Make illegal character sanitization more robust about gofeed HOT 1 OPEN

func convertToUTF8(data []byte) (string, error) {
	reader, err := charset.NewReader(bytes.NewReader(data), "")
	if err != nil {
		return "", err
	}
	utf8Data, err := ioutil.ReadAll(reader)
	if err != nil {
		return "", err
	}
	return string(utf8Data), nil
}

func sanitizeXML(xmlData []byte) (string, error) {
	utf8Data, err := convertToUTF8(xmlData)
	if err != nil {
		utf8Data = string(xmlData) // Fallback to original data if conversion fails
	}

	var buffer bytes.Buffer

	for _, r := range utf8Data {
		if isLegalXMLChar(r) {
			buffer.WriteRune(r)
		} else {
			buffer.WriteString(fmt.Sprintf("&#x%X;", r))
		}
	}

	return buffer.String(), nil
}