[Bug][SubscriptionBilling]: Customer cannot be changed on contract with closed subscription lines for 28.x (#7481)

<!-- Thank you for submitting a Pull Request. If you're new to
contributing to BCApps please read our pull request guideline below
* https://github.com/microsoft/BCApps/Contributing.md
-->
#### Summary <!-- Provide a general summary of your changes -->
This is a backport of the PR
#7070

#### Work Item(s) <!-- Add the issue number here after the #. The issue
needs to be open and approved. Submitting PRs with no linked issues or
unapproved issues is highly discouraged. -->
Fixes ##6970

[AB#631933](https://dynamicssmb2.visualstudio.com/1fcb79e7-ab07-432a-a3c6-6cf5a88ba4a5/_workitems/edit/631933)

Author: miljance

src/Apps/W1/Subscription Billing/App/Service Commitments/Tables/SubscriptionLine.Table.al

@@ -882,7 +882,7 @@ table 8059 "Subscription Line"
         OnAfterCalculateServiceAmount(Rec, CalledByFieldNo);
     end;
 
-    local procedure SetUpdateRequiredOnBillingLines()
+    internal procedure SetUpdateRequiredOnBillingLines()
     var
         BillingLine: Record "Billing Line";
     begin
@@ -1347,7 +1347,9 @@ table 8059 "Subscription Line"
             repeat
 #pragma warning disable AA0214
                 ServiceCommitment.ResetAmountsAndCurrencyFromLCY();
-                ServiceCommitment.Modify(true);
+                ServiceCommitment.SetUpdateRequiredOnBillingLines();
+                ServiceCommitment.ArchiveServiceCommitment();
+                ServiceCommitment.Modify(false);
 #pragma warning restore AA0214
             until ServiceCommitment.Next() = 0;
     end;
@@ -1371,7 +1373,9 @@ table 8059 "Subscription Line"
                     CurrencyCode := ServiceCommitment."Currency Code";
                 ServiceCommitment.SetCurrencyData(CurrencyFactor, CurrencyFactorDate, CurrencyCode);
                 ServiceCommitment.RecalculateAmountsFromCurrencyData();
-                ServiceCommitment.Modify(true);
+                ServiceCommitment.SetUpdateRequiredOnBillingLines();
+                ServiceCommitment.ArchiveServiceCommitment();
+                ServiceCommitment.Modify(false);
             until ServiceCommitment.Next() = 0;
     end;
 

src/Apps/W1/Subscription Billing/App/Service Objects/Tables/SubscriptionHeader.Table.al

@@ -2035,9 +2035,10 @@ table 8057 "Subscription Header"
                     if FieldCaption(Quantity) <> ChangedFieldName then
                         ServiceCommitment.CalculateCalculationBaseAmount();
                     ServiceCommitment.Validate("Calculation Base Amount");
-                    if SkipArchiving then
-                        ServiceCommitment.SetSkipArchiving(true);
-                    ServiceCommitment.Modify(true);
+                    ServiceCommitment.SetUpdateRequiredOnBillingLines();
+                    if not SkipArchiving then
+                        ServiceCommitment.ArchiveServiceCommitment();
+                    ServiceCommitment.Modify(false);
                 until ServiceCommitment.Next() = 0;
         end else
             if (not Confirmed) and (FieldCaption("Variant Code") = ChangedFieldName) then

src/Apps/W1/Subscription Billing/Test/Customer Contracts/ContractsTest.Codeunit.al

@@ -2053,6 +2053,45 @@ codeunit 148155 "Contracts Test"
         Assert.AreEqual(TestDesc, ServiceCommitment.Description, StrSubstNo(SubscLineDescErr, TestDesc));
     end;
 
+    [Test]
+    [HandlerFunctions('ExchangeRateSelectionModalPageHandler,MessageHandler')]
+    procedure ChangeSellToCustomerOnContractWithClosedSubscriptionLines()
+    var
+        Customer: Record Customer;
+        CustomerContract: Record "Customer Subscription Contract";
+        CustomerContractLine: Record "Cust. Sub. Contract Line";
+        NewCustomer: Record Customer;
+        ServiceCommitment: Record "Subscription Line";
+        ServiceObject: Record "Subscription Header";
+    begin
+        // [SCENARIO] Changing the Sell-to Customer on a contract that has closed subscription lines should succeed without error.
+        Initialize();
+
+        // [GIVEN] A customer contract with a service commitment linked to a contract line.
+        SetupServiceObjectForNewItemWithServiceCommitment(Customer, ServiceObject, false, false);
+        ContractTestLibrary.CreateCustomerContractAndCreateContractLinesForItems(CustomerContract, ServiceObject, Customer."No.");
+
+        // [GIVEN] The contract line and its subscription line are both marked as closed (as done by UpdateServiceCommitmentAndCloseCustomerContractLine).
+        CustomerContractLine.SetRange("Subscription Contract No.", CustomerContract."No.");
+        CustomerContractLine.SetRange("Contract Line Type", Enum::"Contract Line Type"::Item);
+        CustomerContractLine.FindFirst();
+        CustomerContractLine.GetServiceCommitment(ServiceCommitment);
+        ServiceCommitment.Closed := true;
+        ServiceCommitment.Modify(false);
+        CustomerContractLine.Closed := true;
+        CustomerContractLine.Modify(false);
+
+        // [GIVEN] A second customer to change the contract to.
+        ContractTestLibrary.CreateCustomerInLCY(NewCustomer);
+
+        // [WHEN] Changing the Sell-to Customer - should not throw an error even though closed subscription lines exist.
+        CustomerContract.SetHideValidationDialog(true);
+        CustomerContract.Validate("Sell-to Customer No.", NewCustomer."No.");
+
+        // [THEN] The customer is changed successfully.
+        CustomerContract.TestField("Sell-to Customer No.", NewCustomer."No.");
+    end;
+
     #endregion Tests
 
     #region Procedures