Wrong mapping between QFileDialog's filters and QImageWriter mime types

#include <QApplication>

#include <QFileDialog>
#include <QImageWriter>
#include <QMessageBox>
#include <QStandardPaths>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    const QString format = "png";
    QString initialPath = QStandardPaths::writableLocation(QStandardPaths::PicturesLocation);
    if (initialPath.isEmpty())
        initialPath = QDir::currentPath();
    initialPath += QObject::tr("/untitled.") + format;

    QFileDialog fileDialog(nullptr, QObject::tr("Save As"), initialPath);
    fileDialog.setAcceptMode(QFileDialog::AcceptSave);
    fileDialog.setFileMode(QFileDialog::AnyFile);
    fileDialog.setDirectory(initialPath);
    QStringList mimeTypes;
    const QList<QByteArray> baMimeTypes = QImageWriter::supportedMimeTypes();
    for (const QByteArray &bf : baMimeTypes)
        mimeTypes.append(QLatin1String(bf));
    fileDialog.setMimeTypeFilters(mimeTypes);
    fileDialog.selectMimeTypeFilter("image/" + format);
    fileDialog.setDefaultSuffix(format);
    if (fileDialog.exec() != QDialog::Accepted)
        return EXIT_SUCCESS;
    const QString fileName = fileDialog.selectedFiles().first();
    return a.exec();
}