Crash on QFuture::cancel() with continuation and thread context

#include <QCoreApplication>
#include <QtConcurrent/QtConcurrent>

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);

    auto future = QtConcurrent::run( []{});

    // if the future of the continuation
    // is kept alive by storing into a
    // local variable, the cancel later works fine
    /*auto cont_future =*/ future.then(&a, [](){});

    future.waitForFinished();
    QEventLoop().processEvents();
    future.cancel();                             // crash here.

    return 0;
}