Using master (98958c81f5065a5de13699d46995d278ecb6709e) with Qt `5.12.3` (also tested with depends) with multiple wallets available. None are shown in the `Open Wallet ->` menu in the gui. The wallets can be loaded from the console, bitcoin-cli etc.
{
    if (m_node.shutdownRequested())
    {
        if(rpcConsole)
            rpcConsole->hide();
        qApp->quit();
    }
}
void BitcoinGUI::showProgress(const QString &title, int nProgress)
{
    if (nProgress == 0) {
        progressDialog = new QProgressDialog(title, QString(), 0, 100);
        GUIUtil::PolishProgressDialog(progressDialog);
        progressDialog->setWindowModality(Qt::ApplicationModal);
        progressDialog->setMinimumDuration(0);
        progressDialog->setAutoClose(false);
        progressDialog->setValue(0);
    } else if (nProgress == 100) {
        if (progressDialog) {
            progressDialog->close();
            progressDialog->deleteLater();
            progressDialog = nullptr;
        }
    } else if (progressDialog) {
        progressDialog->setValue(nProgress);
    }
}
void BitcoinGUI::setTrayIconVisible(bool fHideTrayIcon)