allow space-delimited application-provided user agent

test/end2end_test.go

@@ -62,7 +62,7 @@ var (
 		"key1": "value1",
 		"key2": "value2",
 	}
-	testAppUA = "myApp/1.0"
+	testAppUA = "myApp1/1.0 myApp2/0.9"
 )
 
 type testServer struct {

transport/http_util.go

@@ -164,13 +164,13 @@ func newHPACKDecoder() *hpackDecoder {
 		default:
 			if !isReservedHeader(f.Name) {
 				if f.Name == "user-agent" {
-					str := strings.Split(f.Value, " ")
-					if len(str) <= 1 {
+					ind := strings.LastIndex(f.Value, " ")
+					if ind == -1 {
 						// There is no application user agent string being set.
 						return
 					}
 					// Extract the application user agent string.
-					f.Value = str[0]
+					f.Value = f.Value[:ind]
 				}
 				if d.state.mdata == nil {
 					d.state.mdata = make(map[string]string)