def create_mp_description(description_format, lines):
    """Create a merge proposal description.

    Args:
      lines: List of one-line descriptions of fixes
    Returns:
      A string with a merge proposal description
    """
    if len(lines) > 1:
        mp_description = ['Fix some issues reported by lintian\n']
        for line in lines:
            line = '* %s\n' % line
            if line not in mp_description:
                mp_description.append(line)
    else:
        mp_description = lines[0]
    return ''.join(mp_description)
