Fix regression where IMAP commands with '*' uidset argument wasn't working

CHANGELOG

@@ -1,6 +1,8 @@
 CHANGELOG Roundcube Webmail
 ===========================
 
+- Fix regression where IMAP commands with '*' uidset argument wasn't working
+
 RELEASE 1.2.8
 -------------
 - Fix check_request() bypass in places using get_uids() [CVE-2018-9846] (#6238)

program/lib/Roundcube/rcube_imap_generic.php

@@ -3879,7 +3879,7 @@ class rcube_imap_generic
         // return as comma separated string
         $result = implode(',', $result);
 
-        return preg_match('/[^0-9:,]/', $result) ? 'INVALID' : $result;
+        return preg_match('/[^0-9:,*]/', $result) ? 'INVALID' : $result;
     }
 
     /**