(if (string= petname old-petname)
nil
(if (or (rassoc petname wl-folder-petname-alist)
- (wl-string-assoc petname wl-folder-group-alist))
+ (and is-group
+ (wl-string-assoc petname wl-folder-group-alist)))
(message "%s: already exists" petname)
(wl-folder-append-petname name petname)
(setq change t)))))