Ticket #44859: 44859.2.diff

src/wp-includes/post-thumbnail-template.php

@@ -23 +23 @@
  * @return bool Whether the post has an image attached.
  */
 function has_post_thumbnail( $post = null ) {
-        return (bool) get_post_thumbnail_id( $post );
+        $thumbnail_id  = get_post_thumbnail_id( $post );
+        $has_thumbnail = (bool) $thumbnail_id;
+
+        /**
+         * Filters whether a post has a post thumbnail.
+         *
+         * @since 5.1.0
+         *
+         * @param bool             $has_thumbnail true if the post has a post thumbnail, otherwise false.
+         * @param int|WP_Post|null $post          Post ID or WP_Post object. Default is global `$post`.
+         * @param int|string       $thumbnail_id  Post thumbnail ID or empty string.
+         */
+        return (bool) apply_filters( 'has_post_thumbnail', $has_thumbnail, $post, $thumbnail_id );
 }
 
 /**