CS fixes and consistence, update changelog

CHANGELOG

@@ -1,6 +1,7 @@
 CHANGELOG Roundcube Webmail
 ===========================
 
+- Add skins_allowed option (#6483)
 - SMTP GSSAPI support via krb_authentication plugin (#6417)
 - Avoid Referer leaking by using Referrer-Policy:same-origin header (#6385)
 - Removed referer_check option (#6440)

config/defaults.inc.php

@@ -1057,7 +1057,7 @@ $config['default_charset'] = 'ISO-8859-1';
 $config['skin'] = 'larry';
 
 // limit skins available/shown in the settings section
-$config['skins_allowed'] = [];
+$config['skins_allowed'] = array();
 
 // Enables using standard browser windows (that can be handled as tabs)
 // instead of popup windows

program/steps/settings/func.inc

@@ -1306,16 +1306,15 @@ function rcmail_get_skins()
     $path  = RCUBE_INSTALL_PATH . 'skins';
     $skins = array();
     $dir   = opendir($path);
-    $limit = $RCMAIL->config->get('skins_allowed');
+    $limit = (array) $RCMAIL->config->get('skins_allowed');
 
     if (!$dir) {
         return false;
     }
 
     while (($file = readdir($dir)) !== false) {
-        $filename = $path.'/'.$file;
-        if (!preg_match('/^\./', $file) && is_dir($filename) && is_readable($filename)
-            && (!is_array($limit) || !count($limit) || in_array($file, $limit))) {
+        $filename = $path . '/' . $file;
+        if ($file[0] != '.' && (empty($limit) || in_array($file, $limit) && is_dir($filename) && is_readable($filename))) {
             $skins[] = $file;
         }
     }