QFileDialog::getOpenFileName crashes with heap-use-after-free

As seen in "BugTest.txt", AddressSanitizer reports a "heap-use-after-free" when this line is called:

filename=QFileDialog::getOpenFileName(this, tr("Open"), QString(), tr("Files (.)"));

Adding the home directory as a location suggestion makes no difference. This worked fine in Qt 5.7.0 and some versions before. I made a simple test case to show that it crashes with Debug and Release 5.8.0 and works with Debug and Release 5.7.0. It might be a GTK issue, somehow.