Theoretical question here... what if a website was to have a number of 301 redirect loops, so that the redirect pointed the page back to itself? (i.e. mysite.com/mypage pointed to mysite.com/mypage) in terms of SEO.
Perhaps more importantly, what if I was to find a site with the following 301 redirect: / redirects to mysite.com, so that the home page is being redirected back to the base domain.
Would that cause the site to become delisted by search engines?
Clients (like browsers) are advised to detect infinite redirection loops, as specified in section 6.4 of RFC 7231:
Mozilla Firefox, for example, would stop trying to load the page after 20 redirects (can be configured) and display an error message.
As search engines are just normal visitors (they won’t be able to magically load the page), and it wouldn’t make sense for them to link to pages their users can’t visit anyway, they’ll probably delist these pages sooner or later.