Steps to reproduce the issue

Checking the Joomla\Input\Input class, the constructor is defined in this way:

	public function __construct($source = null, array $options = [])
	{
		$this->data    = empty($source) ? $_REQUEST : $source;
		$this->filter  = $options['filter'] ?? new Filter\InputFilter;
		$this->options = $options;
	}

As a consequence, a call to new Input([]) generates an Input initialized with the $_REQUEST, instead of generating an Input initialized with [].

According to the doc:

@param   array  $source   Optional source data. If omitted, a copy of the server variable '_REQUEST' is used.

Since the parameter $source is not committed, and it has the value [], the object should be initialized with [].

Expected result

new Input([]) initialized with []

Actual result

new Input([]) generates an object initialized with a different source.

System information (as much as possible)

Joomla 4.

Additional comments

As a workaround, to create an empty Input, the developer could call a new Input(['no-input' => 'fake-input'])...