Long press from touch screen is handled different from long mouse press

[Marc_Van_Daele]

We have a website that uses long-presses. When accessing this website from a WebEngineView in QML, we note that

• a long-mouse-press is handled correctly
• a long-touch-press gets translated to a right click

Note that we see the same behavior when accessing this webpage directly from Chromium. It works fine when opening this webpage from Firefox.

I assume that this happens because the long-touch-presses have mouse.source=Qt.MouseEventSynthesizedByQt while long-mouse-presses have mouse.source==Qt.MouseEventNotSynthesized

So I would like to make this webpage work in WebEngineView .
Which options do you see?

One option I see is to recompile Qt and remove MouseEventSynthesizedByQt. This is new to me so what is the best/suggested approach here?
Change (in qevent.cpp)

Qt::MouseEventSource QMouseEvent::source() const
{
    return Qt::MouseEventNotSynthesized; //QGuiApplicationPrivate::mouseEventSource(this);
}

or replace the limited number (< 10) of occurences where MouseEventSynthesizedByQt is used by MouseEventNotSynthesized?