This is wrong, it would accept all certificate errors triggered by one page, regardless of what error it is - it may even be error with completely different certificate, from different resource on page. If anything, this should only be offered to reject all certificate errors from one page, but even then it doesn't really make sense.

What should be done to fix that bug is to offer NoForThisSession similar to OnlyForThisSession with same logic. Even this logic is not really correct due to very limited QtWebEngine API here, but is good enough to be used for one browsing session (it only compares url and certificate error type).

This now just remember error type, but not url. It has to be done exactly the same as m_ignoredSslErrors - that is, store both url host and error type.