Fix panic on multiple non-matching canary

test/e2e/annotations/canary.go

@@ -758,4 +758,28 @@ var _ = framework.IngressNginxDescribe("Annotations - canary", func() {
 			})
 		})
 	})
+
+	Context("Single canary Ingress with multiple paths to same backend", func() {
+		It("should work", func() {
+			host := "foo"
+			canaryIngName := fmt.Sprintf("%v-canary", host)
+			annotations := map[string]string{
+				"nginx.ingress.kubernetes.io/canary":           "true",
+				"nginx.ingress.kubernetes.io/canary-by-header": "CanaryByHeader",
+			}
+
+			paths := []string{"/foo", "/bar"}
+
+			ing := framework.NewSingleIngressWithMultiplePaths(canaryIngName, paths, host, f.Namespace, "httpy-svc-canary", 80, &annotations)
+			f.EnsureIngress(ing)
+
+			ing = framework.NewSingleIngress(host, "/", host, f.Namespace, "http-svc", 80, nil)
+			f.EnsureIngress(ing)
+
+			f.WaitForNginxServer(host,
+				func(server string) bool {
+					return Expect(server).Should(ContainSubstring("server_name foo"))
+				})
+		})
+	})
 })