anchor.diff:  When there is no next buffer, go to the first one so as to cycle."
     (labels ((buffer-first-root (buffer)
                (alex:if-let ((parent (buffer-parent buffer)))
  -                          (buffer-first-root parent)
  -                          (first (first (buffer-siblings buffer)))))
  +               (buffer-first-root parent)
  +               (first (first (buffer-siblings buffer)))))
              (buffer-next-parent-sibling (buffer)
                (alex:when-let ((parent (buffer-parent buffer)))
  -                            (alex:if-let ((next-siblings (second (buffer-siblings parent))))
  -                                         (first next-siblings)
  -                                         (buffer-next-parent-sibling parent))))
  +               (alex:if-let ((next-siblings (second (buffer-siblings parent))))
  +                 (first next-siblings)
  +                 (buffer-next-parent-sibling parent))))
              (buffer-sibling-next (&optional (buffer (current-buffer)))
                (first (second (buffer-siblings buffer)))))
       (alex:when-let ((next (or (first (buffer-children buffer))
                                 (buffer-sibling-next buffer)
                                 (buffer-next-parent-sibling buffer)
                                 (buffer-first-root buffer))))
  -                   (set-current-buffer next))))
  +      (set-current-buffer next))))
   
   (define-command switch-buffer-last ()
     "Switch to the last visited buffer.
  
positive.code:   (ffi-buffer-evaluate-javascript
     buffer
     (ps:ps
      (defvar nyxt-identifier-counter 0)
      (defun add-nyxt-identifiers (node)
        (unless (ps:chain node (has-attribute "nyxt-identifier"))
          (ps:chain node (set-attribute "nyxt-identifier" (ps:stringify nyxt-identifier-counter))))
        (incf nyxt-identifier-counter)
        (dolist (child (ps:chain node children))
          (add-nyxt-identifiers child))
        nyxt-identifier-counter)
      (setf nyxt-identifier-counter (add-nyxt-identifiers (ps:chain document body)))))
    (alex:when-let ((body-json (nyxt/dom::get-document-body-json)))
                   (setf (document-model buffer)
                         (nyxt/dom::named-json-parse body-json))))
  
  (defun dead-buffer-p (buffer) ; TODO: Use this wherever needed.
    (str:empty? (id buffer)))
  
negative.code:   (unless no-history-p
      ;; Register buffer in global history:
      (files:with-file-content (history (history-file buffer)
                                :default (make-history-tree buffer))
        ;; Owner may already exist if history was just created with the above
        ;; default value.
        (unless (htree:owner history (id buffer))
  