not all the new window target is `_blank`

[jcyuan]

nextjs-toploader/src/index.tsx

Line 244 in 461a78d

const isExternalLink = (anchor as HTMLAnchorElement).target === '_blank';

this line has bug, because i can set my link as <a href="/page" target="_rules" /> so that all the links with this target won't open too many new windows and they will be opened in the same new window, _rules is like a target window name.

now all my '_rules' links will trigger the progress bar to show.

[WenLonG12345]

Hi, I also face issues on this as well, but for my case my target is always _self.
I think we have to double check the url with its current domain.

 const isExternalLink =
            anchorEl?.target !== '' ||
            new URL(anchorEl?.href, window?.location?.href)?.origin !==
              window?.location?.origin;

My apporoach works in my usecase. But do I miss out anythinig? If this idea is ok, should I raise a PR on this?

@jcyuan @TheSGJ