Fix bug where a special folder couldn't be created if a special-use flag is not supported (#7147)

CHANGELOG

@@ -35,6 +35,7 @@ CHANGELOG Roundcube Webmail
 - Markasjunk: Fix bug where moving to Junk was failing on messages selected with Select > All (#7206)
 - Fix bug where session was destoryed with window close (#7251)
 - Fix so imap error message is displayed to the user on folder create/update (#7245)
+- Fix bug where a special folder couldn't be created if a special-use flag is not supported (#7147)
 
 RELEASE 1.4.3
 -------------

program/lib/Roundcube/rcube_imap.php

@@ -3261,6 +3261,12 @@ class rcube_imap extends rcube_storage
 
         $result = $this->conn->createFolder($folder, $type ? array("\\" . ucfirst($type)) : null);
 
+        // Folder creation may fail when specific special-use flag is not supported.
+        // Try to create it anyway with no flag specified (#7147)
+        if (!$result && $type) {
+            $result = $this->conn->createFolder($folder);
+        }
+
         // try to subscribe it
         if ($result) {
             // clear cache