Trying to get property ‘comment_status’ of non-object

The plugin throw following error:

PHP Notice: Trying to get property ‘comment_status’ of non-object in /Users/robinferrari/Documents/web/Perso/auberceaudor/.www/wp-includes/comment-template.php on line 1244

This is due to hwwa_css_comments_wordpress function

instead doing
if(comments_open)

it should be
if ( function_exists('comments_open') && function_exists('get_post') && get_post() && comments_open() ) {

Here is a patch function to place in theme or plugin:

function patch_hwwa_css_comments_wordpress() {
  if ( function_exists('comments_open') && function_exists('get_post') && get_post() && comments_open() ) {
    ?>
 <style type="text/css">
 .hwwa_field {
  display: none !important;
 }
 </style>
<?php }
}
remove_action( 'wp_head', 'hwwa_css_comments_wordpress');
add_action('wp_head', 'patch_hwwa_css_comments_wordpress');