checkPodsScheduledForDeployment: Add nil check

checkPodsScheduledForDeployment takes a pointer to a deployment, which
should never be nil, so return an error indicating that there is a bug
if the deployment is somehow nil.

* pkg/operator/controller/ingress/status.go
(checkPodsScheduledForDeployment): Check whether deployment is nil and
return an error if it is.
* pkg/operator/controller/ingress/status_test.go
(Test_checkPodsScheduledForDeployment): Add a "nil deployment" test case.

pkg/operator/controller/ingress/status.go

@@ -208,6 +208,9 @@ func computeAllowedSourceRanges(service *corev1.Service) []operatorv1.CIDR {
 // PodsScheduled=True.  This function returns an error value indicating the
 // result of that check.
 func checkPodsScheduledForDeployment(deployment *appsv1.Deployment, pods []corev1.Pod) error {
+	if deployment == nil {
+		return errors.New("System error detected: deployment was nil.  Please report this issue to Red Hat: https://issues.redhat.com/secure/CreateIssueDetails!init.jspa?pid=12332330&issuetype=1&components=12367900&priority=10300&customfield_12316142=26752")
+	}
 	selector, err := metav1.LabelSelectorAsSelector(deployment.Spec.Selector)
 	if err != nil || selector.Empty() {
 		return errors.New("Deployment has an invalid label selector.")

pkg/operator/controller/ingress/status_test.go

@@ -208,6 +208,12 @@ func Test_checkPodsScheduledForDeployment(t *testing.T) {
 		pods        []corev1.Pod
 		expectError bool
 	}{
+		{
+			name:        "nil deployment",
+			deployment:  nil,
+			pods:        []corev1.Pod{scheduledPod},
+			expectError: true,
+		},
 		{
 			name:        "no pods",
 			deployment:  deployment,