def _decode_unknown_from_base64(path, bcontent):
    """
    Decode base64 data of unknown format.

    Attempts to interpret data as utf-8, falling back to ascii on failure.
    """
    content = b64decode(bcontent)
    try:
        return (content.decode('utf-8'), 'text')
    except UnicodeError:
        pass
    return bcontent.decode('ascii'), 'base64'
Decode base64 data of unknown format.

    Attempts to interpret data as utf-8, falling back to ascii on failure.