"basic URL parser" doesn't special-case the empty string as input

[GPHemsley]

If input to "basic URL parser" is the empty string, the algorithm is able to make it all the way through to the end, since there is no special check for empty string. That essentially means it returns a URL with all default values.

If that URL is then passed to "URL serializer", it returns : (just U+003A (:)).

Is this all expected behavior? It seems to me like it wouldn't be.

[GPHemsley]

Nevermind, the algorithm correctly transitions from "scheme start state" to "no scheme state" (where it fails if there is no base) to "relative state" (where it sets everything to match the base).

My implementation was wrong.