The attached example can be used to reproduce the crash:

#include <QApplication>
#include <QWidget>
#include <QScopedPointer>

int main(int argc, char **argv)
{
    QApplication *app = new QApplication(argc, argv);
    //QScopedPointer<QApplication> app(new QApplication(argc, argv));

    QWidget widget;
    widget.show();
    return app->exec();
}

Steps to reproduce:
1. Run the attached example application
2. close the window
3. repeat if you don't see a seg fault

Expected result:
No segmentation fault should happen

Actual result:
There comes a segmentation fault around every 7th time.

As a workaround one can use QScopedPointer instead of QApplication to prevent it from crashing if the QApplication is created from heap.