PHP Warning: Attempt to read property “post_content”

This may not be a very practical example, but when previewing a post with no content in the post edit screen, the following error is logged on the server, even if no shortcodes are set:

PHP Warning: Attempt to read property “post_content” on null in /home/production/www/mydomain.com/wp-content/plugins/table-of-contents-plus/includes/class-toc-plus.php on line 1533

The relevant part seems to be the following:

$custom_toc_position = has_shortcode( $post->post_content, 'toc' );

Another cause seems to be that “Attempt to read property ‘—-‘ on null” has become a warning in PHP 8.0.

Personally, I believe the error will not be logged if the following code is added before the above line:

if ( !isset( $post->post_content ) ) {
return false;
}

Thank you in advance for your assistance.