Is there a way to filter out QWebPage::Back?

Cannot comment on https://bugreports.qt-project.org/browse/QTWEBKIT-392, here is summary:

In webkit-based GUIs, it's important that a webpage does not go back if Backspace is pressed. The only sensible way to disable back moves is to inherit from QWebPage and handle QWebPage::Back in a triggerAction() overload.

I tried it on 4.8.5, and it worked on the first page opened, but on other pages, e.g. if I follow a hyperlink, the triggerAction() overload is not called at all and page is rewinded to previous item in history.

Is it a bug? If not, what is the reason?