So much window flags are not accepted / working on Win32 / Windows 7

In following code:

QWidget *w = new QWidget;
w->setWindowFlags(Qt::WindowDoesNotAcceptFocus | Qt::FramelessWindowHint);
w->setAttribute(Qt::WA_ShowWithoutActivating);
w->show();

The window still steals focus when clicked. I am unable to implement my popups (They worked nice in 4.8)

Also I have very big problems with Qt::FramelessWindowHint and Qt::WA_TranslucentBackground, most commonly windows not showing at all unless I call these BEFORE ui->SetupUi. It looks like EnsurePolished() breaks them.

Qt::Popup | Qt::NoDropShadowWindowHint should also be respected on Win32.

How can I implement popup-like top-level frameless window that does not steal focus from its owner top-level window without using Win32/SetClassLong on it?