[REG: 4-5] popup of QComboBox is shown on wrong screen in multi screen setups

To reproduce, you need to have each monitor to not be part of the same virtual desktop. For example, you could use Xephyr to simulate this:

 Xephyr +extension RANDR -screen 720x900 -screen 720x900 -ac :2 

Then run attached example and try to open combobox menu.