While calling QFtp::List() command to get the remote file size, it is not emitting the listinfo signal

We are using QT 4.8.1 version for developing our application. We are having a FTPSize() function for reading the remote file size. While calling this function, its always showing -1 as the file size.

In the deeper analysis, we have identified that qftp::list() command is not emitting listinfo() signal to execute the slot. Given directory contains directories and files and still its not emitting any listinfo signal.

We need you help to solve this issue.