Fix "Illegal offset type" error (#1489985)

program/lib/Roundcube/rcube_imap.php

@@ -3298,12 +3298,14 @@ class rcube_imap extends rcube_storage
         // request \Subscribed flag in LIST response as performance improvement for folder_exists()
         $folders = $this->conn->listMailboxes('', '*', array('SUBSCRIBED'), array('SPECIAL-USE'));
 
-        foreach ($folders as $folder) {
-            if ($flags = $this->conn->data['LIST'][$folder]) {
-                foreach ($types as $type) {
-                    if (in_array($type, $flags)) {
-                        $type           = strtolower(substr($type, 1));
-                        $special[$type] = $folder;
+        if (!empty($folders)) {
+            foreach ($folders as $folder) {
+                if ($flags = $this->conn->data['LIST'][$folder]) {
+                    foreach ($types as $type) {
+                        if (in_array($type, $flags)) {
+                            $type           = strtolower(substr($type, 1));
+                            $special[$type] = $folder;
+                        }
                     }
                 }
             }

program/lib/Roundcube/rcube_imap_generic.php

@@ -1296,8 +1296,8 @@ class rcube_imap_generic
      * @param array  $return_opts (see self::_listMailboxes)
      * @param array  $select_opts (see self::_listMailboxes)
      *
-     * @return array List of mailboxes or hash of options if $return_opts argument
-     *               is non-empty.
+     * @return array|bool List of mailboxes or hash of options if STATUS/MYROGHTS response
+     *                    is requested, False on error.
      */
     function listMailboxes($ref, $mailbox, $return_opts=array(), $select_opts=array())
     {
@@ -1311,8 +1311,8 @@ class rcube_imap_generic
      * @param string $mailbox     Mailbox name
      * @param array  $return_opts (see self::_listMailboxes)
      *
-     * @return array List of mailboxes or hash of options if $return_opts argument
-     *               is non-empty.
+     * @return array|bool List of mailboxes or hash of options if STATUS/MYROGHTS response
+     *                    is requested, False on error.
      */
     function listSubscribed($ref, $mailbox, $return_opts=array())
     {
@@ -1332,8 +1332,8 @@ class rcube_imap_generic
      *                            Possible: SUBSCRIBED, RECURSIVEMATCH, REMOTE,
      *                                      SPECIAL-USE (RFC6154)
      *
-     * @return array List of mailboxes or hash of options if $status_ops argument
-     *               is non-empty.
+     * @return array|bool List of mailboxes or hash of options if STATUS/MYROGHTS response
+     *                    is requested, False on error.
      */
     protected function _listMailboxes($ref, $mailbox, $subscribed=false,
         $return_opts=array(), $select_opts=array())
@@ -1355,7 +1355,9 @@ class rcube_imap_generic
         $args[] = $this->escape($mailbox);
 
         if (!empty($return_opts) && $this->getCapability('LIST-EXTENDED')) {
-            $rets = array_intersect($return_opts, array('SUBSCRIBED', 'CHILDREN'));
+            $ext_opts    = array('SUBSCRIBED', 'CHILDREN');
+            $rets        = array_intersect($return_opts, $ext_opts);
+            $return_opts = array_diff($return_opts, $rets);
         }
 
         if (!empty($return_opts) && $this->getCapability('LIST-STATUS')) {