[QtQuickTest] Calling grabImage() will crash the application when window is not shown

Hi,

I would like to report two problems about QtQuickTest. I think it should be more easy to explain by source code:

tst_grabImage.qml :

import QtQuick 2.0
import QtTest 1.0

Rectangle {
    id : win
    width: 480
    height: 640
    color : "black";

    TestCase {
        function test_basic(){
            wait(10000);
            var image = grabImage(win);
        }

    }

}

The code is executed by quick_test_main() function.

Expectation:

1) A window should be launched with a black rectangle

2) After 10s, it will grab the image

The result:
1) No window is shown.

2) The application crash after 10s called grabImage()