Ticket #13091: 13091-opt2.patch

comment.php

@@ -1348 +1348 @@
         do_action('wp_set_comment_status', $comment_id, $comment_status);
         wp_transition_comment_status($comment_status, $comment_old->comment_approved, $comment);
 
-        wp_update_comment_count($comment->comment_post_ID);
+        if($status == '1' || $comment_old->comment_approved == 1) // then a comment has changed to/from approved
+                wp_update_comment_count($comment->comment_post_ID);
 
         return true;
 }