Issue: https://github.com/php/php-src/issues/11952
Author: nielsdos
### Description
The following code:
```php
<?php
libxml_set_external_entity_loader(function ($public_id, $system_id, $context) {
return null;
});
$doc = new DOMDocument;
$doc->loadHTMLFile("foobar");
```
Resulted in this output:
```
Warning: DOMDocument::loadHTMLFile(): Failed to load external entity "NULL" in %s on line
%d
```
But I expected something less confusing. Now it sounds like it tries to load a file named
"NULL" but that is not the case. It just complains in a weird way.
Low priority issue though.
### PHP Version
8.1+
### Operating System
_No response_