QDBusPendingReply::value() crash if call fails

I had a function like this:

QDBusObjectPath Daemon::getTid()
{
    // Where CreateTransaction
    // returns a QDBusPendingReply<QDBusObjectPath>
    return d->daemon->CreateTransaction();;
}

This code crashes if the called interface is not available
because value() doesn't return a default constructed value
as it doesn't check if is valid, doing a argumentAt<0> and
there isn't such argument.

It should behave like QDBusReply::value()

Thanks.