I'm upgrading my custom site from MediaWiki 1.25 to 1.33 and now in my custom skin if I call
$parser->setHook( 'img', 'MyClass::ImgRender' );
it still works for img tags that have a closing slash: <img src="...png"/>
But the hook is no longer called for <img src="...png"> without a closing slash.
In MediaWiki 1.25 it worked for both.