FTP Library and PHP 8.1

[mithra62]

In PHP 8.1, the ftp_connect function was changed to return an instance of FTP\Connection instead of the previous "resource" other versions returned. Within the FTP library though, it only checks for a resource. You can read more on that here:
https://www.php.net/manual/en/function.ftp-connect

And to verify the issue, here (in 6.x):

ExpressionEngine/system/ee/legacy/libraries/Ftp.php

Line 113 in e017f71

if (! is_resource($this->conn_id)) {

And here (in 7.x):

ExpressionEngine/system/ee/legacy/libraries/Ftp.php

Line 113 in 7b4428a

if (! is_resource($this->conn_id)) {

A simple conditional should suffice, I imagine.