Fix php warnings; Courier doesn't like spaces appended to the EXPUNGE command

1 files changed, 1 insertions, 1 deletions

diff --git a/program/include/rcube_imap.php b/program/include/rcube_imap.php
index 4c021802c..3fa24939c 100644
--- a/program/include/rcube_imap.php
+++ b/program/include/rcube_imap.php
@@ -3236,7 +3236,7 @@ class rcube_imap
             if (is_array($this->namespace['shared'])) {
                 foreach ($this->namespace['shared'] as $ns) {
                     foreach ((array)$ns as $root) {
-                        if (strpos($mbox_name, $root[0]) === 0) {
+                        if ($root[0] && strpos($mbox_name, $root[0]) === 0) {
                             return $mbox_name;
                         }
                     }