Scale displayed incorrectly

[Crowley]

I think I discovered a bug in the way that the scale is displayed.

I have an example program with a bare QwtPlot and a checkbox that sets/clears the attribute QwtScaleEngine::Floating for the x axis. Here is the code:

QtDialogTest::QtDialogTest(QWidget* parent)
	: QDialog(parent)
{
	ui.setupUi(this);
	Populate();
	ui.plot->setAxisAutoScale(QwtPlot::xBottom);
	connect(ui.enableFloatingAttributecheckBox, &QCheckBox::stateChanged, this, &QtDialogTest::EnableFloatingAttribute);
}
 
void QtDialogTest::EnableFloatingAttribute(int state)
{
	bool enable = (state == Qt::Checked);
	ui.plot->axisScaleEngine(QwtPlot::xBottom)->setAttribute(QwtScaleEngine::Floating, enable);
	ui.plot->replot();
}
 
void QtDialogTest::Populate()
{
	QVector<QPointF> samples{ QPointF(1000.4, 1.0), QPointF(1001.4, 1.5), QPointF(1001.7, 2.0), QPointF(1001.9, 1.5), QPointF(1002.05, 1.0) };
	auto curve = new QwtPlotCurve;
	curve->setSamples(samples);
	QBrush brush(QColor::fromRgb(255, 0, 0));
	QPen pen(QColor::fromRgb(128, 0, 0));
	curve->setSymbol(new QwtSymbol(QwtSymbol::Ellipse, brush, pen, QSize(8, 8)));
	curve->setPen(pen);
	curve->attach(ui.plot);
}

QtDialogTest::QtDialogTest(QWidget* parent)
	: QDialog(parent)
{
	ui.setupUi(this);
	Populate();
	ui.plot->setAxisAutoScale(QwtPlot::xBottom);
	connect(ui.enableFloatingAttributecheckBox, &QCheckBox::stateChanged, this, &QtDialogTest::EnableFloatingAttribute);
}

void QtDialogTest::EnableFloatingAttribute(int state)
{
	bool enable = (state == Qt::Checked);
	ui.plot->axisScaleEngine(QwtPlot::xBottom)->setAttribute(QwtScaleEngine::Floating, enable);
	ui.plot->replot();
}

void QtDialogTest::Populate()
{
	QVector<QPointF> samples{ QPointF(1000.4, 1.0), QPointF(1001.4, 1.5), QPointF(1001.7, 2.0), QPointF(1001.9, 1.5), QPointF(1002.05, 1.0) };
	auto curve = new QwtPlotCurve;
	curve->setSamples(samples);
	QBrush brush(QColor::fromRgb(255, 0, 0));
	QPen pen(QColor::fromRgb(128, 0, 0));
	curve->setSymbol(new QwtSymbol(QwtSymbol::Ellipse, brush, pen, QSize(8, 8)));
	curve->setPen(pen);
	curve->attach(ui.plot);
}

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When the plot is displayed, everything seems ok (see attached file ScaleOk.png). However, when I reduce the size of the plot, the scale is not displayed correctly anymore (see attached file ScaleWrong.png). I guess the plot attempts to display the leftmost label of the scale and - correctly - reduced the space between the ticks. But since the leftmost data point has a value of 1000.4, which also is the value of the leftmost minor tick, these two are not displayed correctly to each other anymore.

Can you perhaps provide a short-term bugfix for this?