Plugin API: Add 'render_folder_selector' hook

CHANGELOG

@@ -9,6 +9,7 @@ CHANGELOG Roundcube Webmail
 - Support $HasAttachment/$HasNoAttachment keywords (#6201)
 - Support PECL memcached extension as a session and cache storage driver (experimental)
 - installto.sh: Add possibility to run the update even on the up-to-date installation (#6533)
+- Plugin API: Add 'render_folder_selector' hook
 - Redis: Support connection to unix socket
 - Elastic: Add Prev/Next buttons on message page toolbar (#6648)
 - Elastic: Close search options on Enter key press in quick-search input (#6660)

program/include/rcmail.php

@@ -1501,6 +1501,16 @@ class rcmail extends rcube
             $this->build_folder_tree($a_mailboxes, $folder, $delimiter);
         }
 
+        // allow plugins to alter the folder tree or to localize folder names
+        $hook = $this->plugins->exec_hook('render_folder_selector', array(
+            'list'      => $a_mailboxes,
+            'delimiter' => $delimiter,
+            'attribs'   => $p,
+        ));
+
+        $a_mailboxes = $hook['list'];
+        $p           = $hook['attribs'];
+
         $select = new html_select($p);
 
         if ($p['noselection']) {