (html.indexOf(val) == 0)
                     menu._scrollIntoView(li);
             });
     };
 
     /**
      * Initializes time autocompletion
      */
     this.init_time_autocomplete = function(elem, props)
     {
         var default_props = {
                 delay: 100,
                 minLength: 1,
                 appendTo: props.container,
                 source: time_autocomplete_list,
                 open: time_autocomplete_open,
                 // change: time_autocomplete_change,
                 select: function(event, ui) {
                     $(this).val(ui.item[0]).change();
                     return false;
                 }
             };
 
         $(elem).attr('autocomplete', "off")
             .autocomplete($.extend(default_props, props))
             .click(function() {  // show drop-down upon clicks
                 $(this).autocomplete('search', $(this).val() ? $(this).val().replace(/\D.*/, "") : " ");
             });
 
         $(elem).data('ui-autocomplete')._renderItem = function(ul, item) {
             return $('<li>')
                 .data('ui-autocomplete-item', item)
                 .append('<a>' + item[0] + item[1] + '</a>')
                 .appendTo(ul);
         };
     };
 
     /*****  Alarms handling  *****/
 
     /**
      * Display a notification for the given pending alarms
      */
     this.display_alarms = function(alarms)
     {
         // clear old alert first
         if (this.alarm_dialog)
             this.alarm_dialog.dialog('destroy').remove();
 
         var i, actions, adismiss, asnooze, alarm, html,
             audio_alarms = [], records = [], event_ids = [], buttons = {};
 
         for (i=0; i < alarms.length; i++) {
             alarm = alarms[i];
             alarm.start = this.parseISO8601(alarm.start);
             alarm.end = this.parseISO8601(alarm.end);
 
             if (alarm.action == 'AUDIO') {
                 audio_alarms.push(alarm);
                 continue;
             }
 
             event_ids.push(alarm.id);
 
             html = '<h3 class="event-title">' + Q(alarm.title) + '</h3>';
             html += '<div class="event-section">' + Q(alarm.location || '') + '</div>';
             html += '<div class="event-section">' + Q(this.event_date_text(alarm)) + '</div>';
 
             adismiss = $('<a href="#" class="alarm-action-dismiss"></a>').html(rcmail.gettext('dismiss','libcalendaring')).click(function(e){
                 me.dismiss_link = $(this);
                 me.dismiss_alarm(me.dismiss_link.data('id'), 0, e);
             });
             asnooze = $('<a href="#" class="alarm-action-snooze"></a>').html(rcmail.gettext('snooze','libcalendaring')).click(function(e){
                 me.snooze_dropdown($(this), e);
                 e.stopPropagation();
                 return false;
             });
             actions = $('<div>').addClass('alarm-actions').append(adismiss.data('id', alarm.id)).append(asnooze.data('id', alarm.id));
 
             records.push($('<div>').addClass('alarm-item').html(html).append(actions));
         }
 
         if (audio_alarms.length)
             this.audio_alarms(audio_alarms);
 
         if (!records.length)
             return;
 
         this.alarm_dialog = $('<div>').attr('id', 'alarm-display').append(records);
 
         buttons[rcmail.gettext('close')] = function() {
             $(this).dialog('close');
         };
 
         buttons[rcmail.gettext('dismissall','libcalendaring')] = function(e) {
             // submit dismissed event_ids to server
             me.dismiss_alarm(me.alarm_ids.join(','), 0, e);
             $(this).dialog('close');
         };
 
         this.alarm_dialog.appendTo(document.body).dialog({
             modal: false,
             resizable: true,
             closeOnEscape: false,
             dialogClass: 'alarms',
             title: rcmail.gettext('alarmtitle','libcalendaring'),
             buttons: buttons,
             open: function() {
               setTimeout(function() {
                 me.alarm_dialog.parent().find('.ui-button:not(.ui-dialog-titlebar-close)').first().focus();
               }, 5);
             },
             close: function() {
               $('#alarm-snooze-dropdown').hide();
               $(this).dialog('destroy').remove();
               me.alarm_dialog = null;
               me.alarm_ids = null;
             },
             drag: function(event, ui) {
               $('#alarm-snooze-dropdown').hide();
             }
         });
 
         this.alarm_dialog.closest('div[role=dialog]').attr('role', 'alertdialog');
 
         this.alarm_ids = event_ids;
     };
 
     /**
      * Display a notification and play a sound for a set of alarms
      */
     this.audio_alarms = function(alarms)
     {
         var elem, txt = [],
             src = rcmail.assets_path('plugins/libcalendaring/alarm'),
             plugin = navigator.mimeTypes ? navigator.mimeTypes['audio/mp3'] : {};
 
         // first generate and display notification text
         $.each(alarms, function() { txt.push(this.title); });
 
         rcmail.display_message(rcmail.gettext('alarmtitle','libcalendaring') + ': ' + Q(txt.join(', ')), 'notice', 10000);
 
         // Internet Explorer does not support wav files,
         // support in other browsers depends on enabled plugins,
         // so we use wav as a fallback
         src += bw.ie || (plugin && plugin.enabledPlugin) ? '.mp3' : '.wav';
 
         // HTML5
         try {
             elem = $('<audio>').attr('src', src);
             elem.get(0).play();
         }
         // old method
         catch (e) {
             elem = $('<embed id="libcalsound" src="' + src + '" hidden=true autostart=true loop=false />');
             elem.appendTo($('body'));
             window.setTimeout("$('#libcalsound').remove()", 10000);
         }
     };
 
     /**
      * Show a drop-down menu with a selection of snooze times
      */
     this.snooze_dropdown = function(link, event)
     {
         if (!this.snooze_popup) {
             this.snooze_popup = $('#alarm-snooze-dropdown');
             // create popup if not found
             if (!this.snooze_popup.length) {
                 this.snooze_popup = $('<div>').attr('id', 'alarm-snooze-dropdown').addClass('popupmenu').appendTo(document.body);
                 this.snooze_popup.html(rcmail.env.snooze_select)
             }
             $('#alarm-snooze-dropdown a').click(function(e){
                 var time = String(this.href).replace(/.+#/, '');
                 me.dismiss_alarm($('#alarm-snooze-dropdown').data('id'), time, e);
                 return false;
             });
         }
 
         // hide visible popup
         if (this.snooze_popup.is(':visible') && this.snooze_popup.data('id') == link.data('id')) {
             rcmail.command('menu-close', 'alarm-snooze-dropdown', link.get(0), event);
             this.dismiss_link = null;
         }
         else {  // open popup below the clicked link
             rcmail.command('menu-open', 'alarm-snooze-dropdown', link.get(0), event);
             this.snooze_popup.data('id', link.data('id'));
             this.dismiss_link = link;
         }
     };
 
     /**
      * Dismiss or snooze alarms for the given event
      */
     this.dismiss_alarm = function(id, snooze, event)
     {
         rcmail.command('menu-close', 'alarm-snooze-dropdown', null, event);
         rcmail.http_post('utils/plugin.alarms', { action:'dismiss', data:{ id:id, snooze:snooze } });
 
         // remove dismissed alarm from list
         if (this.dismiss_link) {
             this.dismiss_link.closest('div.alarm-item').hide();
             var new_ids = jQuery.grep(this.alarm_ids, function(v){ return v != id; });
             if (new_ids.length)
                 this.alarm_ids = new_ids;
             else
                 this.alarm_dialog.dialog('close');
         }
 
         this.dismiss_link = null;
     };
 
 
     /*****  Recurrence form handling  *****/
 
     /**
      * Install event handlers on recurrence form elements
      */
     this.init_recurrence_edit = function(prefix)
     {
         // toggle recurrence frequency forms
         $('#edit-recurrence-frequency').change(function(e){
             var freq = $(this).val().toLowerCase();
             $('.recurrence-form').hide();
             if (freq) {
               $('#recurrence-form-'+freq).show();
               if (freq != 'rdate')
                 $('#recurrence-form-until').show();
             }
         });
         $('#recurrence-form-rdate input.button.add').click(function(e){
             var dt, dv = $('#edit-recurrence-rdate-input').val();
             if (dv && (dt = me.parse_datetime('12:00', dv))) {
                 me.add_rdate(dt);
                 me.sort_rdates();
                 $('#edit-recurrence-rdate-input').val('')
             }
             else {
                 $('#edit-recurrence-rdate-input').select();
             }
         });
         $('#edit-recurrence-rdates').on('click', 'a.delete', function(e){
             $(this).closest('li').remove();
             return false;
         });
 
         $('#edit-recurrence-enddate').datepicker(datepicker_settings).click(function(){ $("#edit-recurrence-repeat-until").prop('checked', true) });
         $('#edit-recurrence-repeat-times').change(function(e){ $('#edit-recurrence-repeat-count').prop('checked', true); });
         $('#edit-recurrence-rdate-input').datepicker(datepicker_settings);
     };
 
     /**
      * Set recurrence form according to the given event/task record
      */
     this.set_recurrence_edit = function(rec)
     {
         var recurrence = $('#edit-recurrence-frequency').val(rec.recurrence ? rec.recurrence.FREQ || (rec.recurrence.RDATE ? 'RDATE' : '') : '').change(),
             interval = $('.recurrence-form select.edit-recurrence-interval').val(rec.recurrence ? rec.recurrence.INTERVAL || 1 : 1),
             rrtimes = $('#edit-recurrence-repeat-times').val(rec.recurrence ? rec.recurrence.COUNT || 1 : 1),
             rrenddate = $('#edit-recurrence-enddate').val(rec.recurrence && rec.recurrence.UNTIL ? this.format_datetime(this.parseISO8601(rec.recurrence.UNTIL), 1) : '');
         $('.recurrence-form input.edit-recurrence-until:checked').prop('checked', false);
         $('#edit-recurrence-rdates').html('');
 
         var weekdays = ['SU','MO','TU','WE','TH','FR','SA'],
             rrepeat_id = '#edit-recurrence-repeat-forever';
         if      (rec.recurrence && rec.recurrence.COUNT) rrepeat_id = '#edit-recurrence-repeat-count';
         else if (rec.recurrence && rec.recurrence.UNTIL) rrepeat_id = '#edit-recurrence-repeat-until';
         $(rrepeat_id).prop('checked', true);
 
         if (rec.recurrence && rec.recurrence.BYDAY && rec.recurrence.FREQ == 'WEEKLY') {
             var wdays = rec.recurrence.BYDAY.split(',');
             $('input.edit-recurrence-weekly-byday').val(wdays);
         }
         if (rec.recurrence && rec.recurrence.BYMONTHDAY) {
             $('input.edit-recurrence-monthly-bymonthday').val(String(rec.recurrence.BYMONTHDAY).split(','));
             $('input.edit-recurrence-monthly-mode').val(['BYMONTHDAY']);
         }
         if (rec.recurrence && rec.recurrence.BYDAY && (rec.recurrence.FREQ == 'MONTHLY' || rec.recurrence.FREQ == 'YEARLY')) {
             var byday, section = rec.recurrence.FREQ.toLowerCase();
             if ((byday = String(rec.recurrence.BYDAY).match(/(-?[1-4])([A-Z]+)/))) {
                 $('#edit-recurrence-'+section+'-prefix').val(byday[1]);
                 $('#edit-recurrence-'+section+'-byday').val(byday[2]);
             }
             $('input.edit-recurrence-'+section+'-mode').val(['BYDAY']);
         }
         else if (rec.start) {
             $('#edit-recurrence-monthly-byday').val(weekdays[rec.start.getDay()]);
         }
         if (rec.recurrence && rec.recurrence.BYMONTH) {
             $('input.edit-recurrence-yearly-bymonth').val(String(rec.recurrence.BYMONTH).split(','));
         }
         else if (rec.start) {
             $('input.edit-recurrence-yearly-bymonth').val([String(rec.start.getMonth()+1)]);
         }
         if (rec.recurrence && rec.recurrence.RDATE) {
             $.each(rec.recurrence.RDATE, function(i,rdate){
                 me.add_rdate(me.parseISO8601(rdate));
             });
         }
     };
 
     /**
      * Gather recurrence settings from form
      */
     this.serialize_recurrence = function(timestr)
     {
         var recurrence = '',
             freq = $('#edit-recurrence-frequency').val();
 
         if (freq != '') {
             recurrence = {
                 FREQ: freq,
                 INTERVAL: $('#edit-recurrence-interval-'+freq.toLowerCase()).val()
             };
 
             var until = $('input.edit-recurrence-until:checked').val();
             if (until == 'count')
                 recurrence.COUNT = $('#edit-recurrence-repeat-times').val();
             else if (until == 'until')
                 recurrence.UNTIL = me.date2ISO8601(me.parse_datetime(timestr || '00:00', $('#edit-recurrence-enddate').val()));
 
             if (freq == 'WEEKLY') {
                 var byday = [];
                 $('input.edit-recurrence-weekly-byday:checked').each(function(){ byday.push(this.value); });
                 if (byday.length)
                     recurrence.BYDAY = byday.join(',');
             }
             else if (freq == 'MONTHLY') {
                 var mode = $('input.edit-recurrence-monthly-mode:checked').val(), bymonday = [];
                 if (mode == 'BYMONTHDAY') {
                     $('input.edit-recurrence-monthly-bymonthday:checked').each(function(){ bymonday.push(this.value); });
                     if (bymonday.length)
                         recurrence.BYMONTHDAY = bymonday.join(',');
                 }
                 else
                     recurrence.BYDAY = $('#edit-recurrence-monthly-prefix').val() + $('#edit-recurrence-monthly-byday').val();
             }
             else if (freq == 'YEARLY') {
                 var byday, bymonth = [];
                 $('input.edit-recurrence-yearly-bymonth:checked').each(function(){ bymonth.push(this.value); });
                 if (bymonth.length)
                     recurrence.BYMONTH = bymonth.join(',');
                 if ((byday = $('#edit-recurrence-yearly-byday').val()))
                     recurrence.BYDAY = $('#edit-recurrence-yearly-prefix').val() + byday;
             }
             else if (freq == 'RDATE') {
                 recurrence = { RDATE:[] };
                 // take selected but not yet added date into account
                 if ($('#edit-recurrence-rdate-input').val() != '') {
                     $('#recurrence-form-rdate input.button.add').click();
                 }
                 $('#edit-recurrence-rdates li').each(function(i, li){
                     recurrence.RDATE.push($(li).attr('data-value'));
                 });
             }
         }
 
         return recurrence;
     };
 
     // add the given date to the RDATE list
     this.add_rdate = function(date)
     {
         var li = $('<li>')
             .attr('data-value', this.date2ISO8601(date))
             .html('<span>' + Q(this.format_datetime(date, 1)) + '</span>')
             .appendTo('#edit-recurrence-rdates');
 
         $('<a>').attr('href', '#del')
             .addClass('iconbutton delete')
             .html(rcmail.get_label('delete', 'libcalendaring'))
             .attr('title', rcmail.get_label('delete', 'libcalendaring'))
             .appendTo(li);
     };
 
     // re-sort the list items by their 'data-value' attribute
     this.sort_rdates = function()
     {
         var mylist = $('#edit-recurrence-rdates'),
             listitems = mylist.children('li').get();
         listitems.sort(function(a, b) {
             var compA = $(a).attr('data-value');
             var compB = $(b).attr('data-value');
             return (compA < compB) ? -1 : (compA > compB) ? 1 : 0;
         })
         $.each(listitems, function(idx, item) { mylist.append(item); });
     };
 
 
     /*****  Attendee form handling  *****/
 
     // expand the given contact group into individual event/task attendees
     this.expand_attendee_group = function(e, add, remove)
     {
         var id = (e.data ? e.data.email : null) || $(e.target).attr('data-email'),
             role_select = $(e.target).closest('tr').find('select.edit-attendee-role option:selected');
 
         this.group2expand[id] = { link: e.target, data: $.extend({}, e.data || {}), adder: add, remover: remove }
 
         // copy group role from the according form element
         if (role_select.length) {
             this.group2expand[id].data.role = role_select.val();
         }
 
         // register callback handler
         if (!this._expand_attendee_listener) {
             this._expand_attendee_listener = this.expand_attendee_callback;
             rcmail.addEventListener('plugin.expand_attendee_callback', function(result) {
                 me._expand_attendee_listener(result);
             });
         }
 
         rcmail.http_post('libcal/plugin.expand_attendee_group', { id: id, data: e.data || {} }, rcmail.set_busy(true, 'loading'));
     };
 
     // callback from server to expand an attendee group
     this.expand_attendee_callback = function(result)
     {
         var attendee, id = result.id,
             data = this.group2expand[id],
             row = $(data.link).closest('tr');
 
         // replace group entry with all members returned by the server
         if (data && data.adder && result.members && result.members.length) {
             for (var i=0; i < result.members.length; i++) {
                 attendee = result.members[i];
                 attendee.role = data.data.role;
                 attendee.cutype = 'INDIVIDUAL';
                 attendee.status = 'NEEDS-ACTION';
                 data.adder(attendee, null, row);
             }
 
             if (data.remover) {
                 data.remover(data.link, id)
             }
             else {
                 row.remove();
             }
 
             delete this.group2expand[id];
         }
         else {
             rcmail.display_message(result.error || rcmail.gettext('expandattendeegroupnodata','libcalendaring'), 'error');
         }
     };
 
 
     // Render message reference links to the given container
     this.render_message_links = function(links, container, edit, plugin)
     {
         var ul = $('<ul>').addClass('attachmentslist');
 
         $.each(links, function(i, link) {
             if (!link.mailurl)
                 return true;  // continue
 
             var li = $('<li>').addClass('link')
                 .addClass('message eml')
                 .append($('<a>')
                     .attr('href', link.mailurl)
                     .addClass('messagelink')
                     .text(link.subject || link.uri)
                 )
                 .appendTo(ul);
 
             // add icon to remove the link
             if (edit) {
                 $('<a>')
                     .attr('href', '#delete')
                     .attr('title', rcmail.gettext('removelink', plugin))
                     .attr('data-uri', link.uri)
                     .addClass('delete')
                     .text(rcmail.gettext('delete'))
                     .appendTo(li);
             }
         });
 
         container.empty().append(ul);
     }
 
     // resize and reposition (center) the dialog window
     this.dialog_resize = function(id, height, width)
     {
         var win = $(window), w = win.width(), h = win.height();
 
         $(id).dialog('option', {
             height: Math.min(h-20, height+130),
             width: Math.min(w-20, width+50)
         })
         .dialog('option', 'position', ['center', 'center']);  // only works in a separate call (!?)
     };
 }
 
 //////  static methods
 
 // render HTML code for displaying an attendee record
 rcube_libcalendaring.attendee_html = function(data)
 {
     var name, tooltip = '', context = 'libcalendaring',
         dispname = data.name || data.email,
         status = data.role == 'ORGANIZER' ? 'ORGANIZER' : data.status;
 
     if (status)
         status = status.toLowerCase();
 
     if (data.email) {
         tooltip = data.email;
         name = $('<a>').attr({href: 'mailto:' + data.email, 'class': 'mailtolink', 'data-cutype': data.cutype})
 
         if (status)
             tooltip += ' (' + rcmail.gettext('status' + status, context) + ')';
     }
     else {
         name = $('<span>');
     }
 
     if (data['delegated-to'])
         tooltip = rcmail.gettext('delegatedto', context) + ' ' + data['delegated-to'];
     else if (data['delegated-from'])
         tooltip = rcmail.gettext('delegatedfrom', context) + ' ' + data['delegated-from'];
 
     return $('<span>').append(
             $('<span>').attr({'class': 'attendee ' + status, title: tooltip}).append(name.text(dispname))
         ).html();
 };
 
 /**
  *
  */
 rcube_libcalendaring.add_from_itip_mail = function(mime_id, task, status, dom_id)
 {
     // ask user to delete the declined event from the local calendar (#1670)
     var del = false;
     if (rcmail.env.rsvp_saved && status == 'declined') {
         del = confirm(rcmail.gettext('itip.declinedeleteconfirm'));
     }
 
     // open dialog for iTip delegation
     if (status == 'delegated') {
         rcube_libcalendaring.itip_delegate_dialog(function(data) {
             rcmail.http_post(task + '/itip-delegate', {
                 _uid: rcmail.env.uid,
                 _mbox: rcmail.env.mailbox,
                 _part: mime_id,
                 _to: data.to,
                 _rsvp: data.rsvp ? 1 : 0,
                 _comment: data.comment,
                 _folder: data.target
             }, rcmail.set_busy(true, 'itip.savingdata'));
         }, $('#rsvp-'+dom_id+' .folder-select'));
         return false;
     }
 
     var noreply = 0, comment = '';
     if (dom_id) {
       noreply = $('#noreply-'+dom_id+':checked').length ? 1 : 0;
       if (!noreply)
         comment = $('#reply-comment-'+dom_id).val();
     }
 
     rcmail.http_post(task + '/mailimportitip', {
         _uid: rcmail.env.uid,
         _mbox: rcmail.env.mailbox,
         _part: mime_id,
         _folder: $('#itip-saveto').val(),
         _status: status,
         _del: del?1:0,
         _noreply: noreply,
         _comment: comment
       }, rcmail.set_busy(true, 'itip.savingdata'));
 
     return false;
 };
 
 /**
  * Helper function to render the iTip delegation dialog
  * and trigger a callback function when submitted.
  */
 rcube_libcalendaring.itip_delegate_dialog = function(callback, selector)
 {
     // show dialog for entering the delegatee address and comment
     var html = '<form class="itip-dialog-form" action="javascript:void()">' +
         '<div class="form-section">' +
             '<label for="itip-delegate-to">' + rcmail.gettext('itip.delegateto') + '</label><br/>' +
             '<input type="text" id="itip-delegate-to" class="text" size="40" value="" />' +
         '</div>' +
         '<div class="form-section">' +
             '<label for="itip-delegate-rsvp">' +
                 '<input type="checkbox" id="itip-delegate-rsvp" class="checkbox" size="40" value="" />' +
                 rcmail.gettext('itip.delegatersvpme') +
             '</label>' +
         '</div>' +
         '<div class="form-section">' +
             '<textarea id="itip-delegate-comment" class="itip-comment" cols="40" rows="8" placeholder="' +
                 rcmail.gettext('itip.itipcomment') + '"></textarea>' + 
         '</div>' +
         '<div class="form-section">' +
             (selector && selector.length ? selector.html() : '') +
         '</div>' +
     '</form>';
 
     var dialog, buttons = [];
     buttons.push({
         text: rcmail.gettext('itipdelegated', 'itip'),
         click: function() {
             var doc = window.parent.document,
                 delegatee = String($('#itip-delegate-to', doc).val()).replace(/(^\s+)|(\s+$)/, '');
 
             if (delegatee != '' && rcube_check_email(delegatee, true)) {
                 callback({
                     to: delegatee,
                     rsvp: $('#itip-delegate-rsvp', doc).prop('checked'),
                     comment: $('#itip-delegate-comment', doc).val(),
                     target: $('#itip-saveto', doc).val()
                 });
 
                 setTimeout(function() { dialog.dialog("close"); }, 500);
             }
             else {
                 alert(rcmail.gettext('itip.delegateinvalidaddress'));
                 $('#itip-delegate-to', doc).focus();
             }
         }
     });
 
     buttons.push({
         text: rcmail.gettext('cancel', 'itip'),
         click: function() {
             dialog.dialog('close');
         }
     });
 
     dialog = rcmail.show_popup_dialog(html, rcmail.gettext('delegateinvitation', 'itip'), buttons, {
         width: 460,
         open: function(event, ui) {
             $(this).parent().find('.ui-button:not(.ui-dialog-titlebar-close)').first().addClass('mainaction');
             $(this).find('#itip-saveto').val('');
 
             // initialize autocompletion
             var ac_props, rcm = rcmail.is_framed() ? parent.rcmail : rcmail;
             if (rcmail.env.autocomplete_threads > 0) {
                 ac_props = {
                     threads: rcmail.env.autocomplete_threads,
                     sources: rcmail.env.autocomplete_sources
                 };
             }
             rcm.init_address_input_events($(this).find('#itip-delegate-to').focus(), ac_props);
             rcm.env.recipients_delimiter = '';
         },
         close: function(event, ui) {
             rcm = rcmail.is_framed() ? parent.rcmail : rcmail;
             rcm.ksearch_blur();
             $(this).remove();
         }
     });
 
     return dialog;
 };
 
 /**
  * Show a menu for selecting the RSVP reply mode
  */
 rcube_libcalendaring.itip_rsvp_recurring = function(btn, callback)
 {
     var mnu = $('<ul></ul>').addClass('popupmenu libcal-rsvp-replymode');
 
     $.each(['all','current'/*,'future'*/], function(i, mode) {
         $('<li><a>' + rcmail.get_label('rsvpmode'+mode, 'libcalendaring') + '</a>')
         .addClass('ui-menu-item')
         .attr('rel', mode)
         .appendTo(mnu);
     });
 
     var action = btn.attr('rel');
 
     // open the mennu
     mnu.menu({
         select: function(event, ui) {
             callback(action, ui.item.attr('rel'));
         }
     })
     .appendTo(document.body)
     .position({ my: 'left top', at: 'left bottom+2', of: btn })
     .data('action', action);
 
     setTimeout(function() {
         $(document).one('click', function() {
             mnu.menu('destroy');
             mnu.remove();
         });
     }, 100);
 };
 
 /**
  *
  */
 rcube_libcalendaring.remove_from_itip = function(event, task, title)
 {
     if (confirm(rcmail.gettext('itip.deleteobjectconfirm').replace('$title', title))) {
         rcmail.http_post(task + '/itip-remove',
             event,
             rcmail.set_busy(true, 'itip.savingdata')
         );
     }
 };
 
 /**
  *
  */
 rcube_libcalendaring.decline_attendee_reply = function(mime_id, task)
 {
     // show dialog for entering a comment and send to server
     var html = '<div class="itip-dialog-confirm-text">' + rcmail.gettext('itip.declineattendeeconfirm') + '</div>' +
         '<textarea id="itip-decline-comment" class="itip-comment" cols="40" rows="8"></textarea>';
 
     var dialog, buttons = [];
     buttons.push({
         text: rcmail.gettext('declineattendee', 'itip'),
         click: function() {
             rcmail.http_post(task + '/itip-decline-reply', {
                 _uid: rcmail.env.uid,
                 _mbox: rcmail.env.mailbox,
                 _part: mime_id,
                 _comment: $('#itip-decline-comment', window.parent.document).val()
             }, rcmail.set_busy(true, 'itip.savingdata'));
           dialog.dialog("close");
         }
     });
 
     buttons.push({
         text: rcmail.gettext('cancel', 'itip'),
         click: function() {
           dialog.dialog('close');
         }
     });
 
     dialog = rcmail.show_popup_dialog(html, rcmail.gettext('declineattendee', 'itip'), buttons, {
         width: 460,
         open: function() {
             $(this).parent().find('.ui-button:not(.ui-dialog-titlebar-close)').first().addClass('mainaction');
             $('#itip-decline-comment').focus();
         }
     });
 
     return false;
 };
 
 /**
  *
  */
 rcube_libcalendaring.fetch_itip_object_status = function(p)
 {
+  p.mbox = rcmail.env.mailbox;
+  p.message_uid = rcmail.env.uid;
   rcmail.http_post(p.task + '/itip-status', { data: p });
 };
 
 /**
  *
  */
 rcube_libcalendaring.update_itip_object_status = function(p)
 {
   rcmail.env.rsvp_saved = p.saved;
   rcmail.env.itip_existing = p.existing;
 
   // hide all elements first
   $('#itip-buttons-'+p.id+' > div').hide();
   $('#rsvp-'+p.id+' .folder-select').remove();
 
   if (p.html) {
     // append/replace rsvp status display
     $('#loading-'+p.id).next('.rsvp-status').remove();
     $('#loading-'+p.id).hide().after(p.html);
   }
 
   // enable/disable rsvp buttons
   if (p.action == 'rsvp') {
     $('#rsvp-'+p.id+' input.button').prop('disabled', false)
       .filter('.'+String(p.status||'unknown').toLowerCase()).prop('disabled', p.latest);
   }
 
   // show rsvp/import buttons (with calendar selector)
   $('#'+p.action+'-'+p.id).show().find('input.button').last().after(p.select);
 
   // highlight date if date change detected
-  if (p.resheduled)
+  if (p.rescheduled)
     $('.calendar-eventdetails td.date').addClass('modified');
 
   // show itip box appendix after replacing the given placeholders
   if (p.append && p.append.selector) {
     var elem = $(p.append.selector);
     if (p.append.replacements) {
       $.each(p.append.replacements, function(k, html) {
         elem.html(elem.html().replace(k, html));
       });
     }
     else if (p.append.html) {
       elem.html(p.append.html)
     }
     elem.show();
   }
 };
 
 /**
  * Callback from server after an iTip message has been processed
  */
 rcube_libcalendaring.itip_message_processed = function(metadata)
 {
   if (metadata.after_action) {
     setTimeout(function(){ rcube_libcalendaring.itip_after_action(metadata.after_action); }, 1200);
   }
   else {
     rcube_libcalendaring.fetch_itip_object_status(metadata);
   }
 };
 
 /**
  * After-action on iTip request message. Action types:
  *     0 - no action
  *     1 - move to Trash
  *     2 - delete the message
  *     3 - flag as deleted
  *     folder_name - move the message to the specified folder
  */
 rcube_libcalendaring.itip_after_action = function(action)
 {
   if (!action) {
     return;
   }
 
   var rc = rcmail.is_framed() ? parent.rcmail : rcmail;
 
   if (action === 2) {
     rc.permanently_remove_messages();
   }
   else if (action === 3) {
     rc.mark_message('delete');
   }
   else {
     rc.move_messages(action === 1 ? rc.env.trash_mailbox : action);
   }
 };
 
 /**
  * Open the calendar preview for the current iTip event
  */
 rcube_libcalendaring.open_itip_preview = function(url, msgref)
 {
   if (!rcmail.env.itip_existing)
     url += '&itip=' + escape(msgref);
 
   var win = rcmail.open_window(url);
 };
 
 
 // extend jQuery
 (function($){
   $.fn.serializeJSON = function(){
     var json = {};
     jQuery.map($(this).serializeArray(), function(n, i) {
       json[n['name']] = n['value'];
     });
     return json;
   };
 })(jQuery);
 
 
 /* libcalendaring plugin initialization */
 window.rcmail && rcmail.addEventListener('init', function(evt) {
   if (rcmail.env.libcal_settings) {
     var libcal = new rcube_libcalendaring(rcmail.env.libcal_settings);
     rcmail.addEventListener('plugin.display_alarms', function(alarms){ libcal.display_alarms(alarms); });
   }
 
   rcmail.addEventListener('plugin.update_itip_object_status', rcube_libcalendaring.update_itip_object_status)
     .addEventListener('plugin.fetch_itip_object_status', rcube_libcalendaring.fetch_itip_object_status)
     .addEventListener('plugin.itip_message_processed', rcube_libcalendaring.itip_message_processed);
 
   if (rcmail.env.action == 'get-attachment' && rcmail.gui_objects['attachmentframe']) {
     rcmail.register_command('print-attachment', function() {
       var frame = rcmail.get_frame_window(rcmail.gui_objects['attachmentframe'].id);
       if (frame) frame.print();
     }, true);
   }
 
   if (rcmail.env.action == 'get-attachment' && rcmail.env.attachment_download_url) {
     rcmail.register_command('download-attachment', function() {
       rcmail.location_href(rcmail.env.attachment_download_url, window);
     }, true);
   }
 });