elisp to move diff hunks to another buffer

gistfile1.scm

(defun diff-hunk-move (dest-buffer)
  "Move current hunk to another buffer."
  (interactive "bBuffer to move to:")
  (save-excursion
    (let* ((start
            (point))
           (start-of-file
            (ignore-errors
              (goto-char start)
              (diff-beginning-of-file)
              (point)))
           (first-hunk
            (ignore-errors
              (goto-char start)
              (diff-beginning-of-file)
              (diff-hunk-next)
              (point))))
      (kill-ring-save start-of-file first-hunk) ; Copy file header
      (diff-hunk-yank-in-buffer dest-buffer)
      (goto-char start) ; Copy the hunk itself
      (diff-end-of-hunk)
      (kill-ring-save start (point))
      (diff-hunk-yank-in-buffer dest-buffer))))

(defun diff-hunk-yank-in-buffer (dest-buffer)
  (let* (old-buffer (current-buffer))
    (switch-to-buffer dest-buffer)
    (end-of-buffer)
    (yank)
    (switch-to-buffer old-buffer)))