Fix a bug in pod listing introduced in a recent refactor.

Add a test to catch a regression in the future.

pkg/registry/etcd_registry.go

@@ -78,6 +78,7 @@ func (registry *EtcdRegistry) ListPods(query labels.Query) ([]api.Pod, error) {
 		}
 		for _, pod := range machinePods {
 			if query.Matches(labels.Set(pod.Labels)) {
+				pod.CurrentState.Host = machine
 				pods = append(pods, pod)
 			}
 		}

pkg/registry/etcd_registry_test.go

@@ -354,6 +354,10 @@ func TestEtcdListPods(t *testing.T) {
 	if len(pods) != 2 || pods[0].ID != "foo" || pods[1].ID != "bar" {
 		t.Errorf("Unexpected pod list: %#v", pods)
 	}
+	if pods[0].CurrentState.Host != "machine" ||
+		pods[1].CurrentState.Host != "machine" {
+		t.Errorf("Failed to populate host name.")
+	}
 }
 
 func TestEtcdListControllersNotFound(t *testing.T) {