Infinite filling area curve

[SandyEmerald]

Hi all. I'm using qwt 5.2.2. I'm trying to make kind of filling area between two lines. Lines can be infinite in horizontal. I'm using DBL_MIN and DBL_MAX.
Lines are inherit from QwtPlotMarker. If my lines are infinite, I create them using setYValue(double), if not - setValue(double, double).
Code for my filling area:

QwtPlotCurve* fillingAreaCurve = new QwtPlotCurve;
 
    fillingAreaCurve->setItemAttribute(QwtPlotItem::Legend, false);
    fillingAreaCurve->setStyle(QwtPlotCurve::Lines);
    fillingAreaCurve->setPen(QPen(Qt::gray, 1, Qt::SolidLine));
    fillingAreaCurve->setBrush(QBrush(QColor(150, 150, 150, 127),Qt::SolidPattern));
    fillingAreaCurve->setBaseline(baseline);
    fillingAreaCurve->setData(xData, yData, 2);

QwtPlotCurve* fillingAreaCurve = new QwtPlotCurve;

    fillingAreaCurve->setItemAttribute(QwtPlotItem::Legend, false);
    fillingAreaCurve->setStyle(QwtPlotCurve::Lines);
    fillingAreaCurve->setPen(QPen(Qt::gray, 1, Qt::SolidLine));
    fillingAreaCurve->setBrush(QBrush(QColor(150, 150, 150, 127),Qt::SolidPattern));
    fillingAreaCurve->setBaseline(baseline);
    fillingAreaCurve->setData(xData, yData, 2);

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Where xData is array, xData[0] = DBL_MIN, xData[1] = DBL_MAX. After that, i do attach(plot) and replot().
The problem is that my program freeze. I tried to separate them to two areas - from DBL_MIN to 0 and from 0 to DBL_MAX - nothing changed.
Any ideas?

P.S.: Sorry for my horrible English.