bool QObject::disconnect(const QObject *sender, const char *signal,
                         const QObject *receiver, const char *method)
{
    if (sender == nullptr || (receiver == nullptr && method != nullptr)) {
        qCWarning(lcConnect, "QObject::disconnect: Unexpected nullptr parameter");
        return false;
    }

    const char *signal_arg = signal;
    QByteArray signal_name;
    bool signal_found = false;
    if (signal) {
        QT_TRY {
            signal_name = QMetaObject::normalizedSignature(signal);
            signal = signal_name.constData();
        } QT_CATCH (const std::bad_alloc &) {

~~~~