killbill-memoizeit

diff --git a/invoice/src/main/java/com/ning/billing/invoice/generator/InvoiceDateUtils.java b/invoice/src/main/java/com/ning/billing/invoice/generator/InvoiceDateUtils.java
index f35d53e..e9f14b9 100644
--- a/invoice/src/main/java/com/ning/billing/invoice/generator/InvoiceDateUtils.java
+++ b/invoice/src/main/java/com/ning/billing/invoice/generator/InvoiceDateUtils.java
@@ -69,10 +69,15 @@ public class InvoiceDateUtils {
         if (proposedDate.dayOfMonth().get() < billingCycleDay) {
             final int lastDayOfTheMonth = proposedDate.dayOfMonth().getMaximumValue();
             if (lastDayOfTheMonth < billingCycleDay) {
-                return new LocalDate(proposedDate.getYear(), proposedDate.getMonthOfYear(), lastDayOfTheMonth);
+                proposedDate = new LocalDate(proposedDate.getYear(), proposedDate.getMonthOfYear(), lastDayOfTheMonth);
             } else {
-                return new LocalDate(proposedDate.getYear(), proposedDate.getMonthOfYear(), billingCycleDay);
+                proposedDate = new LocalDate(proposedDate.getYear(), proposedDate.getMonthOfYear(), billingCycleDay);
             }
+        }
+
+        if (proposedDate.isBefore(previousBillCycleDate)) {
+            // Make sure not to go too far in the past
+            return previousBillCycleDate;
         } else {
             return proposedDate;
         }

diff --git a/invoice/src/main/java/com/ning/billing/invoice/model/InAdvanceBillingMode.java b/invoice/src/main/java/com/ning/billing/invoice/model/InAdvanceBillingMode.java
index fed28f8..07e385b 100644
--- a/invoice/src/main/java/com/ning/billing/invoice/model/InAdvanceBillingMode.java
+++ b/invoice/src/main/java/com/ning/billing/invoice/model/InAdvanceBillingMode.java
@@ -74,6 +74,7 @@ public class InAdvanceBillingMode implements BillingMode {
         } else {
             effectiveEndDate = calculateEffectiveEndDate(firstBillingCycleDate, targetDate, billingPeriod);
         }
+
         final LocalDate lastBillingCycleDate = calculateLastBillingCycleDateBefore(effectiveEndDate, firstBillingCycleDate, billingCycleDayLocal, billingPeriod);
         final int numberOfWholeBillingPeriods = calculateNumberOfWholeBillingPeriods(firstBillingCycleDate, lastBillingCycleDate, billingPeriod);
         final int numberOfMonthsPerBillingPeriod = billingPeriod.getNumberOfMonths();

diff --git a/invoice/src/test/java/com/ning/billing/invoice/generator/TestInvoiceDateUtils.java b/invoice/src/test/java/com/ning/billing/invoice/generator/TestInvoiceDateUtils.java
index a496d14..5d419a0 100644
--- a/invoice/src/test/java/com/ning/billing/invoice/generator/TestInvoiceDateUtils.java
+++ b/invoice/src/test/java/com/ning/billing/invoice/generator/TestInvoiceDateUtils.java
@@ -28,13 +28,14 @@ import com.ning.billing.catalog.api.BillingPeriod;
 public class TestInvoiceDateUtils {
 
     @Test(groups = "fast")
-    public void testLastBCDShouldBeInThePast() throws Exception {
+    public void testLastBCDShouldNotBeBeforePreviousBCD() throws Exception {
         final LocalDate from = new LocalDate("2012-07-16");
         final LocalDate previousBCD = new LocalDate("2012-08-15");
         final int bcdLocal = 15;
         final LocalDate lastBCD = InvoiceDateUtils.calculateLastBillingCycleDateBefore(from, previousBCD, bcdLocal, BillingPeriod.MONTHLY);
-        Assert.assertEquals(lastBCD, new LocalDate("2012-07-15"));
+        Assert.assertEquals(lastBCD, new LocalDate("2012-08-15"));
     }
+
     @Test(groups = "fast")
     public void testNextBCDShouldNotBeInThePast() throws Exception {
         final LocalDate from = new LocalDate("2012-07-16");