Fix deleting/moving folders from folders with name "0", "00", etc.

program/include/rcmail.php

@@ -2050,7 +2050,7 @@ class rcmail extends rcube
             // create a per-folder UIDs array
             foreach ((array)$_uid as $uid) {
                 list($uid, $mbox) = explode('-', $uid, 2);
-                if (empty($mbox))
+                if (!strlen($mbox))
                     $mbox = $_mbox;
                 if ($uid == '*')
                     $result[$mbox] = $uid;

program/steps/mail/copy.inc

@@ -29,7 +29,7 @@ if (!empty($_POST['_uid']) && strlen($_POST['_target_mbox'])) {
     $target = rcube_utils::get_input_value('_target_mbox', rcube_utils::INPUT_POST, true);
 
     foreach (rcmail::get_uids() as $mbox => $uids) {
-        if ($mbox == $target)
+        if ($mbox === $target)
             $copied++;
         else
             $copied += (int)$RCMAIL->storage->copy_message($uids, $target, $mbox);

program/steps/mail/move_del.inc

@@ -37,7 +37,7 @@ if ($RCMAIL->action == 'move' && !empty($_POST['_uid']) && strlen($_POST['_targe
 
     $success = true;
     foreach (rcmail::get_uids() as $mbox => $uids) {
-        if ($mbox == $target) {
+        if ($mbox === $target) {
             $count += count($uids);
         }
         else if ($RCMAIL->storage->move_message($uids, $target, $mbox)) {