Merge pull request 'fix query param struct filling' (#167) from matchesfix into v3

Reviewed-on: #167

handler.go

@@ -349,11 +349,18 @@ func (h *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		md[k] = strings.Join(v, ", ")
 	}
 	md["RemoteAddr"] = r.RemoteAddr
+	if r.TLS != nil {
+		md["Scheme"] = "https"
+	} else {
+		md["Scheme"] = "http"
+	}
 	md["Method"] = r.Method
 	md["URL"] = r.URL.String()
 	md["Proto"] = r.Proto
 	md["ContentLength"] = fmt.Sprintf("%d", r.ContentLength)
-	md["TransferEncoding"] = strings.Join(r.TransferEncoding, ",")
+	if len(r.TransferEncoding) > 0 {
+		md["TransferEncoding"] = strings.Join(r.TransferEncoding, ",")
+	}
 	md["Host"] = r.Host
 	md["RequestURI"] = r.RequestURI
 	ctx = metadata.NewIncomingContext(ctx, md)
@@ -480,10 +487,12 @@ func (h *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		}
 	}
 
-	matches = rflutil.FlattenMap(matches)
-	if err = rflutil.Merge(argv.Interface(), matches, rflutil.SliceAppend(true), rflutil.Tags([]string{"protobuf", "json"})); err != nil {
-		h.errorHandler(ctx, handler, w, r, err, http.StatusBadRequest)
-		return
+	if len(matches) > 0 {
+		matches = rflutil.FlattenMap(matches)
+		if err = rflutil.Merge(argv.Interface(), matches, rflutil.SliceAppend(true), rflutil.Tags([]string{"protobuf", "json"})); err != nil {
+			h.errorHandler(ctx, handler, w, r, err, http.StatusBadRequest)
+			return
+		}
 	}
 
 	hr := &rpcRequest{