gnus-bug-ticket-cookie.el

(defun vz/gnus-vc-log-insert-bug-number ()
  "Insert bug number of thread at point to *vc-log* buffer."
  (interactive nil gnus-summary-mode)
  (unless (get-buffer "*vc-log*")
    (user-error "*vc-log* buffer not found"))
  (unless (eq gnus-current-article (gnus-summary-article-number))
    (gnus-summary-select-article))
  (with-current-buffer gnus-original-article-buffer
    (save-restriction
      (article-narrow-to-head)
      (let* ((address (nconc (ensure-list (message-fetch-field "to"))
                             (ensure-list (message-fetch-field "from"))
                             (ensure-list (message-fetch-field "cc"))))
             (donep nil))
        (while (and (null donep) address)
          (pcase (car address)
            ((rx (group (+ (any (?0 . ?9)))) "@debbugs.gnu.org")
               (with-current-buffer (get-buffer "*vc-log*")
                 (insert " (Bug#" (match-string 1 (car address)) ")"))
               (setq donep t))
            ((rx "emacs-orgmode@gnu.org")
               (let* ((id (message-fetch-field "message-id"))
                      (root (with-current-buffer gnus-summary-buffer
                              (gnus-id-to-header (gnus-root-id id)))))
                 (when (or root root-headers)
                   (with-current-buffer (get-buffer "*vc-log*")
                     (goto-char (point-max))
                     (insert "\n\n")
                     (insert "Reported-by: " (mail-header-from root) "\n")
                     (insert "Link: https://list.orgmode.org/"
                             (substring (mail-header-id root) 1 -1)))
                   (setq donep t)))))
          (setq address (cdr address)))
        (if (null donep)
            (user-error "Could not find any bug number")
          (message "Inserted bug number to *vc-log* buffer"))))))