diff --git a/lib/file_manticore_api.php b/lib/file_manticore_api.php
index b590062..1a50712 100644
--- a/lib/file_manticore_api.php
+++ b/lib/file_manticore_api.php
@@ -1,440 +1,440 @@
 <?php
 /**
  +--------------------------------------------------------------------------+
  | This file is part of the Kolab File API                                  |
  |                                                                          |
  | Copyright (C) 2011-2015, Kolab Systems AG                                |
  |                                                                          |
  | 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/>      |
  +--------------------------------------------------------------------------+
  | Author: Aleksander Machniak <machniak@kolabsys.com>                      |
  +--------------------------------------------------------------------------+
 */
 
 /**
  * Helper class to connect to the Manticore API
  */
 class file_manticore_api
 {
     /**
      * @var HTTP_Request2
      */
     private $request;
 
     /**
      * @var string
      */
     private $base_url;
 
     /**
      * @var bool
      */
     private $debug = false;
 
     const ERROR_INTERNAL   = 100;
     const ERROR_CONNECTION = 500;
 
     const ACCEPT_HEADER = "application/json,text/javascript,*/*";
 
     const ACCESS_WRITE = 'write';
     const ACCESS_READ  = 'read';
     const ACCESS_DENY  = 'deny';
 
 
     /**
      * Class constructor.
      *
      * @param string $base_url Base URL of the Kolab API
      */
     public function __construct($base_url)
     {
         require_once 'HTTP/Request2.php';
 
         $config         = rcube::get_instance()->config;
         $this->debug    = rcube_utils::get_boolean($config->get('fileapi_manticore_debug'));
         $this->base_url = rtrim($base_url, '/') . '/';
         $this->request  = new HTTP_Request2();
 
         self::configure($this->request);
     }
 
     /**
      * Configure HTTP_Request2 object
      *
      * @param HTTP_Request2 $request Request object
      */
     public static function configure($request)
     {
         // Configure connection options
         $config      = rcube::get_instance()->config;
         $http_config = (array) $config->get('http_request', $config->get('kolab_http_request'));
 
         // Deprecated config, all options are separated variables
         if (empty($http_config)) {
             $options = array(
                 'ssl_verify_peer',
                 'ssl_verify_host',
                 'ssl_cafile',
                 'ssl_capath',
                 'ssl_local_cert',
                 'ssl_passphrase',
                 'follow_redirects',
             );
 
             foreach ($options as $optname) {
                 if (($optvalue = $config->get($optname)) !== null
                     || ($optvalue = $config->get('kolab_' . $optname)) !== null
                 ) {
                     $http_config[$optname] = $optvalue;
                 }
             }
         }
 
         if (!empty($http_config)) {
             try {
                 $request->setConfig($http_config);
             }
             catch (Exception $e) {
-                rcube::log_error("HTTP: " . $e->getMessage());
+                rcube::raise_error("HTTP: " . $e->getMessage(), true, false);
             }
         }
 
         // proxy User-Agent
         $request->setHeader('user-agent', $_SERVER['HTTP_USER_AGENT']);
 
         // some HTTP server configurations require this header
         $request->setHeader('accept', self::ACCEPT_HEADER);
 
         $request->setHeader('Content-Type', 'application/json; charset=UTF-8');
     }
 
     /**
      * Return API's base URL
      *
      * @return string Base URL
      */
     public function base_url()
     {
         return $this->base_url;
     }
 
     /**
      * Return HTTP_Request2 object
      *
      * @return HTTP_Request2 Request object
      */
     public function request()
     {
         return $this->request;
     }
 
     /**
      * Logs specified user into the API
      *
      * @param string $username User name
      * @param string $password User password
      *
      * @return string Session token (on success)
      */
     public function login($username, $password)
     {
         $query = array(
             'email'    => $username,
             'password' => $password,
         );
 
         // remove current token if any
         $this->request->setHeader('Authorization');
 
         // authenticate the user
         $response = $this->post('auth/local', $query);
 
         if ($token = $response->get('token')) {
             $this->set_session_token($token);
         }
 
         return $token;
     }
 
     /**
      * Sets request session token.
      *
      * @param string $token    Session token.
      * @param bool   $validate Enables token validatity check
      *
      * @return bool Token validity status
      */
     public function set_session_token($token, $validate = false)
     {
         $this->request->setHeader('Authorization', "Bearer $token");
 
         if ($validate) {
             $result = $this->get('api/users/me');
 
             return $result->get_error_code() == 200;
         }
 
         return true;
     }
 
     /**
      * Delete document editing session
      *
      * @param array $id Session identifier
      *
      * @return bool True on success, False on failure
      */
     public function document_delete($id)
     {
         $res = $this->delete('api/documents/' . $id);
 
         return $res->get_error_code() == 204;
     }
 
     /**
      * Create document editing session
      *
      * @param array $params Session parameters
      *
      * @return bool True on success, False on failure
      */
     public function document_create($params)
     {
         $res = $this->post('api/documents', $params);
 
         // @FIXME: 422?
         return $res->get_error_code() == 201 || $res->get_error_code() == 422;
     }
 
     /**
      * Add document editor (update 'access' array)
      *
      * @param array $session_id Session identifier
      * @param array $identity   User identifier
      *
      * @return bool True on success, False on failure
      */
     public function editor_add($session_id, $identity, $permission)
     {
         $res = $this->get("api/documents/$session_id/access");
 
         if ($res->get_error_code() != 200) {
             return false;
         }
 
         $access = $res->get();
 
         // sanity check, this should never be empty
         if (empty($access)) {
             return false;
         }
 
         // add editor to the 'access' array
         foreach ($access as $entry) {
             if ($entry['identity'] == $identity) {
                 return true;
             }
         }
 
         $access[] = array('identity' => $identity, 'permission' => $permission);
 
         $res = $this->put("api/documents/$session_id/access", $access);
 
         return $res->get_error_code() == 200;
     }
 
     /**
      * Remove document editor (update 'access' array)
      *
      * @param array $session_id Session identifier
      * @param array $identity   User identifier
      *
      * @return bool True on success, False on failure
      */
     public function editor_delete($session_id, $identity)
     {
         $res = $this->get("api/documents/$session_id/access");
 
         if ($res->get_error_code() != 200) {
             return false;
         }
 
         $access = $res->get();
         $found  = true;
 
         // remove editor from the 'access' array
         foreach ((array) $access as $idx => $entry) {
             if ($entry['identity'] == $identity) {
                 unset($access[$idx]);
             }
         }
 
         if (!$found) {
             return false;
         }
 
         $res = $this->put("api/documents/$session_id/access", $access);
 
         return $res->get_error_code() == 200;
     }
 
     /**
      * API's GET request.
      *
      * @param string $action Action name
      * @param array  $get    Request arguments
      *
      * @return file_ui_api_result Response
      */
     public function get($action, $get = array())
     {
         $url = $this->build_url($action, $get);
 
         if ($this->debug) {
             rcube::write_log('manticore', "GET: $url " . json_encode($get));
         }
 
         $this->request->setMethod(HTTP_Request2::METHOD_GET);
         $this->request->setBody('');
 
         return $this->get_response($url);
     }
 
     /**
      * API's POST request.
      *
      * @param string $action Action name
      * @param array  $post   POST arguments
      *
      * @return kolab_client_api_result Response
      */
     public function post($action, $post = array())
     {
         $url = $this->build_url($action);
 
         if ($this->debug) {
             rcube::write_log('manticore', "POST: $url " . json_encode($post));
         }
 
         $this->request->setMethod(HTTP_Request2::METHOD_POST);
         $this->request->setBody(json_encode($post));
 
         return $this->get_response($url);
     }
 
     /**
      * API's PUT request.
      *
      * @param string $action Action name
      * @param array  $post   POST arguments
      *
      * @return kolab_client_api_result Response
      */
     public function put($action, $post = array())
     {
         $url = $this->build_url($action);
 
         if ($this->debug) {
             rcube::write_log('manticore', "PUT: $url " . json_encode($post));
         }
 
         $this->request->setMethod(HTTP_Request2::METHOD_PUT);
         $this->request->setBody(json_encode($post));
 
         return $this->get_response($url);
     }
 
     /**
      * API's DELETE request.
      *
      * @param string $action Action name
      * @param array  $get    Request arguments
      *
      * @return file_ui_api_result Response
      */
     public function delete($action, $get = array())
     {
         $url = $this->build_url($action, $get);
 
         if ($this->debug) {
             rcube::write_log('manticore', "DELETE: $url " . json_encode($get));
         }
 
         $this->request->setMethod(HTTP_Request2::METHOD_DELETE);
         $this->request->setBody('');
 
         return $this->get_response($url);
     }
 
     /**
      * @param string $action Action GET parameter
      * @param array  $args   GET parameters (hash array: name => value)
      *
      * @return Net_URL2 URL object
      */
     private function build_url($action, $args = array())
     {
         $url = new Net_URL2($this->base_url . $action);
 
         $url->setQueryVariables((array) $args);
 
         return $url;
     }
 
     /**
      * HTTP Response handler.
      *
      * @param Net_URL2 $url URL object
      *
      * @return kolab_client_api_result Response object
      */
     private function get_response($url)
     {
         try {
             $this->request->setUrl($url);
             $response = $this->request->send();
         }
         catch (Exception $e) {
             return new file_ui_api_result(null,
                 self::ERROR_CONNECTION, $e->getMessage());
         }
 
         try {
             $body = $response->getBody();
         }
         catch (Exception $e) {
             return new file_ui_api_result(null,
                 self::ERROR_INTERNAL, $e->getMessage());
         }
 
         $code = $response->getStatus();
 
         if ($this->debug) {
             rcube::write_log('manticore', "Response [$code]: $body");
         }
 
         if ($code < 300) {
             $result = $body ? json_decode($body, true) : array();
         }
         else {
             if ($code != 401) {
                 rcube::raise_error("Error $code on $url", true, false);
             }
 
             $error = $body;
         }
 
         return new file_ui_api_result($result, $code, $error);
     }
 }
diff --git a/lib/file_ui_api.php b/lib/file_ui_api.php
index 542f803..b5d57e9 100644
--- a/lib/file_ui_api.php
+++ b/lib/file_ui_api.php
@@ -1,289 +1,289 @@
 <?php
 /*
  +--------------------------------------------------------------------------+
  | This file is part of the Kolab File API                                  |
  |                                                                          |
  | Copyright (C) 2011-2012, Kolab Systems AG                                |
  |                                                                          |
  | 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/>      |
  +--------------------------------------------------------------------------+
  | Author: Aleksander Machniak <machniak@kolabsys.com>                      |
  +--------------------------------------------------------------------------+
 */
 
 /**
  * Helper class to connect to the API
  */
 class file_ui_api
 {
     /**
      * @var HTTP_Request2
      */
     private $request;
 
     /**
      * @var string
      */
     private $base_url;
 
     const ERROR_INTERNAL   = 100;
     const ERROR_CONNECTION = 200;
 
     const ACCEPT_HEADER = "application/json,text/javascript,*/*";
 
     /**
      * Class constructor.
      *
      * @param string $base_url Base URL of the Kolab API
      */
     public function __construct($base_url)
     {
         $this->base_url = $base_url;
         $this->init();
     }
 
     /**
      * Initializes HTTP Request object.
      */
     public function init()
     {
         require_once 'HTTP/Request2.php';
         $this->request = new HTTP_Request2();
         self::configure($this->request);
     }
 
     /**
      * Configure HTTP_Request2 object
      *
      * @param HTTP_Request2 $request Request object
      */
     public static function configure($request)
     {
         // Configure connection options
         $config      = rcube::get_instance()->config;
         $http_config = (array) $config->get('http_request', $config->get('kolab_http_request'));
 
         // Deprecated config, all options are separated variables
         if (empty($http_config)) {
             $options = array(
                 'ssl_verify_peer',
                 'ssl_verify_host',
                 'ssl_cafile',
                 'ssl_capath',
                 'ssl_local_cert',
                 'ssl_passphrase',
                 'follow_redirects',
             );
 
             foreach ($options as $optname) {
                 if (($optvalue = $config->get($optname)) !== null
                     || ($optvalue = $config->get('kolab_' . $optname)) !== null
                 ) {
                     $http_config[$optname] = $optvalue;
                 }
             }
         }
 
         if (!empty($http_config)) {
             try {
                 $request->setConfig($http_config);
             }
             catch (Exception $e) {
-//                rcube::log_error("HTTP: " . $e->getMessage());
+                //rcube::raise_error("HTTP: " . $e->getMessage(), true, false);
             }
         }
 
         // proxy User-Agent
         $request->setHeader('user-agent', $_SERVER['HTTP_USER_AGENT']);
 
         // some HTTP server configurations require this header
         $request->setHeader('accept', self::ACCEPT_HEADER);
     }
 
     /**
      * Return API's base URL
      *
      * @return string Base URL
      */
     public function base_url()
     {
         return $this->base_url;
     }
 
     /**
      * Return HTTP_Request2 object
      *
      * @return HTTP_Request2 Request object
      */
     public function request()
     {
         return $this->request;
     }
 
     /**
      * Logs specified user into the API
      *
      * @param string $username User name
      * @param string $password User password
      * @param array  $get      Additional GET parameters (e.g. 'version')
      *
      * @return file_ui_api_result Request response
      */
     public function login($username, $password, $get = null)
     {
         $query = array(
             'username' => $username,
             'password' => $password,
         );
 
         $response = $this->post('authenticate', $get, $query);
 
         return $response;
     }
 
     /**
      * Logs specified user out of the API
      *
      * @return bool True on success, False on failure
      */
     public function logout()
     {
         $response = $this->get('quit');
 
         return $response->get_error_code() ? false : true;
     }
 
     /**
      * Sets session token value.
      *
      * @param string $token  Token string
      */
     public function set_session_token($token)
     {
         $this->request->setHeader('X-Session-Token', $token);
     }
 
     /**
      * Gets capabilities of the API (according to logged in user).
      *
      * @return kolab_client_api_result  Capabilities response
      */
     public function get_capabilities()
     {
         $this->get('capabilities');
     }
 
     /**
      * API's GET request.
      *
      * @param string $action  Action name
      * @param array  $args    Request arguments
      *
      * @return file_ui_api_result  Response
      */
     public function get($action, $args = array())
     {
         $url = $this->build_url($action, $args);
 
 //        Log::trace("Calling API GET: $url");
 
         $this->request->setMethod(HTTP_Request2::METHOD_GET);
 
         return $this->get_response($url);
     }
 
     /**
      * API's POST request.
      *
      * @param string $action    Action name
      * @param array  $url_args  URL arguments
      * @param array  $post      POST arguments
      *
      * @return kolab_client_api_result  Response
      */
     public function post($action, $url_args = array(), $post = array())
     {
         $url = $this->build_url($action, $url_args);
 
 //        Log::trace("Calling API POST: $url");
 
         $this->request->setMethod(HTTP_Request2::METHOD_POST);
         $this->request->addPostParameter($post);
 
         return $this->get_response($url);
     }
 
     /**
      * @param string $action Action GET parameter
      * @param array  $args   GET parameters (hash array: name => value)
      *
      * @return Net_URL2 URL object
      */
     private function build_url($action, $args)
     {
         $url = new Net_URL2($this->base_url);
 
         $args['method'] = $action;
 
         $url->setQueryVariables($args);
 
         return $url;
     }
 
     /**
      * HTTP Response handler.
      *
      * @param Net_URL2 $url URL object
      *
      * @return kolab_client_api_result Response object
      */
     private function get_response($url)
     {
         try {
             $this->request->setUrl($url);
             $response = $this->request->send();
         }
         catch (Exception $e) {
             return new file_ui_api_result(null,
                 self::ERROR_CONNECTION, $e->getMessage());
         }
 
         try {
             $body = $response->getBody();
         }
         catch (Exception $e) {
             return new file_ui_api_result(null,
                 self::ERROR_INTERNAL, $e->getMessage());
         }
 
         $body     = @json_decode($body, true);
         $err_code = null;
         $err_str  = null;
 
         if (is_array($body) && (empty($body['status']) || $body['status'] != 'OK')) {
             $err_code = !empty($body['code']) ? $body['code'] : self::ERROR_INTERNAL;
             $err_str  = !empty($body['reason']) ? $body['reason'] : 'Unknown error';
         }
         else if (!is_array($body)) {
             $err_code = self::ERROR_INTERNAL;
             $err_str  = 'Unable to decode response';
         }
 
         if (!$err_code && array_key_exists('result', (array) $body)) {
             $body = $body['result'];
         }
 
         return new file_ui_api_result($body, $err_code, $err_str);
     }
 }
diff --git a/lib/file_wopi.php b/lib/file_wopi.php
index 0442346..c752dc8 100644
--- a/lib/file_wopi.php
+++ b/lib/file_wopi.php
@@ -1,356 +1,356 @@
 <?php
 /**
  +--------------------------------------------------------------------------+
  | This file is part of the Kolab File API                                  |
  |                                                                          |
  | Copyright (C) 2012-2017, Kolab Systems AG                                |
  |                                                                          |
  | 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/>      |
  +--------------------------------------------------------------------------+
  | Author: Aleksander Machniak <machniak@kolabsys.com>                      |
  +--------------------------------------------------------------------------+
 */
 
 /**
  * Document editing sessions handling (WOPI)
  */
 class file_wopi extends file_document
 {
     protected $cache;
 
     // Mimetypes supported by CODE, but not advertised by all possible names
     protected $mimetype_aliases = array(
         'application/vnd.corel-draw' => 'image/x-coreldraw',
     );
 
     // Mimetypes supported by other Chwala viewers or ones we don't want to be editable
     protected $mimetype_exceptions = array(
         'text/plain',
         'image/bmp',
         'image/png',
         'image/jpeg',
         'image/jpg',
         'image/pjpeg',
         'image/gif',
         'image/tiff',
         'image/x-tiff',
     );
 
     /**
      * Return viewer URI for specified file/session. This creates
      * a new collaborative editing session when needed.
      *
      * @param string $file        File path
      * @param array  &$file_info  File metadata (e.g. type)
      * @param string &$session_id Optional session ID to join to
      * @param string $readonly    Create readonly (one-time) session
      *
      * @return string WOPI URI for specified document
      * @throws Exception
      */
     public function session_start($file, &$file_info, &$session_id = null, $readonly = false)
     {
         parent::session_start($file, $file_info, $session_id, $readonly);
 
         if ($session_id) {
             // Create Chwala session for use as WOPI access_token
             // This session will have access to this one document session only
             $keys = array('env', 'user_id', 'user', 'username', 'password',
                 'storage_host', 'storage_port', 'storage_ssl', 'user_roledns');
 
             $data = array_intersect_key($_SESSION, array_flip($keys));
             $data['document_session'] = $session_id;
 
             $this->token = $this->api->session->create($data);
 
             $this->log_login($session_id);
         }
 
         return $this->frame_uri($session_id, $file_info['type']);
     }
 
     /**
      * Generate URI of WOPI editing session (WOPIsrc)
      */
     protected function frame_uri($id, $mimetype)
     {
         $capabilities = $this->capabilities();
 
         if (empty($capabilities) || empty($mimetype)) {
             return;
         }
 
         $metadata = $capabilities[strtolower($mimetype)];
 
         if (empty($metadata)) {
             return;
         }
 
         $office_url  = rtrim($metadata['urlsrc'], ' /?'); // collabora
         $service_url = $this->api->api_url() . '/wopi/files/' . $id;
 
         // @TODO: Parsing and replacing placeholder values
         // https://wopi.readthedocs.io/en/latest/discovery.html#action-urls
 
         $args = array('WOPISrc' => $service_url);
 
         // We could also set: title, closebutton, revisionhistory
         // @TODO: do it in editor_post_params() when supported by the editor
         if ($lang = $this->api->env['language']) {
             $args['lang'] = str_replace('_', '-', $lang);
         }
 
         return $office_url . '?' . http_build_query($args, '', '&');
     }
 
     /**
      * Retern extra viewer parameters to post to the viewer iframe
      *
      * @param array $info File info
      *
      * @return array POST parameters
      */
     public function editor_post_params($info)
     {
         // Access token TTL (number of milliseconds since January 1, 1970 UTC)
         if ($ttl = $this->rc->config->get('session_lifetime', 0) * 60) {
             $now = new DateTime('now', new DateTimeZone('UTC'));
             $ttl = ($ttl + $now->format('U')) . '000';
         }
 
         $params = array(
             'access_token'     => $this->token,
             'access_token_ttl' => $ttl ?: 0,
         );
 
         return $params;
     }
 
     /**
      * List supported mimetypes
      *
      * @param bool $editable Return only editable mimetypes
      *
      * @return array List of supported mimetypes
      */
     public function supported_filetypes($editable = false)
     {
         $caps = $this->capabilities();
 
         if ($editable) {
             $editable = array();
             foreach ($caps as $mimetype => $c) {
                 if ($c['name'] == 'edit') {
                     $editable[] = $mimetype;
                 }
             }
 
             return $editable;
         }
 
         return array_keys($caps);
     }
 
     /**
      * Uses WOPI discovery to get Office capabilities
      * https://wopi.readthedocs.io/en/latest/discovery.html
      */
     protected function capabilities()
     {
         $cache_key = 'wopi.capabilities';
         if ($result = $this->get_from_cache($cache_key)) {
             return $this->apply_aliases_and_exceptions($result);
         }
 
         $office_url  = rtrim($this->rc->config->get('fileapi_wopi_office'), ' /');
         $office_url .= '/hosting/discovery';
 
         try {
             $request = $this->http_request();
             $request->setMethod(HTTP_Request2::METHOD_GET);
             $request->setBody('');
             $request->setUrl($office_url);
 
             $response = $request->send();
             $body     = $response->getBody();
             $code     = $response->getStatus();
 
             if (empty($body) || $code != 200) {
                 throw new Exception("Unexpected WOPI discovery response");
             }
         }
         catch (Exception $e) {
             rcube::raise_error($e, true, false);
 
             // Don't bail out here, it would make the kolab_files UI broken
             return array();
         }
 
         // parse XML output
         // <wopi-discovery>
         //   <net-zone name="external-http">
         //     <app name="application/vnd.lotus-wordpro">
         //       <action ext="lwp" name="edit" urlsrc="https://office.example.org/loleaflet/1.8.3/loleaflet.html?"/>
         //     </app>
         // ...
 
         $node = new DOMDocument('1.0', 'UTF-8');
         $node->loadXML($body);
 
         $result = array();
 
         foreach ($node->getElementsByTagName('app') as $app) {
             if ($mimetype = $app->getAttribute('name')) {
                 if ($action = $app->getElementsByTagName('action')->item(0)) {
                     foreach ($action->attributes as $attr) {
                         $result[$mimetype][$attr->name] = $attr->value;
                     }
                 }
             }
         }
 
         if (empty($result)) {
             rcube::raise_error("Failed to parse WOPI discovery response: $body", true, false);
 
             // Don't bail out here, it would make the kolab_files UI broken
             return array();
         }
 
         $this->save_in_cache($cache_key, $result);
 
         return $this->apply_aliases_and_exceptions($result);
     }
 
     /**
      * Initializes HTTP request object
      */
     protected function http_request()
     {
         require_once 'HTTP/Request2.php';
 
         $request = new HTTP_Request2();
 
         // Configure connection options
         $config      = $this->rc->config;
         $http_config = (array) $config->get('http_request', $config->get('kolab_http_request'));
 
         // Deprecated config, all options are separated variables
         if (empty($http_config)) {
             $options = array(
                 'ssl_verify_peer',
                 'ssl_verify_host',
                 'ssl_cafile',
                 'ssl_capath',
                 'ssl_local_cert',
                 'ssl_passphrase',
                 'follow_redirects',
             );
 
             foreach ($options as $optname) {
                 if (($optvalue = $config->get($optname)) !== null
                     || ($optvalue = $config->get('kolab_' . $optname)) !== null
                 ) {
                     $http_config[$optname] = $optvalue;
                 }
             }
         }
 
         if (!empty($http_config)) {
             try {
                 $request->setConfig($http_config);
             }
             catch (Exception $e) {
-                rcube::log_error("HTTP: " . $e->getMessage());
+                rcube::raise_error("HTTP: " . $e->getMessage(), true, false);
             }
         }
 
         // proxy User-Agent
         $request->setHeader('user-agent', $_SERVER['HTTP_USER_AGENT']);
 
         // some HTTP server configurations require this header
         $request->setHeader('accept', "application/json,text/javascript,*/*");
 
         return $request;
     }
 
     /**
      * Get cached data
      */
     protected function get_from_cache($key)
     {
         if ($cache = $this->get_cache()) {
             return $cache->get($key);
         }
     }
 
     /**
      * Store data in cache
      */
     protected function save_in_cache($key, $value)
     {
         if ($cache = $this->get_cache()) {
             $cache->set($key, $value);
         }
     }
 
     /**
      * Getter for the shared cache engine object
      */
     protected function get_cache()
     {
         if ($this->cache === null) {
             $this->cache = $this->rc->get_cache_shared('fileapi') ?: false;
         }
 
         return $this->cache;
     }
 
     /**
      * Support more mimetypes in CODE capabilities
      */
     protected function apply_aliases_and_exceptions($caps)
     {
         foreach ($this->mimetype_aliases as $type => $alias) {
             if (isset($caps[$type]) && !isset($caps[$alias])) {
                 $caps[$alias] = $caps[$type];
             }
         }
 
         foreach ($this->mimetype_exceptions as $type) {
             unset($caps[$type]);
         }
 
         return $caps;
     }
 
     /**
      * Write login data (name, ID, IP address) to the 'userlogins' log file.
      */
     protected function log_login($session_id)
     {
         if (!$this->api->config->get('log_logins')) {
             return;
         }
 
         $rcube     = rcube::get_instance();
         $user_name = $rcube->get_user_name();
         $user_id   = $rcube->get_user_id();
 
         $message = sprintf('CODE access for %s (ID: %d) from %s in session %s; %s',
             $user_name, $user_id, rcube_utils::remote_ip(), session_id(), $session_id);
 
         // log login
         rcube::write_log('userlogins', $message);
     }
 }