anchor.diff:      (let ((button (button-at p)))
         (when button
           (button-action button)))))
  +
  +(add-hook *after-init-hook*
  +          (lambda ()
  +            (when (variable-value 'tabbar :global)
  +              (tabbar-init))))
  
positive.code:   (setf (tabbar-prev-display-width *tabbar*) 0))
    
  (defun tabbar-off ()
    (when *use-tabbar*
      (setf *use-tabbar* nil)
      (tabbar-clear-cache)
      (delete-window *tabbar*)
      (setf *tabbar* nil)))
    
  (defun tabbar-on ()
    (unless *use-tabbar*
      (setf *use-tabbar* t)
      (tabbar-init)))
  
  (defun enable-tabbar-p ()
    *use-tabbar*)
  
  (define-command toggle-tabbar () ()
    (if (enable-tabbar-p)
        (tabbar-off)
        (tabbar-on)))
  
  (define-key *global-keymap* (list (code-char 550)) 'tabbar-next) ; control + pagedown
  (define-key *global-keymap* (list (code-char 555)) 'tabbar-prev) ; control + pageup
  
negative.code:   (:use :cl :lem :lem.button)
    (:export :tabbar-active-tab-attribute
             :tabbar-attribute
             :tabbar-background-attribute
             :tabbar))
  (in-package :lem.tabbar)
  
  (define-attribute tabbar-active-tab-attribute
  