Should http/cgi default to a 3xx status if the child returns a "Location"
header but no explicit status?

http://www.ietf.org/rfc/rfc3875

Also, might want to support server-fetched redirects if the caller opts-in by defining a
FetchingRedirectClient *http.Client in their handler struct:


6.3.2.  Location

   The Location header field is used to specify to the server that the
   script is returning a reference to a document rather than an actual
   document (see sections 6.2.3 and 6.2.4).  It is either an absolute
   URI (optionally with a fragment identifier), indicating that the
   client is to fetch the referenced document, or a local URI path
   (optionally with a query string), indicating that the server is to
   fetch the referenced document and return it to the client as the
   response.

      Location        = local-Location | client-Location
      client-Location = "Location:" fragment-URI NL
      local-Location  = "Location:" local-pathquery NL
      fragment-URI    = absoluteURI [ "#" fragment ]
      fragment        = *uric
      local-pathquery = abs-path [ "?" query-string ]
      abs-path        = "/" path-segments
      path-segments   = segment *( "/" segment )
      segment         = *pchar
      pchar           = unreserved | escaped | extra
      extra           = ":" | "@" | "&" | "=" | "+" | "$" | ","

   The syntax of an absoluteURI is incorporated into this document from
   that specified in RFC 2396 [2] and RFC 2732 [7].  A valid absoluteURI
   always starts with the name of scheme followed by ":"; scheme names
   start with a letter and continue with alphanumerics, "+", "-" or ".".
   The local URI path and query must be an absolute path, and not a
   relative path or NULL, and hence must start with a "/".

   Note that any message-body attached to the request (such as for a
   POST request) may not be available to the resource that is the target
   of the redirect.