When rendering a large image inside a QRect with QPainter::drawImage onto a QQuickPaintedItem which was set up the following way:
after a certain size of the target QRect, the image renders as a black rectangle instead of the required image.
If the render target is not QQuickPaintedItem::FramebufferObject the image drawing performs as expected.
The issue has been observed on both Linux and Windows platforms, with graphics cards using both Nivida and Intel chipsets.
In the attached test application supplying a scale more than 0.6 will trigger this behaviour.