}
		if !p.consume(',') {
			return nil, errors.New("mail: expected comma")
		}
	}
	return group, nil
}

// consumeAddrSpec parses a single RFC 5322 addr-spec at the start of p.
func (p *addrParser) consumeAddrSpec() (spec string, err error) {
	debug.Printf("consumeAddrSpec: %q", p.s)

	orig := *p
	defer func() {
		if err != nil {
			*p = orig
		}
	}()