If there are two linebreaks at the end of a file, keep them, if there's only one it is kept as is to not add extra changes to commits.

maybe-remove-newlines

(defun delete-trailing-whitespace-and-extra-nl ()
  (interactive)
  (let ((two? (ends-with-two-linebreaks?)))
    (progn
      (delete-trailing-whitespace)
      (if (and two? (string-match "silk" (buffer-file-name)))
        (save-excursion
          (let ((undo-list (undo-copy-list buffer-undo-list)))
            (progn
              (buffer-disable-undo)
              (goto-char (point-max))
              (insert ?\n)
              (buffer-enable-undo)
              (setq buffer-undo-list undo-list)
              (set-buffer-modified-p nil)
              )))))))
(defun ends-with-two-linebreaks? ()
  (equal '(?\n ?\n)
         (list (char-before (point-max))
               (char-before (1- (point-max)))
               )))