Code review comment for lp://qastaging/~daker/webbrowser-app/fix.1317428

11 + if (invalid_hostname_characters.match(address)){
12 + return false
13 + }

It doesn’t seem correct to me to apply the invalid_hostname_characters RE to the entire address: you’d want to apply it to the host part only. But since we don’t really know whether address is a valid URl yet, there’s no easy way to extract the host part. So I’m not sure this makes sense.