def parse_colon_dict(data):
    """
    Parse colon seperated values into a dictionary, treating lines
    lacking a colon as continutation lines.

    Any leading lines without a colon will be associated with the key
    ``None``.

    This is the format output by ``rpm --query`` and ``dpkg --info``.

    :param bytes data: Data to parse
    :return: A ``dict`` containing the parsed data.
    """
    result = {}
    key = None
    for line in data.splitlines():
        parts = [value.strip() for value in line.split(':', 1)]
        if len(parts) == 2:
            key, val = parts
            result[key] = val
        else:
            result.setdefault(key, '')
            result[key] += parts[0]
    return result