+
+ /**
+ * Filter whether a post has changed.
+ *
+ * By default a revision is saved only if one of the revisioned fields has changed.
+ * This filter allows for additional checks to determine if there were changes.
+ *
+ * @since 4.1.0
+ *
+ * @param bool $post_has_changed Whether the post has changed.
+ * @param WP_Post $last_revision The last revision post object.
+ * @param WP_Post $post The post object.
+ *
+ */
+ $post_has_changed = (bool) apply_filters( 'wp_save_post_revision_post_has_changed', $post_has_changed, $last_revision, $post );
+