anchor.diff:  
   (defun history-forwards-all-suggestion-filter (&optional (buffer (current-buffer)))
     "Suggestion function over children URL from all branches."
  -  (let ((children (remove-if #'(lambda (node)
  -                                 (and (conservative-history-movement buffer)
  -                                      (string/= (id (htree:data node)) (id buffer))))
  -                             (htree:children-nodes (get-data (history-path buffer))))))
  +  (let ((children (conservative-history-filter
  +                   buffer (htree:children-nodes (get-data (history-path buffer))))))
       (lambda (minibuffer)
         (if children
             (fuzzy-match (input-buffer minibuffer) children)
  
positive.code:                 (id (htree:data history-node)) (id buffer))
            (buffer-load (url (htree:data history-node)))))))
  
  (define-command history-backwards (&optional (buffer (current-buffer)))
    "Go to parent URL in history."
    (with-data-access (history (history-path buffer))
      (let ((parents (remove-if #'(lambda (node)
                                    (and (conservative-history-movement buffer)
                                         (string/= (id (htree:data node)) (id buffer))))
                                (htree:parent-nodes history))))
        (if parents
            (set-url-from-history (first parents) buffer)
            (echo "No backward history.")))))
  
negative.code: 
  (defun history-all-suggestion-filter (&optional (buffer (current-buffer)))
    "Suggestion function over all history URLs."
    (let ((urls (conservative-history-filter
                 buffer (htree:all-nodes (get-data (history-path buffer))))))
      (lambda (minibuffer)
        (if urls
            (fuzzy-match (input-buffer minibuffer) urls)
  