Ticket #24250: 24250.diff

wp-includes/post-template.php

@@ -1275 +1275 @@
  *
  * @since 3.4.0
  *
- * @param int $post_id The page ID to check. Defaults to the current post, when used in the loop.
+ * @param int|null $post_id The page ID to check. Defaults to the current post, when used in the loop.
  * @return string|bool Page template filename. Returns an empty string when the default page template
  *      is in use. Returns false if the post is not a page.
  */
 function get_page_template_slug( $post_id = null ) {
         $post = get_post( $post_id );
-        if ( 'page' != $post->post_type )
+        if ( ! isset( $post->post_type ) || 'page' != $post->post_type )
                 return false;
         $template = get_post_meta( $post->ID, '_wp_page_template', true );
         if ( ! $template || 'default' == $template )