Qt reports same color depth on virtual-desktop systems even if screens have different depth

On a dual-head Windows system, configure the first screen to 32bpp and the second screen to 16bpp. The following code prints 32 both times:

qDebug() << app.desktop()>screen(0)>depth();
qDebug() << app.desktop()>screen(1)>depth();

Both times GetDeviceCaps(BITSPIXEL) is called with the global device context (i.e. qt_win_display_dc), and hence returns the same value.