(defun notmuch-show-add-tags-worker (current-tags add-tags)
"Add to `current-tags' with any tags from `add-tags' not
currently present and return the result."
(defun notmuch-show-add-tags-worker (current-tags add-tags)
"Add to `current-tags' with any tags from `add-tags' not
currently present and return the result."