conversion from bytearray to int produce zero

[Lykurg]

What's about

bool ok;
    QByteArray ba = QByteArray::fromHex("ffdecb7002");
    qWarning() << ba.toHex();
    qWarning() << ba.mid(2,1).toHex() << ba.mid(2,1).toHex().toInt(&ok, 16);

bool ok;
    QByteArray ba = QByteArray::fromHex("ffdecb7002");
    qWarning() << ba.toHex();
    qWarning() << ba.mid(2,1).toHex() << ba.mid(2,1).toHex().toInt(&ok, 16);

To copy to clipboard, switch view to plain text mode 

gives

"ffdecb7002"
"cb" 203

..or say what you expect.