killbill-memoizeit

diff --git a/invoice/src/main/java/org/killbill/billing/invoice/api/user/DefaultInvoiceUserApi.java b/invoice/src/main/java/org/killbill/billing/invoice/api/user/DefaultInvoiceUserApi.java
index 23ce2f9..a6d48eb 100644
--- a/invoice/src/main/java/org/killbill/billing/invoice/api/user/DefaultInvoiceUserApi.java
+++ b/invoice/src/main/java/org/killbill/billing/invoice/api/user/DefaultInvoiceUserApi.java
@@ -207,7 +207,7 @@ public class DefaultInvoiceUserApi implements InvoiceUserApi {
         return getInvoiceInternal(invoiceId, context);
     }
 
-    private DefaultInvoice getInvoiceInternal(final UUID invoiceId, final TenantContext context) throws InvoiceApiException  {
+    private DefaultInvoice getInvoiceInternal(final UUID invoiceId, final TenantContext context) throws InvoiceApiException {
         final InternalTenantContext internalTenantContext = internalCallContextFactory.createInternalTenantContext(invoiceId, ObjectType.INVOICE, context);
         return new DefaultInvoice(dao.getById(invoiceId, internalTenantContext), getCatalogSafelyForPrettyNames(internalTenantContext));
     }
@@ -281,7 +281,7 @@ public class DefaultInvoiceUserApi implements InvoiceUserApi {
     @Override
     public List<InvoiceItem> insertExternalCharges(final UUID accountId, final LocalDate effectiveDate, final Iterable<InvoiceItem> charges, final boolean autoCommit, final CallContext context) throws InvoiceApiException {
         for (final InvoiceItem charge : charges) {
-            if (charge.getAmount() == null || charge.getAmount().compareTo(BigDecimal.ZERO) <= 0) {
+            if (charge.getAmount() == null || charge.getAmount().compareTo(BigDecimal.ZERO) < 0) {
                 throw new InvoiceApiException(ErrorCode.EXTERNAL_CHARGE_AMOUNT_INVALID, charge.getAmount());
             }
         }
@@ -643,7 +643,7 @@ public class DefaultInvoiceUserApi implements InvoiceUserApi {
     private void canInvoiceBeVoided(final Invoice invoice) throws InvoiceApiException {
         final List<InvoicePayment> invoicePayments = invoice.getPayments();
         final BigDecimal amountPaid = InvoiceCalculatorUtils.computeInvoiceAmountPaid(invoice.getCurrency(), invoicePayments)
-                .add(InvoiceCalculatorUtils.computeInvoiceAmountRefunded(invoice.getCurrency(), invoicePayments));
+                                                            .add(InvoiceCalculatorUtils.computeInvoiceAmountRefunded(invoice.getCurrency(), invoicePayments));
 
         if (amountPaid.compareTo(BigDecimal.ZERO) != 0) {
             throw new InvoiceApiException(ErrorCode.CAN_NOT_VOID_INVOICE_THAT_IS_PAID, invoice.getId().toString());

diff --git a/jaxrs/src/main/java/org/killbill/billing/jaxrs/resources/InvoiceResource.java b/jaxrs/src/main/java/org/killbill/billing/jaxrs/resources/InvoiceResource.java
index 7ca3659..029b662 100644
--- a/jaxrs/src/main/java/org/killbill/billing/jaxrs/resources/InvoiceResource.java
+++ b/jaxrs/src/main/java/org/killbill/billing/jaxrs/resources/InvoiceResource.java
@@ -558,7 +558,7 @@ public class InvoiceResource extends JaxRsResourceBase {
                     } else {
                         return new InvoiceItemJson(null,
                                                    input.getInvoiceId(),
-                                                   null,
+                                                   input.getLinkedInvoiceItemId(),
                                                    input.getAccountId(),
                                                    input.getChildAccountId(),
                                                    input.getBundleId(),