diff --git a/program/include/rcmail_install.php b/program/include/rcmail_install.php
index 183ecff3c..23829a6f4 100644
--- a/program/include/rcmail_install.php
+++ b/program/include/rcmail_install.php
@@ -1,931 +1,934 @@
 <?php
 
 /**
  +-----------------------------------------------------------------------+
  | This file is part of the Roundcube Webmail client                     |
  |                                                                       |
  | Copyright (C) The Roundcube Dev Team                                  |
  |                                                                       |
  | Licensed under the GNU General Public License version 3 or            |
  | any later version with exceptions for skins & plugins.                |
  | See the README file for a full license statement.                     |
  |                                                                       |
  | PURPOSE:                                                              |
  |   Roundcube Installer                                                 |
  +-----------------------------------------------------------------------+
  | Author: Thomas Bruederli <roundcube@gmail.com>                        |
  | Author: Aleksander Machniak <alec@alec.pl>                            |
  +-----------------------------------------------------------------------+
 */
 
 /**
  * Class to control the installation process of the Roundcube Webmail package
  *
  * @category Install
  * @package  Webmail
  */
 class rcmail_install
 {
     public $step;
     public $last_error;
     public $is_post           = false;
     public $failures          = 0;
     public $config            = [];
     public $defaults          = [];
     public $comments          = [];
     public $configured        = false;
     public $legacy_config     = false;
     public $email_pattern     = '([a-z0-9][a-z0-9\-\.\+\_]*@[a-z0-9]([a-z0-9\-][.]?)*[a-z0-9])';
 
     public $bool_config_props = ['ip_check', 'enable_spellcheck', 'auto_create_user', 'smtp_log', 'prefer_html'];
     public $local_config    = ['db_dsnw', 'imap_host', 'support_url', 'des_key', 'plugins'];
     public $obsolete_config = ['db_backend', 'db_max_length', 'double_auth', 'preview_pane', 'debug_level', 'referer_check'];
     public $replaced_config = [
         'skin_path'            => 'skin',
         'locale_string'        => 'language',
         'multiple_identities'  => 'identities_level',
         'addrbook_show_images' => 'show_images',
         'imap_root'            => 'imap_ns_personal',
         'pagesize'             => 'mail_pagesize',
         'top_posting'          => 'reply_mode',
         'keep_alive'           => 'refresh_interval',
         'min_keep_alive'       => 'min_refresh_interval',
         'default_host'         => 'imap_host',
         'smtp_server'          => 'smtp_host',
     ];
 
     // List of configuration options supported by the Installer
     public $supported_config = [
         'product_name', 'support_url', 'temp_dir', 'des_key', 'ip_check', 'enable_spellcheck',
         'spellcheck_engine', 'identities_level', 'log_driver', 'log_dir', 'syslog_id',
         'syslog_facility', 'db_dsnw', 'db_prefix', 'imap_host', 'username_domain',
         'auto_create_user', 'sent_mbox', 'trash_mbox', 'drafts_mbox', 'junk_mbox',
         'smtp_host', 'smtp_user', 'smtp_pass', 'smtp_log', 'language', 'skin', 'mail_pagesize',
         'addressbook_pagesize', 'prefer_html', 'htmleditor', 'draft_autosave', 'mdn_requests',
         'mime_param_folding', 'plugins',
     ];
 
     // list of supported database drivers
     public $supported_dbs = [
         'MySQL'               => 'pdo_mysql',
         'PostgreSQL'          => 'pdo_pgsql',
         'SQLite'              => 'pdo_sqlite',
         'SQLite (v2)'         => 'pdo_sqlite2',
         'SQL Server (SQLSRV)' => 'pdo_sqlsrv',
         'SQL Server (DBLIB)'  => 'pdo_dblib',
         'Oracle'              => 'oci8',
     ];
 
     /** @var array List of config options with default value change per-release */
     public $defaults_changes = [
         '1.4.0' => ['skin', 'smtp_port', 'smtp_user', 'smtp_pass'],
         '1.4.1' => ['jquery_ui_skin_map'],
     ];
 
     /**
      * Constructor
      */
     public function __construct()
     {
         $this->step    = isset($_REQUEST['_step']) ? intval($_REQUEST['_step']) : 0;
         $this->is_post = isset($_SERVER['REQUEST_METHOD']) && $_SERVER['REQUEST_METHOD'] == 'POST';
     }
 
     /**
      * Singleton getter
      */
     public static function get_instance()
     {
         static $inst;
 
         if (!$inst) {
             $inst = new rcmail_install();
         }
 
         return $inst;
     }
 
     /**
      * Read the local config files and store properties
      */
     public function load_config()
     {
         if ($this->configured) {
             return;
         }
 
         // defaults
         if ($config = $this->load_config_file(RCUBE_CONFIG_DIR . 'defaults.inc.php')) {
             $this->config   = (array) $config;
             $this->defaults = $this->config;
         }
 
         $config = null;
 
         // config
         if ($config = $this->load_config_file(RCUBE_CONFIG_DIR . 'config.inc.php')) {
             $this->config = array_merge($this->config, $config);
         }
         else {
             if ($config = $this->load_config_file(RCUBE_CONFIG_DIR . 'main.inc.php')) {
                 $this->config        = array_merge($this->config, $config);
                 $this->legacy_config = true;
             }
 
             if ($config = $this->load_config_file(RCUBE_CONFIG_DIR . 'db.inc.php')) {
                 $this->config        = array_merge($this->config, $config);
                 $this->legacy_config = true;
             }
         }
 
         $this->configured = !empty($config);
     }
 
     /**
      * Read the default config file and store properties
      *
      * @param string $file File name with path
      */
     public function load_config_file($file)
     {
         if (!is_readable($file)) {
             return;
         }
 
         $config        = [];
         $rcmail_config = []; // deprecated var name
 
         include $file;
 
         // read comments from config file
         if (function_exists('token_get_all')) {
             $tokens    = token_get_all(file_get_contents($file));
             $in_config = false;
             $buffer    = '';
 
             for ($i = 0; $i < count($tokens); $i++) {
                 $token = $tokens[$i];
                 if ($token[0] == T_VARIABLE && ($token[1] == '$config' || $token[1] == '$rcmail_config')) {
                     $in_config = true;
                     if ($buffer && $tokens[$i+1] == '[' && $tokens[$i+2][0] == T_CONSTANT_ENCAPSED_STRING) {
                         $propname = trim($tokens[$i+2][1], "'\"");
                         $this->comments[$propname] = preg_replace('/\n\n/', "\n", $buffer);
                         $buffer = '';
                         $i += 3;
                     }
                 }
                 else if ($in_config && $token[0] == T_COMMENT) {
                     $buffer .= strtr($token[1], ['\n' => "\n"]) . "\n";
                 }
             }
         }
 
         return array_merge((array) $rcmail_config, (array) $config);
     }
 
     /**
      * Getter for a certain config property
      *
      * @param string $name    Property name
      * @param string $default Default value
      *
      * @return mixed The property value
      */
     public function getprop($name, $default = '')
     {
         $value = $this->config[$name] ?? null;
 
         if ($name == 'des_key' && !$this->configured && !isset($_REQUEST["_$name"])) {
             $value = rcube_utils::random_bytes(24);
         }
 
         return $value !== null && $value !== '' ? $value : $default;
     }
 
     /**
      * Create configuration file that contains parameters
      * that differ from default values.
      *
      * @param bool $use_post Use POSTed configuration values (of supported options)
      *
      * @return string The complete config file content
      */
     public function create_config($use_post = true)
     {
         $config = [];
 
         foreach ($this->config as $prop => $default) {
             $post_value = $_POST["_$prop"] ?? null;
             $value      = $default;
 
             if ($use_post && in_array($prop, $this->supported_config)
                 && ($post_value !== null || in_array($prop, $this->bool_config_props))
             ) {
                 $value = $post_value;
             }
 
             // always disable installer
             if ($prop == 'enable_installer') {
                 $value = false;
             }
 
             // generate new encryption key, never use the default value
             if ($prop == 'des_key' && $value == $this->defaults[$prop]) {
                 $value = rcube_utils::random_bytes(24);
             }
 
             // convert some form data
             if ($prop == 'db_dsnw' && !empty($_POST['_dbtype'])) {
                 if ($_POST['_dbtype'] == 'sqlite') {
                     $value = sprintf('%s://%s?mode=0646', $_POST['_dbtype'],
                         $_POST['_dbname'][0] == '/' ? '/' . $_POST['_dbname'] : $_POST['_dbname']);
                 }
                 else if ($_POST['_dbtype']) {
                     $value = sprintf('%s://%s:%s@%s/%s', $_POST['_dbtype'],
                         rawurlencode($_POST['_dbuser']), rawurlencode($_POST['_dbpass']), $_POST['_dbhost'], $_POST['_dbname']);
                 }
             }
             else if ($prop == 'imap_host' && is_array($value)) {
                 $value = self::_clean_array($value);
                 if (count($value) <= 1) {
                     $value = $value[0];
                 }
             }
             else if ($prop == 'mail_pagesize' || $prop == 'addressbook_pagesize') {
                 $value = max(2, intval($value));
             }
             else if ($prop == 'smtp_user' && !empty($_POST['_smtp_user_u'])) {
                 $value = '%u';
             }
             else if ($prop == 'smtp_pass' && !empty($_POST['_smtp_user_u'])) {
                 $value = '%p';
             }
             else if (is_bool($default)) {
                 $value = (bool) $value;
             }
             else if (is_numeric($value)) {
                 $value = intval($value);
             }
             else if ($prop == 'plugins' && !empty($_POST['submit'])) {
                 $value = [];
                 foreach (array_keys($_POST) as $key) {
                     if (preg_match('/^_plugins_*/', $key)) {
                         array_push($value, $_POST[$key]);
                     }
                 }
             }
 
             // skip this property
             if ($value == ($this->defaults[$prop] ?? null)
                 && (!in_array($prop, $this->local_config)
                     || in_array($prop, array_merge($this->obsolete_config, array_keys($this->replaced_config)))
                     || preg_match('/^db_(table|sequence)_/', $prop)
                 )
             ) {
                 continue;
             }
 
             // save change
             $this->config[$prop] = $value;
             $config[$prop]       = $value;
         }
 
         $out = "<?php\n\n";
         $out .= "/* Local configuration for Roundcube Webmail */\n\n";
 
         foreach ($config as $prop => $value) {
             // copy option descriptions from existing config or defaults.inc.php
             $out .= $this->comments[$prop] ?? '';
             $out .= "\$config['$prop'] = " . self::_dump_var($value, $prop) . ";\n\n";
         }
 
         return $out;
     }
 
     /**
      * save generated config file in RCUBE_CONFIG_DIR
      *
      * @return bool True if the file was saved successfully, false if not
      */
     public function save_configfile($config)
     {
         if (is_writable(RCUBE_CONFIG_DIR)) {
             return file_put_contents(RCUBE_CONFIG_DIR . 'config.inc.php', $config);
         }
 
         return false;
     }
 
     /**
      * Check the current configuration for missing properties
      * and deprecated or obsolete settings
      *
      * @param string $version Previous version on upgrade
      *
      * @return array List with problems detected
      */
     public function check_config($version = null)
     {
         $this->load_config();
 
         if (!$this->configured) {
             return;
         }
 
         $seen = [];
         $out = ['defaults' => [], 'obsolete' => [], 'replaced' => [], 'dependencies' => [], 'missing' => []];
 
         // iterate over the current configuration
         foreach (array_keys($this->config) as $prop) {
             if (!empty($this->replaced_config[$prop])) {
                 $replacement = $this->replaced_config[$prop];
                 $out['replaced'][]  = ['prop' => $prop, 'replacement' => $replacement];
                 $seen[$replacement] = true;
             }
             else if (empty($seen[$prop]) && in_array($prop, $this->obsolete_config)) {
                 $out['obsolete'][] = ['prop' => $prop];
                 $seen[$prop]       = true;
             }
         }
 
         // the old default mime_magic reference is obsolete
-        if ($this->config['mime_magic'] == '/usr/share/misc/magic') {
+        if (isset($this->config['mime_magic']) && $this->config['mime_magic'] == '/usr/share/misc/magic') {
             $out['obsolete'][] = [
                 'prop'    => 'mime_magic',
                 'explain' => "Set value to null in order to use system default"
             ];
         }
 
         // check config dependencies and contradictions
         if (!empty($this->config['enable_spellcheck']) && $this->config['spellcheck_engine'] == 'pspell') {
             if (!extension_loaded('pspell')) {
                 $out['dependencies'][] = [
                     'prop'    => 'spellcheck_engine',
                     'explain' => "This requires the <tt>pspell</tt> extension which could not be loaded."
                 ];
             }
             else if (!empty($this->config['spellcheck_languages'])) {
                 foreach ($this->config['spellcheck_languages'] as $lang => $descr) {
                     if (!@pspell_new($lang)) {
                         $out['dependencies'][] = [
                             'prop'    => 'spellcheck_languages',
                             'explain' => "You are missing pspell support for language $lang ($descr)"
                         ];
                     }
                 }
             }
         }
 
-        if ($this->config['log_driver'] == 'syslog') {
+        if (isset($this->config['log_driver']) && $this->config['log_driver'] == 'syslog') {
             if (!function_exists('openlog')) {
                 $out['dependencies'][] = [
                     'prop'    => 'log_driver',
                     'explain' => "This requires the <tt>syslog</tt> extension which could not be loaded."
                 ];
             }
 
             if (empty($this->config['syslog_id'])) {
                 $out['dependencies'][] = [
                     'prop'    => 'syslog_id',
                     'explain' => "Using <tt>syslog</tt> for logging requires a syslog ID to be configured"
                 ];
             }
         }
 
         // check ldap_public sources having global_search enabled
-        if (is_array($this->config['ldap_public']) && !is_array($this->config['autocomplete_addressbooks'])) {
+        if (!empty($this->config['ldap_public'])
+            && is_array($this->config['ldap_public'])
+            && !is_array($this->config['autocomplete_addressbooks'])
+        ) {
             foreach ($this->config['ldap_public'] as $ldap_public) {
                 if ($ldap_public['global_search']) {
                     $out['replaced'][] = [
                         'prop'        => 'ldap_public::global_search',
                         'replacement' => 'autocomplete_addressbooks'
                     ];
                     break;
                 }
             }
         }
 
         if ($version) {
             foreach ($this->defaults_changes as $v => $opts) {
                 if (version_compare($v, $version, '>')) {
                     $out['defaults'] = array_merge($out['defaults'], $opts);
                 }
             }
 
             $out['defaults'] = array_unique($out['defaults']);
         }
 
         return $out;
     }
 
     /**
      * Merge the current configuration with the defaults
      * and copy replaced values to the new options.
      */
     public function merge_config()
     {
         $current      = $this->config;
         $this->config = [];
 
         foreach ($this->replaced_config as $prop => $replacement) {
             if (isset($current[$prop])) {
                 if ($prop == 'skin_path') {
                     $this->config[$replacement] = preg_replace('#skins/(\w+)/?$#', '\\1', $current[$prop]);
                 }
                 else if ($prop == 'multiple_identities') {
                     $this->config[$replacement] = $current[$prop] ? 2 : 0;
                 }
                 else {
                     $this->config[$replacement] = $current[$prop];
                 }
 
                 unset($current[$prop]);
                 unset($current[$replacement]);
             }
         }
 
         // Merge old *_port options into the new *_host options, where possible
         foreach (['default' => 'imap', 'smtp' => 'smtp'] as $prop => $type) {
             $old_prop = "{$prop}_port";
             $new_prop = "{$type}_host";
             if (!empty($current[$old_prop]) && !empty($this->config[$new_prop])
                 && is_string($this->config[$new_prop])
                 && !preg_match('/:[0-9]+$/', $this->config[$new_prop])
             ) {
                 $this->config[$new_prop] .= ':' . $current[$old_prop];
             }
 
             unset($current[$old_prop]);
         }
 
         foreach ($this->obsolete_config as $prop) {
             unset($current[$prop]);
         }
 
         // add all ldap_public sources having global_search enabled to autocomplete_addressbooks
         if (!empty($current['ldap_public']) && is_array($current['ldap_public'])) {
             foreach ($current['ldap_public'] as $key => $ldap_public) {
                 if (!empty($ldap_public['global_search'])) {
                     $this->config['autocomplete_addressbooks'][] = $key;
                     unset($current['ldap_public'][$key]['global_search']);
                 }
             }
         }
 
         $this->config = array_merge($this->config, $current);
     }
 
     /**
      * Compare the local database schema with the reference schema
      * required for this version of Roundcube
      *
      * @param rcube_db $db Database object
      *
      * @return bool True if the schema is up-to-date, false if not or an error occurred
      */
     public function db_schema_check($db)
     {
         if (!$this->configured) {
             return false;
         }
 
         // read reference schema from mysql.initial.sql
         $engine    = $db->db_provider;
         $db_schema = $this->db_read_schema(INSTALL_PATH . "SQL/$engine.initial.sql", $schema_version);
         $errors    = [];
 
         // Just check the version
         if ($schema_version) {
             $version = rcmail_utils::db_version();
 
             if (empty($version)) {
                 $errors[] = "Schema version not found";
             }
             else if ($schema_version != $version) {
                 $errors[] = "Schema version: {$version} (required: {$schema_version})";
             }
 
             return !empty($errors) ? $errors : false;
         }
 
         // check list of tables
         $existing_tables = $db->list_tables();
 
         foreach ($db_schema as $table => $cols) {
             $table = $this->config['db_prefix'] . $table;
 
             if (!in_array($table, $existing_tables)) {
                 $errors[] = "Missing table '".$table."'";
             }
             else {  // compare cols
                 $db_cols = $db->list_cols($table);
                 $diff    = array_diff(array_keys($cols), $db_cols);
 
                 if (!empty($diff)) {
                     $errors[] = "Missing columns in table '$table': " . implode(',', $diff);
                 }
             }
         }
 
         return !empty($errors) ? $errors : false;
     }
 
     /**
      * Utility function to read database schema from an .sql file
      */
     private function db_read_schema($schemafile, &$version = null)
     {
         $lines      = file($schemafile);
         $schema     = [];
         $keywords   = ['PRIMARY','KEY','INDEX','UNIQUE','CONSTRAINT','REFERENCES','FOREIGN'];
         $table_name = null;
 
         foreach ($lines as $line) {
             if (preg_match('/^\s*create table ([\S]+)/i', $line, $m)) {
                 $table_name = explode('.', $m[1]);
                 $table_name = end($table_name);
                 $table_name = preg_replace('/[`"\[\]]/', '', $table_name);
             }
             else if (preg_match('/insert into/i', $line) && preg_match('/\'roundcube-version\',\s*\'([0-9]+)\'/', $line, $m)) {
                 $version = $m[1];
             }
             else if ($table_name && ($line = trim($line))) {
                 if ($line == 'GO' || $line[0] == ')' || $line[strlen($line)-1] == ';') {
                     $table_name = null;
                 }
                 else {
                     $items = explode(' ', $line);
                     $col   = $items[0];
                     $col   = preg_replace('/[`"\[\]]/', '', $col);
 
                     if (!in_array(strtoupper($col), $keywords)) {
                         $type = strtolower($items[1]);
                         $type = preg_replace('/[^a-zA-Z0-9()]/', '', $type);
 
                         $schema[$table_name][$col] = $type;
                     }
                 }
             }
         }
 
         return $schema;
     }
 
     /**
      * Try to detect some file's mimetypes to test the correct behavior of fileinfo
      */
     public function check_mime_detection()
     {
         $errors = [];
         $files  = [
             'program/resources/tinymce/video.png' => 'image/png',
             'program/resources/blank.tiff'        => 'image/tiff',
             'program/resources/blocked.gif'       => 'image/gif',
         ];
 
         foreach ($files as $path => $expected) {
             $mimetype = rcube_mime::file_content_type(INSTALL_PATH . $path, basename($path));
             if ($mimetype != $expected) {
                 $errors[] = [$path, $mimetype, $expected];
             }
         }
 
         return $errors;
     }
 
     /**
      * Check the correct configuration of the 'mime_types' mapping option
      */
     public function check_mime_extensions()
     {
         $errors = [];
         $types  = [
             'application/zip'   => 'zip',
             'text/css'          => 'css',
             'application/pdf'   => 'pdf',
             'image/gif'         => 'gif',
             'image/svg+xml'     => 'svg',
         ];
 
         foreach ($types as $mimetype => $expected) {
             $ext = rcube_mime::get_mime_extensions($mimetype);
             if (!in_array($expected, (array) $ext)) {
                 $errors[] = [$mimetype, $ext, $expected];
             }
         }
 
         return $errors;
     }
 
     /**
      * Getter for the last error message
      *
      * @return string Error message or null if none exists
      */
     public function get_error()
     {
         return $this->last_error['message'] ?? null;
     }
 
     /**
      * Return a list with all imap/smtp hosts configured
      *
      * @return array Clean list with imap/smtp hosts
      */
     public function get_hostlist($prop = 'imap_host')
     {
         $hosts     = (array) $this->getprop($prop);
         $out       = [];
         $imap_host = '';
 
         if ($prop == 'smtp_host') {
             // Set the imap host name for the %h macro
             $default_hosts = $this->get_hostlist();
             $imap_host = !empty($default_hosts) ? $default_hosts[0] : '';
         }
 
         foreach ($hosts as $key => $name) {
             if (!empty($name)) {
                 if ($prop == 'smtp_host') {
                     // SMTP host array uses `IMAP host => SMTP host` format
                     $host = $name;
                 }
                 else {
                     $host = is_numeric($key) ? $name : $key;
                 }
 
                 $out[] = rcube_utils::parse_host($host, $imap_host);
             }
         }
 
         return $out;
     }
 
     /**
      * Create a HTML dropdown to select a previous version of Roundcube
      */
     public function versions_select($attrib = [])
     {
         $select = new html_select($attrib);
         $select->add([
                 '0.1-stable', '0.1.1',
                 '0.2-alpha', '0.2-beta', '0.2-stable',
                 '0.3-stable', '0.3.1',
                 '0.4-beta', '0.4.2',
                 '0.5-beta', '0.5', '0.5.1', '0.5.2', '0.5.3', '0.5.4',
                 '0.6-beta', '0.6',
                 '0.7-beta', '0.7', '0.7.1', '0.7.2', '0.7.3', '0.7.4',
                 '0.8-beta', '0.8-rc', '0.8.0', '0.8.1', '0.8.2', '0.8.3', '0.8.4', '0.8.5', '0.8.6',
                 '0.9-beta', '0.9-rc', '0.9-rc2',
                 // Note: Do not add newer versions here
         ]);
 
         return $select;
     }
 
     /**
      * Return a list with available subfolders of the skin directory
      *
      * @return array List of available skins
      */
     public function list_skins()
     {
         $skins   = [];
         $skindir = INSTALL_PATH . 'skins/';
 
         foreach (glob($skindir . '*') as $path) {
             if (is_dir($path) && is_readable($path)) {
                 $skins[] = substr($path, strlen($skindir));
             }
         }
 
         return $skins;
     }
 
     /**
      * Return a list with available subfolders of the plugins directory
      * (with their associated description in composer.json)
      *
      * @return array List of available plugins
      */
     public function list_plugins()
     {
         $plugins    = [];
         $plugin_dir = INSTALL_PATH . 'plugins/';
         $enabled    = isset($this->config['plugins']) ? (array) $this->config['plugins'] : [];
 
         foreach (glob($plugin_dir . '*') as $path) {
             if (!is_dir($path)) {
                 continue;
             }
 
             if (is_readable($path . '/composer.json')) {
                 $file_json   = json_decode(file_get_contents($path . '/composer.json'));
                 $plugin_desc = $file_json->description ?: 'N/A';
             }
             else {
                 $plugin_desc = 'N/A';
             }
 
             $name      = substr($path, strlen($plugin_dir));
             $plugins[] = [
                 'name'    => $name,
                 'desc'    => $plugin_desc,
                 'enabled' => in_array($name, $enabled)
             ];
         }
 
         return $plugins;
     }
 
     /**
      * Display OK status
      *
      * @param string $name    Test name
      * @param string $message Confirm message
      */
     public function pass($name, $message = '')
     {
         echo rcube::Q($name) . ':&nbsp; <span class="success">OK</span>';
         $this->_showhint($message);
     }
 
     /**
      * Display an error status and increase failure count
      *
      * @param string $name     Test name
      * @param string $message  Error message
      * @param string $url      URL for details
      * @param bool   $optional Do not count this failure
      */
     public function fail($name, $message = '', $url = '', $optional = false)
     {
         if (!$optional) {
             $this->failures++;
         }
 
         echo rcube::Q($name) . ':&nbsp; <span class="fail">NOT OK</span>';
         $this->_showhint($message, $url);
     }
 
     /**
      * Display an error status for optional settings/features
      *
      * @param string $name    Test name
      * @param string $message Error message
      * @param string $url     URL for details
      */
     public function optfail($name, $message = '', $url = '')
     {
         echo rcube::Q($name) . ':&nbsp; <span class="na">NOT OK</span>';
         $this->_showhint($message, $url);
     }
 
     /**
      * Display warning status
      *
      * @param string $name    Test name
      * @param string $message Warning message
      * @param string $url     URL for details
      */
     public function na($name, $message = '', $url = '')
     {
         echo rcube::Q($name) . ':&nbsp; <span class="na">NOT AVAILABLE</span>';
         $this->_showhint($message, $url);
     }
 
     private function _showhint($message, $url = '')
     {
         $hint = rcube::Q($message);
 
         if ($url) {
             $hint .= ($hint ? '; ' : '') . 'See <a href="' . rcube::Q($url) . '" target="_blank">' . rcube::Q($url) . '</a>';
         }
 
         if ($hint) {
             echo '<span class="indent">(' . $hint . ')</span>';
         }
     }
 
     private static function _clean_array($arr)
     {
         $out = [];
 
         foreach (array_unique($arr) as $k => $val) {
             if (!empty($val)) {
                 if (is_numeric($k)) {
                     $out[] = $val;
                 }
                 else {
                     $out[$k] = $val;
                 }
             }
         }
 
         return $out;
     }
 
     private static function _dump_var($var, $name = null)
     {
         // special values
         switch ($name) {
         case 'syslog_facility':
             $list = [
                 32 => 'LOG_AUTH', 80 => 'LOG_AUTHPRIV', 72 => ' LOG_CRON',
                 24 => 'LOG_DAEMON', 0 => 'LOG_KERN', 128 => 'LOG_LOCAL0',
                 136 => 'LOG_LOCAL1', 144 => 'LOG_LOCAL2', 152 => 'LOG_LOCAL3',
                 160 => 'LOG_LOCAL4', 168 => 'LOG_LOCAL5', 176 => 'LOG_LOCAL6',
                 184 => 'LOG_LOCAL7', 48 => 'LOG_LPR', 16 => 'LOG_MAIL',
                 56 => 'LOG_NEWS', 40 => 'LOG_SYSLOG', 8 => 'LOG_USER', 64 => 'LOG_UUCP'
             ];
 
             if (!empty($list[$var])) {
                 return $list[$var];
             }
 
             break;
         }
 
         if (is_array($var)) {
             if (empty($var)) {
                 return '[]';
             }
             // check if all keys are numeric
             $isnum = true;
             foreach (array_keys($var) as $key) {
                 if (!is_numeric($key)) {
                     $isnum = false;
                     break;
                 }
             }
 
             if ($isnum) {
                 return '[' . implode(', ', array_map(['rcmail_install', '_dump_var'], $var)) . ']';
             }
         }
 
         return var_export($var, true);
     }
 
     /**
      * Initialize the database with the according schema
      *
      * @param rcube_db $db Database connection
      *
      * @return bool True on success, False on error
      */
     public function init_db($db)
     {
         $engine = $db->db_provider;
 
         // read schema file from /SQL/*
         $fname = INSTALL_PATH . "SQL/$engine.initial.sql";
         if ($sql = @file_get_contents($fname)) {
             $db->set_option('table_prefix', $this->config['db_prefix']);
             $db->exec_script($sql);
         }
         else {
             $this->fail('DB Schema', "Cannot read the schema file: $fname");
             return false;
         }
 
         if ($err = $this->get_error()) {
             $this->fail('DB Schema', "Error creating database schema: $err");
             return false;
         }
 
         return true;
     }
 
     /**
      * Update database schema
      *
      * @param string $version Version to update from
      *
      * @return boolean True on success, False on error
      */
     public function update_db($version)
     {
         return rcmail_utils::db_update(INSTALL_PATH . 'SQL', 'roundcube', $version, ['quiet' => true]);
     }
 
     /**
      * Handler for Roundcube errors
      */
     public function raise_error($p)
     {
         $this->last_error = $p;
     }
 
     /**
      * Check if vendor/autoload.php was created by Roundcube and left untouched
      *
      * @param string $target_dir The target installation dir
      * @return string
      */
     public static function vendor_dir_untouched($target_dir)
     {
         system('grep -q "generated by Roundcube" ' . escapeshellarg($target_dir . '/vendor/autoload.php') . ' 2>/dev/null', $exit_code);
         return $exit_code === 0;
     }
 }