agent: Fixing bug in dns service filtering

command/agent/dns.go

@@ -384,6 +384,7 @@ func (d *DNSServer) filterServiceNodes(nodes structs.CheckServiceNodes) structs.
 					node.Node.Node, check.CheckID, check.Name, node.Service.Service)
 				nodes[i], nodes[n-1] = nodes[n-1], structs.CheckServiceNode{}
 				n--
+				i--
 			}
 		}
 	}

command/agent/dns_test.go

@@ -332,7 +332,7 @@ func TestDNS_ServiceLookup_FilterCritical(t *testing.T) {
 	// Wait for leader
 	time.Sleep(100 * time.Millisecond)
 
-	// Register node
+	// Register nodes
 	args := &structs.RegisterRequest{
 		Datacenter: "dc1",
 		Node:       "foo",
@@ -353,6 +353,25 @@ func TestDNS_ServiceLookup_FilterCritical(t *testing.T) {
 		t.Fatalf("err: %v", err)
 	}
 
+	args2 := &structs.RegisterRequest{
+		Datacenter: "dc1",
+		Node:       "bar",
+		Address:    "127.0.0.2",
+		Service: &structs.NodeService{
+			Service: "db",
+			Tag:     "master",
+			Port:    12345,
+		},
+		Check: &structs.HealthCheck{
+			CheckID: "serf",
+			Name:    "serf",
+			Status:  structs.HealthCritical,
+		},
+	}
+	if err := srv.agent.RPC("Catalog.Register", args2, &out); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
 	m := new(dns.Msg)
 	m.SetQuestion("db.service.consul.", dns.TypeANY)