- (let ((ctype (notmuch-split-content-type
- (downcase (plist-get part :content-type)))))
- (cond ((equal (car ctype) "multipart")
+ (pcase-let ((`(,content ,type)
+ (split-string (downcase (plist-get part :content-type)) "/")))
+ (cond ((equal content "multipart")