Go's default redirect behaviour seems to merge slashes in HTTP redirects. How can you override this behaviour?

gistfile1.go

package main

import (
    "testing"
    "net/http"
    "net/http/httptest"
)

func TestMergeSlashes(t *testing.T) {
    req, _ := http.NewRequest("GET", "http://foo.com/", nil)

    resp := httptest.NewRecorder()

    http.Redirect(resp, req, "/http://bar.com/", 302)

    if g, e := resp.Header().Get("Location"), "/http://bar.com/"; g != e {
        t.Errorf("Location header was %q; want %q", g, e)
    }
}