Get the popup mouse position for the right screen

If the parent window of the popup is not on the primary screen
use the right one to get the mouse position.

Change-Id: Ib9929e6fdf90dfae2457486edc9504719bdaad8b
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@digia.com>

src/controls/qquickmenu.cpp

@@ -367,14 +367,16 @@ QQuickWindow *QQuickMenu::findParentWindow()
 
 void QQuickMenu::popup()
 {
-    QPoint mousePos = QCursor::pos();
+    QQuickWindow *parentWindow = findParentWindow();
+    QScreen *screen = parentWindow ? parentWindow->screen() : qGuiApp->primaryScreen();
+    QPoint mousePos = QCursor::pos(screen);
 
     if (mousePos.x() == int(qInf())) {
         // ### fixme: no mouse pos registered. Get pos from touch...
-        mousePos = qGuiApp->primaryScreen()->availableGeometry().center();
+        mousePos = screen->availableGeometry().center();
     }
 
-    if (QQuickWindow *parentWindow = findParentWindow())
+    if (parentWindow)
         mousePos = parentWindow->mapFromGlobal(mousePos);
 
     __popup(QRectF(mousePos.x(), mousePos.y(), 0, 0));