(i copied this from here because it somehow escaped from getting migrated)
… is the idea! If the addon is there, then the test request gets successfully fulfilled, and I know I can redirect to the safe network. If I had an error, I know there’s no point to even try. TADA! problem solved
Mirror, as in, showing the same contents. How I do it (duplicate or proxied) is really outside of the scope of what I was talking about.
I just showed a super easy way to have a site do the right thing on the safe network, but have it accessible through the old internet as well, for the time being. I know it’s a sinful desire in the eyes of many to compromise just for reaching a few hundred million more potential users, but those who are willing to live with the stigma, here’s a way to lessen the pain. Simple as that.