#include <QtGui>

int main(int argc, char *argv[])
{
    QGuiApplication a(argc, argv);

    QImage i(100, 100, QImage::Format_RGB32);
    i.fill(Qt::black);

    QByteArray storage;

    {
        QDataStream ds(&storage, QIODevice::WriteOnly);
        ds << i;
    }

    // simulate a short read
    storage.resize( storage.size() / 3 );

    {
        QDataStream ds(&storage, QIODevice::ReadOnly);
        QImage result;

        ds.startTransaction();
        ds >> result;
        if (ds.commitTransaction()) {
            // qFatal("Cannot happen");
            if (i != result)
                qFatal("Cannot happen");
        }
    }
}