Is a 302 redirect to relative URL valid, or invalid?
RFC 2616 requires an absolute URI in the Location
, but that standard has been replaced, since June 2014. The relevant specification is now RFC 7231. The relevant section of the new standard says:
Location = URI-reference
The field value consists of a single URI-reference. When it has the form of a relative reference ([RFC3986], Section 4.2), the final value is computed by resolving it against the effective request URI ([RFC3986], Section 5).
So a relative URI is now permitted. The effective request URI is the same as the request URI in most cases.
Relative URLs are valid.
There is a bug in RFC 2616. See http://greenbytes.de/tech/webdav/draft-ietf-httpbis-p2-semantics-17.html#rfc.section.9.5.