QFileDialog does not use passed name

QFileDialog does not use specified file name.

If using static method QFileDialog::getSaveFileName in this way:

---------------------
QString fileName = tr("foo.csv");
fileName = QStandardPaths::writableLocation(QStandardPaths::DocumentsLocation) +
QLatin1String("/") + fileName;

return QFileDialog::getSaveFileName
(
widget,
tr("Please, select export file name"),
fileName,
tr("Csv files (.csv);;All files (.*)")
);
---------------------

we will not see specified file name in dialog. But if we will tune file dialog with option QFileDialog::DontUseNativeDialog

-----------
QString fileName = tr("foo.csv");
fileName = QStandardPaths::writableLocation(QStandardPaths::DocumentsLocation) +
QLatin1String("/") + fileName;

return QFileDialog::getSaveFileName
(
widget,
tr("Please, select export file name"),
fileName,
tr("Csv files (.csv);;All files (.*)"),
0,
QFileDialog::DontUseNativeDialog
);
-----------

we will able to see specified name.

Previously, my application was based on Qt 4.8.4. And, as I remember, I was able to use native dialog and specify file name in the same time.

Sorry for my English.