QDesktopWidget::screen() returns wrong geometry when the right screen is primary under MacOS X

I have a desktop with 2 screens. When the right screen (or bottom) is the primary screen, QDesktopWidget::screen(), which should have the geometry of the entire virtual desktop, has wrong geometry. However, this problem doesn't occur when the primary screen is the left or top screen.

I attached two screenshots where we can see the screen configuration an a test program which shows the height and width of QDesktopWidget::screen().