[XML-RPC library] Object of class XMLParser could not be converted to string (PHP 8)

[luizzz]

CodeIgniter 3.1.13
PHP 8.1.10
File: /system/libraries/Xmlrpc.php

Error:
Exception: Object of class XMLParser could not be converted to string (Xmlrpc.php on line 1284)

Where:
Triggers when i call "http://localhost/api/helloWorld" (same sample as shown on documentation)
This code works flawlessly on PHP 7.4 or older.
`class Api extends CI_Controller {

function __construct()
{
    parent::__construct();
    $this->load->library('xmlrpc');
    $this->load->config('xmlrpc');
    $this->xmlrpc->debug = $this->config->item('xmlrpc_debug');
    $server_url = site_url('webservice');
    $this->xmlrpc->server($server_url, 80);
}

function helloWorld()
{
    $this->xmlrpc->method('helloWorld');
    $request = array();
    return $this->makeRequest($request);
}

}`

How i fixed it:
Target file: /system/libraries/Xmlrpc.php
Change all lines from:

$the_parser = (string) $the_parser;

To:

if(empty((array) $the_parser)) { $the_parser = '0'; } else { $the_parser = (string) $the_parser; }

Not sure if this are correct but it's works here...

[gxgpet]

No, a better approach is needed here...

Please follow up on #6186.