Fix folders list sorting on Windows - if php-intl is available (#5732)

CHANGELOG

@@ -7,6 +7,7 @@ CHANGELOG Roundcube Webmail
 - Print error from CLI scripts when system/exec function is disabled (#5744)
 - Fix bug where comment notation within style tag would cause the whole style to be ignored (#5747)
 - Fix bug where it wasn't possible to scroll folders list in Edge (#5750)
+- Fix folders list sorting on Windows - if php-intl is available (#5732)
 
 RELEASE 1.3-rc
 --------------

program/lib/Roundcube/rcube.php

@@ -390,6 +390,7 @@ class rcube
         );
 
         if (!empty($_SESSION['storage_host'])) {
+            $options['language'] = $_SESSION['language'];
             $options['host']     = $_SESSION['storage_host'];
             $options['user']     = $_SESSION['username'];
             $options['port']     = $_SESSION['storage_port'];

program/lib/Roundcube/rcube_imap.php

@@ -4262,6 +4262,17 @@ class rcube_imap extends rcube_storage
      */
     protected function sort_folder_comparator($str1, $str2)
     {
+        if ($this->sort_folder_collator === null) {
+            $this->sort_folder_collator = false;
+
+            // strcoll() does not work with UTF8 locale on Windows,
+            // use Collator from the intl extension
+            if (stripos(PHP_OS, 'win') === 0 && function_exists('collator_compare')) {
+                $locale = $this->options['language'] ?: 'en_US';
+                $this->sort_folder_collator = collator_create($locale) ?: false;
+            }
+        }
+
         $path1 = explode($this->delimiter, $str1);
         $path2 = explode($this->delimiter, $str2);
 
@@ -4272,6 +4283,10 @@ class rcube_imap extends rcube_storage
                 continue;
             }
 
+            if ($this->sort_folder_collator) {
+                return collator_compare($this->sort_folder_collator, $folder1, $folder2);
+            }
+
             return strcoll($folder1, $folder2);
         }
     }

program/lib/Roundcube/rcube_storage.php

@@ -42,13 +42,13 @@ abstract class rcube_storage
      */
     public static $folder_types = array('drafts', 'sent', 'junk', 'trash');
 
-    protected $folder = 'INBOX';
+    protected $folder          = 'INBOX';
     protected $default_charset = 'ISO-8859-1';
+    protected $options         = array('auth_type' => 'check', 'language' => 'en_US');
+    protected $page_size       = 10;
+    protected $list_page       = 1;
+    protected $threading       = false;
     protected $search_set;
-    protected $options = array('auth_type' => 'check');
-    protected $page_size = 10;
-    protected $list_page = 1;
-    protected $threading = false;
 
     /**
      * All (additional) headers used (in any way) by Roundcube