gzip strips Accept-Encoding header after using it

middleware/fastcgi/fastcgi.go

@@ -196,11 +196,7 @@ func (h Handler) buildEnv(r *http.Request, rule Rule) (map[string]string, error)
 	for field, val := range r.Header {
 		header := strings.ToUpper(field)
 		header = headerNameReplacer.Replace(header)
-		// We don't want to pass the encoding header to prevent the fastcgi server from gzipping
-		// TODO: is there a better way.
-		if header != "ACCEPT_ENCODING" {
-			env["HTTP_"+header] = strings.Join(val, ", ")
-		}
+		env["HTTP_"+header] = strings.Join(val, ", ")
 	}
 
 	return env, nil

middleware/gzip/gzip.go

@@ -33,6 +33,9 @@ func (g Gzip) ServeHTTP(w http.ResponseWriter, r *http.Request) (int, error) {
 		return g.Next.ServeHTTP(w, r)
 	}
 
+	// Delete this header so gzipping isn't repeated later in the chain
+	r.Header.Del("Accept-Encoding")
+
 	w.Header().Set("Content-Encoding", "gzip")
 	gzipWriter := gzip.NewWriter(w)
 	defer gzipWriter.Close()