emacs: have doc-view-open-text remember correct page

doc-view.el

(defadvice doc-view-open-text (around
                                    su/advice/doc-view/doc-view-open-text/around/goto-page
                                    last a c pre)
       "grab the page when in doc-view mode and ensure that doc-view-open-text
        opens the correct page"
       (let ((su/dv/page (doc-view-current-page))
             (su/dv/text-buffer-name (concat "Text contents of " (buffer-name))))
         ad-do-it
         (with-current-buffer su/dv/text-buffer-name
          (re-search-forward "" nil t (1- su/dv/page))
          (recenter-top-bottom 0))))