Exporting data from DataSource, missing file extension

[hlevin]

Hi, we're on smartGWT 2.5p.

When exporting from the ListGrid, file extension is being set correctly but when directly from the DataSource, file extension is missing. The content type is identified correctly though, or so it seems.

DSRequest dsRequestProperties = new DSRequest();
dsRequestProperties.setExportAs(ExportFormat.XLS);
dsRequestProperties.setDataSource("some_ds_name");
dsRequestProperties.setExportDisplay(ExportDisplay.DOWNLOAD);
dsRequestProperties.setExportFilename("some_filename");
dsRequestProperties.setStartRow(0);
dsRequestProperties.setEndRow(50000);
                   
downloadDS.exportData(downloadCriteria, dsRequestProperties);

Is there something I am doing wrong or missing some set call? I am expecting to see the download file named: some_filename.xls but it's just some_filename.

Thanks,
Henry