Fix timeout panic (grpc-ecosystem#2823)

* Handle nil contexts in Context methods

This will fix grpc-ecosystem#2822 for users who only update their runtime

* Avoid passing nil context to runtime.HTTPError

This will fix grpc-ecosystem#2822 for users who only update their generator

examples/internal/integration/integration_test.go

@@ -1574,6 +1574,31 @@ func TestTimeout(t *testing.T) {
  }
 }
 
+func TestInvalidTimeout(t *testing.T) {
+ if testing.Short() {
+ t.Skip()
+ return
+ }
+
+ apiURL := "http://localhost:8088/v2/example/timeout"
+ req, err := http.NewRequest("GET", apiURL, nil)
+ if err != nil {
+ t.Errorf(`http.NewRequest("GET", %q, nil) failed with %v; want success`, apiURL, err)
+ return
+ }
+ req.Header.Set("Grpc-Timeout", "INVALID")
+ resp, err := http.DefaultClient.Do(req)
+ if err != nil {
+ t.Errorf("http.DefaultClient.Do(%#v) failed with %v; want success", req, err)
+ return
+ }
+ defer resp.Body.Close()
+
+ if got, want := resp.StatusCode, http.StatusBadRequest; got != want {
+ t.Errorf("resp.StatusCode = %d; want %d", got, want)
+ }
+}
+
 func TestPostWithEmptyBody(t *testing.T) {
  if testing.Short() {
  t.Skip()
@@ -2359,8 +2384,8 @@ func testABEOptions(t *testing.T, port int) {
  client := &http.Client{}
  resp, err := client.Do(req)
  if err != nil {
- t.Fatal(err)
- }
+ t.Fatal(err)
+ }
  defer resp.Body.Close()
  if got, want := resp.StatusCode, http.StatusOK; got != want {
  t.Errorf("resp.StatusCode = %d; want %d", got, want)
@@ -2387,8 +2412,8 @@ func testABETrace(t *testing.T, port int) {
  client := &http.Client{}
  resp, err := client.Do(req)
  if err != nil {
- t.Fatal(err)
- }
+ t.Fatal(err)
+ }
  defer resp.Body.Close()
  buf, err := ioutil.ReadAll(resp.Body)
  if err != nil {