header.go
func fixUnquotedSpecials(s string) string {
	idx := strings.IndexByte(s, ';')
	if idx < 0 || idx == len(s) {
		// No parameters
		return s
	}

	clean := strings.Builder{}
	clean.WriteString(s[:idx+1])
	s = s[idx+1:]

	for len(s) > 0 {
		var consumed string
		consumed, s = consumeParam(s)

		if len(consumed) == 0 {
			clean.WriteString(s)
			return clean.String()
		}

		clean.WriteString(consumed)
	}

	return clean.String()
}
func fixUnquotedSpecials(s string) string {
	idx := strings.IndexByte(s, ';')
	if idx < 0 || idx == len(s) {
		// No parameters
		return s
	}

	clean := strings.Builder{}
	clean.WriteString(s[:idx+1])
	s = s[idx+1:]

	for len(s) > 0 {
		var consumed string
		consumed, s = consumeParam(s)

		if len(consumed) == 0 {
			clean.WriteString(s)
			return clean.String()
		}

		clean.WriteString(consumed)
	}

	return clean.String()
}
// fixUnquotedSpecials as defined in RFC 2045, section 5.1:
// https://tools.ietf.org/html/rfc2045#section-5.1