Ticket #19395: 19395.diff

wp-includes/pluggable.php

@@ -980 +980 @@
         $post    = get_post( $comment->comment_post_ID );
         $author  = get_userdata( $post->post_author );
 
+        // The post author is no longer a member of the blog
+        if ( ! is_user_member_of_blog( $post->post_author ) )
+                return false;
+
         // The comment was left by the author
         if ( $comment->user_id == $post->post_author )
                 return false;