Allow domain transfers with 0 period and in auto-renew grace period

Normally, if a domain is in the auto-renew grace period, a transfer will cancel the auto-renew billing event. In the event of a transfer with no change to registration end date, the auto-renew billing event should not be cancelled and the gaining registrar should not be charged for the transfer.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=170576726

java/google/registry/flows/domain/DomainTransferApproveFlow.java

@@ -138,8 +138,15 @@ public final class DomainTransferApproveFlow implements TransactionalFlow {
     int extraYears = transferData.getTransferPeriod().getValue();
     if (autorenewGrace != null) {
       extraYears = 0;
-      ofy().save().entity(
-          BillingEvent.Cancellation.forGracePeriod(autorenewGrace, historyEntry, targetId));
+      // During a normal transfer, if the domain is in the auto-renew grace period, the auto-renew
+      // billing event is cancelled and the gaining registrar is charged for the one year renewal.
+      // But, if the superuser extension is used to request a transfer without an additional year
+      // then the gaining registrar is not charged for the one year renewal and the losing registrar
+      // still needs to be charged for the auto-renew.
+      if (billingEvent.isPresent()) {
+        ofy().save().entity(
+            BillingEvent.Cancellation.forGracePeriod(autorenewGrace, historyEntry, targetId));
+      }
     }
     // Close the old autorenew event and poll message at the transfer time (aka now). This may end
     // up deleting the poll message.

java/google/registry/flows/domain/DomainTransferRequestFlow.java

@@ -46,7 +46,6 @@ import google.registry.flows.annotations.ReportingSpec;
 import google.registry.flows.exceptions.AlreadyPendingTransferException;
 import google.registry.flows.exceptions.InvalidTransferPeriodValueException;
 import google.registry.flows.exceptions.ObjectAlreadySponsoredException;
-import google.registry.flows.exceptions.SuperuserExtensionAndAutorenewGracePeriodException;
 import google.registry.flows.exceptions.TransferPeriodMustBeOneYearException;
 import google.registry.flows.exceptions.TransferPeriodZeroAndFeeTransferExtensionException;
 import google.registry.model.domain.DomainCommand.Transfer;
@@ -99,7 +98,6 @@ import org.joda.time.DateTime;
  * @error {@link google.registry.flows.exceptions.MissingTransferRequestAuthInfoException}
  * @error {@link google.registry.flows.exceptions.ObjectAlreadySponsoredException}
  * @error {@link google.registry.flows.exceptions.ResourceStatusProhibitsOperationException}
- * @error {@link google.registry.flows.exceptions.SuperuserExtensionAndAutorenewGracePeriodException}
  * @error {@link google.registry.flows.exceptions.TransferPeriodMustBeOneYearException}
  * @error {@link InvalidTransferPeriodValueException}
  * @error {@link google.registry.flows.exceptions.TransferPeriodZeroAndFeeTransferExtensionException}
@@ -184,10 +182,6 @@ public final class DomainTransferRequestFlow implements TransactionalFlow {
     DomainResource domainAtTransferTime =
         existingDomain.cloneProjectedAtTime(automaticTransferTime);
     if (!domainAtTransferTime.getGracePeriodsOfType(GracePeriodStatus.AUTO_RENEW).isEmpty()) {
-      if (superuserExtension != null) {
-        // We don't allow the superuser extension for domains in the auto renew grace period
-        throw new SuperuserExtensionAndAutorenewGracePeriodException();
-      }
       extraYears = 0;
     }
     // The new expiration time if there is a server approval.

java/google/registry/flows/domain/DomainTransferUtils.java

@@ -119,7 +119,7 @@ public final class DomainTransferUtils {
     return builder
         .addAll(
             createOptionalAutorenewCancellation(
-                    automaticTransferTime, historyEntry, targetId, existingDomain)
+                    automaticTransferTime, historyEntry, targetId, existingDomain, transferCost)
                 .asSet())
         .add(
             createGainingClientAutorenewEvent(
@@ -229,7 +229,9 @@ public final class DomainTransferUtils {
    * expiration time. Since the gaining registrar will still be billed for the transfer's 1-year
    * renewal, we must issue a cancellation for the autorenew, so that the losing registrar will not
    * be charged (essentially, the gaining registrar takes on the cost of the year of registration
-   * that the autorenew just added).
+   * that the autorenew just added). But, if the superuser extension is used to request a transfer
+   * without an additional year then the gaining registrar is not charged for the one year renewal
+   * and the losing registrar still needs to be charged for the auto-renew.
    *
    * <p>For details on the policy justification, see b/19430703#comment17 and <a
    * href="https://www.icann.org/news/advisory-2002-06-06-en">this ICANN advisory</a>.
@@ -238,13 +240,14 @@ public final class DomainTransferUtils {
       DateTime automaticTransferTime,
       HistoryEntry historyEntry,
       String targetId,
-      DomainResource existingDomain) {
+      DomainResource existingDomain,
+      Optional<Money> transferCost) {
     DomainResource domainAtTransferTime =
         existingDomain.cloneProjectedAtTime(automaticTransferTime);
     GracePeriod autorenewGracePeriod =
         getOnlyElement(
             domainAtTransferTime.getGracePeriodsOfType(GracePeriodStatus.AUTO_RENEW), null);
-    if (autorenewGracePeriod != null) {
+    if (autorenewGracePeriod != null && transferCost.isPresent()) {
       return Optional.of(
           BillingEvent.Cancellation.forGracePeriod(autorenewGracePeriod, historyEntry, targetId)
               .asBuilder()

java/google/registry/flows/exceptions/SuperuserExtensionAndAutorenewGracePeriodException.java

@@ -1,25 +0,0 @@
-// Copyright 2017 The Nomulus Authors. All Rights Reserved.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package google.registry.flows.exceptions;
-
-import google.registry.flows.EppException.StatusProhibitsOperationException;
-
-/** Superuser extensions cannot be used during autorenew grace periods. */
-public class SuperuserExtensionAndAutorenewGracePeriodException extends
-    StatusProhibitsOperationException {
-  public SuperuserExtensionAndAutorenewGracePeriodException() {
-    super("Superuser extensions cannot be used during autorenew grace periods.");
-  }
-}