(defun gnus-dup-unsuppress-article (article)
"Stop suppression of ARTICLE."
- (let ((id (mail-header-id (gnus-data-header (gnus-data-find article)))))
+ (let* ((header (gnus-data-header (gnus-data-find article)))
+ (id (when header (mail-header-id header))))
(when id
(setq gnus-dup-list-dirty t)
(setq gnus-dup-list (delete id gnus-dup-list))