Ticket #40547: 40547.2.diff

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

@@ -227 +227 @@
                 return false;
         }
 
-        return wp_get_attachment_image_url( $post_thumbnail_id, $size );
+        $thumbnail_url = wp_get_attachment_image_url( $post_thumbnail_id, $size );
+
+        /**
+         * Filters the post thumbnail URL.
+         *
+         * @since 5.9.0
+         *
+         * @param string|false     $thumbnail_url Post thumbnail URL or false if the post does not exist.
+         * @param int|WP_Post|null $post          Post ID or WP_Post object. Default is global `$post`.
+         * @param string|int[]     $size          Registered image size to retrieve the source for or a flat array
+         *                                        of height and width dimensions. Default 'post-thumbnail'.
+         */
+        return apply_filters( 'post_thumbnail_url', $thumbnail_url, $post, $size );
 }
 
 /**