Fix for duplicate dates removal if combinePeriodsIfNecessary is set to true

modules/basics/src/main/java/com/opengamma/strata/basics/schedule/PeriodicSchedule.java

@@ -454,7 +454,7 @@ public Schedule createSchedule(ReferenceData refData, boolean combinePeriodsIfNe
         adj = new ArrayList<>(adj);
         unadj = new ArrayList<>(unadj);
         for (int i = 0; i < adj.size() - 1; i++) {
-          if (adj.get(i).equals(adj.get(i + 1))) {
+          while (i < adj.size() - 1 && adj.get(i).equals(adj.get(i + 1))) {
             adj.remove(i);
             unadj.remove(i);
           }

modules/basics/src/test/java/com/opengamma/strata/basics/schedule/PeriodicScheduleTest.java

@@ -13,6 +13,7 @@
 import static com.opengamma.strata.basics.date.HolidayCalendarIds.NO_HOLIDAYS;
 import static com.opengamma.strata.basics.date.HolidayCalendarIds.SAT_SUN;
 import static com.opengamma.strata.basics.schedule.Frequency.P12M;
+import static com.opengamma.strata.basics.schedule.Frequency.P1D;
 import static com.opengamma.strata.basics.schedule.Frequency.P1M;
 import static com.opengamma.strata.basics.schedule.Frequency.P1W;
 import static com.opengamma.strata.basics.schedule.Frequency.P2M;
@@ -73,6 +74,7 @@
 import com.opengamma.strata.basics.date.BusinessDayConvention;
 import com.opengamma.strata.basics.date.HolidayCalendar;
 import com.opengamma.strata.basics.date.HolidayCalendarId;
+import com.opengamma.strata.basics.date.HolidayCalendarIds;
 import com.opengamma.strata.basics.date.HolidayCalendars;
 
 /**
@@ -1208,6 +1210,49 @@ public HolidayCalendarId getId() {
     assertThat(schedule.getPeriod(2).getStartDate()).isEqualTo(date(2020, 10, 9));
   }
 
+  @Test
+  public void test_combinePeriodsWhenNecessary_1d_createSchedule_duplicate_exception() {
+    HolidayCalendarId id = SAT_SUN;
+    HolidayCalendar calendar = HolidayCalendars.SAT_SUN;
+
+    ReferenceData referenceData = ImmutableReferenceData.of(id, calendar);
+    BusinessDayAdjustment businessDayAdjustment = BusinessDayAdjustment.of(MODIFIED_FOLLOWING, id);
+    PeriodicSchedule defn = PeriodicSchedule.builder()
+            .startDate(date(2020, 9, 18))
+            .endDate(date(2020, 12, 18))
+            .frequency(P1D)
+            .businessDayAdjustment(businessDayAdjustment)
+            .stubConvention(SHORT_FINAL)
+            .rollConvention(null)
+            .build();
+
+    Schedule schedule = defn.createSchedule(referenceData, true);
+    assertThat(schedule.getPeriods()).hasSize(65);
+    assertThat(schedule.getPeriod(0).getStartDate()).isEqualTo(date(2020, 9, 18));
+    assertThat(schedule.getPeriod(0).getEndDate()).isEqualTo(date(2020, 9, 21));
+  }
+
+  @Test
+  public void test_combinePeriodsWhenNecessary_1d_createSchedule() {
+    HolidayCalendarId id = SAT_SUN;
+    HolidayCalendar calendar = HolidayCalendars.SAT_SUN;
+
+    ReferenceData referenceData = ImmutableReferenceData.of(id, calendar);
+    BusinessDayAdjustment businessDayAdjustment = BusinessDayAdjustment.of(MODIFIED_FOLLOWING, id);
+    PeriodicSchedule defn = PeriodicSchedule.builder()
+            .startDate(date(2020, 9, 18))
+            .endDate(date(2020, 12, 18))
+            .frequency(P1D)
+            .businessDayAdjustment(businessDayAdjustment)
+            .stubConvention(SHORT_FINAL)
+            .rollConvention(null)
+            .build();
+
+    assertThatExceptionOfType(ScheduleException.class)
+            .isThrownBy(() -> defn.createSchedule(referenceData, false))
+            .withMessageMatching(".*duplicate adjusted dates.*");
+  }
+
   @Test
   public void test_emptyWhenAdjusted_twoPeriods_createUnadjustedDates() {
     PeriodicSchedule defn = PeriodicSchedule.builder()

modules/product/src/main/java/com/opengamma/strata/product/bond/FixedCouponBond.java

@@ -161,10 +161,16 @@ private void validate() {
         "The ex-coupon period is measured from the payment date, thus the days must be non-positive");
   }
 
-  //-------------------------------------------------------------------------
+  /**
+   * Resolves fixed coupon bond using specified reference data.
+   * @param refData  the reference data to use when resolving
+   * @return the resolved instance
+   * @throws ReferenceDataNotFoundException if an identifier cannot be resolved in the reference data
+   * @throws RuntimeException if unable to resolve due to an invalid definition
+   */
   @Override
   public ResolvedFixedCouponBond resolve(ReferenceData refData) {
-    Schedule adjustedSchedule = accrualSchedule.createSchedule(refData);
+    Schedule adjustedSchedule = accrualSchedule.createSchedule(refData, true);
     Schedule unadjustedSchedule = adjustedSchedule.toUnadjusted();
     DateAdjuster exCouponPeriodAdjuster = exCouponPeriod.resolve(refData);