Incorrect decoding

[ac169]

1. The following data will fail to decode and return empty, Lines ”0x31, 0x3a, 0x79, 0x31, 0x3a, 0x72, 0x31, 0x3a, 0x76, 0x34, 0x3a, 0x4c, 0x54, 0x01, 0x02“ can be decoded correctly when the first 6 characters are deleted or changed to the end of the line

 unsigned char msg[] = {
            0x64, 0x32, 0x3a, 0x69, 0x70, 0x36, 0x3a, 0x01, 0x17, 0x03, 0x6e, 0x71, 0xcb, 0x31, 0x3a, 0x72,
            0x64, 0x32, 0x3a, 0x69, 0x64, 0x32, 0x30, 0x3a, 0x1c, 0x11, 0xe0, 0x1b, 0xe8, 0xe7, 0x8d, 0x76,
            0x5a, 0x2e, 0x63, 0x33, 0x9f, 0xc9, 0x9a, 0x66, 0x32, 0x0d, 0xb7, 0x54, 0x65, 0x31, 0x3a, 0x74,
            0x38, 0x3a, 0x70, 0x6e, 0x5f, 0x42, 0x49, 0x36, 0x44, 0x53,
            0x31, 0x3a, 0x79, 0x31, 0x3a, 0x72, 0x31, 0x3a, 0x76, 0x34, 0x3a, 0x4c, 0x54, 0x01, 0x02,
            0x65, 0x00
    };

 struct bencode *b = (struct bencode *) ben_decode(msg, strlen(msg));

2. isprint() function does not work properly under windows.