class TestVariantBug : public QObject
{
    Q_OBJECT
public:
    explicit TestVariantBug(QObject *parent = 0) :
        QObject(parent)
    {
    }
    Q_INVOKABLE QVariantMap create()
    {
        QVariantMap result;
        result["dest"] = QStringList() << "test";
        return result;
    }
    Q_INVOKABLE QVariantMap test(QVariantMap map)
    {
        qDebug() << "C++ Map:" << map;
        return map;
    }
};

TestVariantBug{
    id:bug
    Component.onCompleted: {
        var x = bug.create();
        bug.test(x)
    }
}