Called get_entities() on null and possible fix

Hello there,

i get the following error when I want to visit the post-sitemap.xml generated by RankMath:
Call to a member function get_entities() on null
Unfortunately I am not able to get a stack trace or anything, but there are only 2 occurrences in your code of that function call.

If you add this after line 168 in module.third_party_compat.php:

            if ($displayed_gallery == null) {
                continue;
            }

And change line 206 in module.attach_to_post.php to:

if (in_array('image', $source_obj->returns) && $displayed_gallery != null) {

The error is gone and these checks should not break any other code. Is it possible for you to integrate that code within your code base? This would be really awesome.

Best Regards

Nils