Ticket #22413: 22413.patch

wp-includes/post-template.php

@@ -267 +267 @@
                 return __( 'There is no excerpt because this is a protected post.' );
         }
 
-        return apply_filters( 'get_the_excerpt', $post->post_excerpt );
+        $post_excerpt = isset( $post->post_excerpt ) ? $post->post_excerpt : '';
+
+        return apply_filters( 'get_the_excerpt', $post_excerpt );
 }
 
 /**