net/http/httputil: preserve query params in reverse proxy

Fixes #2853

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/5642056

diff --git a/src/pkg/net/http/httputil/reverseproxy.go b/src/pkg/net/http/httputil/reverseproxy.go
index 1072e2e342604bb47fa32812f45569f73821cab1..9c4bd6e09a5c81aa09c9ea264b597b19ab21a2d0 100644 (file)
--- a/src/pkg/net/http/httputil/reverseproxy.go
+++ b/src/pkg/net/http/httputil/reverseproxy.go
@@ -55,11 +55,16 @@ func singleJoiningSlash(a, b string) string {
 // target's path is "/base" and the incoming request was for "/dir",
 // the target request will be for /base/dir.
 func NewSingleHostReverseProxy(target *url.URL) *ReverseProxy {
+       targetQuery := target.RawQuery
        director := func(req *http.Request) {
                req.URL.Scheme = target.Scheme
                req.URL.Host = target.Host
                req.URL.Path = singleJoiningSlash(target.Path, req.URL.Path)
-               req.URL.RawQuery = target.RawQuery
+               if targetQuery == "" || req.URL.RawQuery == "" {
+                       req.URL.RawQuery = targetQuery + req.URL.RawQuery
+               } else {
+                       req.URL.RawQuery = targetQuery + "&" + req.URL.RawQuery
+               }
        }
        return &ReverseProxy{Director: director}
 }

diff --git a/src/pkg/net/http/httputil/reverseproxy_test.go b/src/pkg/net/http/httputil/reverseproxy_test.go
index 655784b30d5f195d7603ffde0b0dac3247df2027..28e9c90ad36cdac93a4550a4384b1a481edbf1b6 100644 (file)
--- a/src/pkg/net/http/httputil/reverseproxy_test.go
+++ b/src/pkg/net/http/httputil/reverseproxy_test.go
@@ -69,3 +69,41 @@ func TestReverseProxy(t *testing.T) {
                t.Errorf("got body %q; expected %q", g, e)
        }
 }
+
+var proxyQueryTests = []struct {
+       baseSuffix string // suffix to add to backend URL
+       reqSuffix  string // suffix to add to frontend's request URL
+       want       string // what backend should see for final request URL (without ?)
+}{
+       {"", "", ""},
+       {"?sta=tic", "?us=er", "sta=tic&us=er"},
+       {"", "?us=er", "us=er"},
+       {"?sta=tic", "", "sta=tic"},
+}
+
+func TestReverseProxyQuery(t *testing.T) {
+       backend := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+               w.Header().Set("X-Got-Query", r.URL.RawQuery)
+               w.Write([]byte("hi"))
+       }))
+       defer backend.Close()
+
+       for i, tt := range proxyQueryTests {
+               backendURL, err := url.Parse(backend.URL + tt.baseSuffix)
+               if err != nil {
+                       t.Fatal(err)
+               }
+               frontend := httptest.NewServer(NewSingleHostReverseProxy(backendURL))
+               req, _ := http.NewRequest("GET", frontend.URL+tt.reqSuffix, nil)
+               req.Close = true
+               res, err := http.DefaultClient.Do(req)
+               if err != nil {
+                       t.Fatalf("%d. Get: %v", i, err)
+               }
+               if g, e := res.Header.Get("X-Got-Query"), tt.want; g != e {
+                       t.Errorf("%d. got query %q; expected %q", i, g, e)
+               }
+               res.Body.Close()
+               frontend.Close()
+       }
+}