Fixed issue with getting occurrences at the border of years

v2/Ical.Net.nuspec

@@ -2,7 +2,7 @@
 <package xmlns="http://schemas.microsoft.com/packaging/2010/07/nuspec.xsd">
     <metadata>
         <id>Ical.Net</id>
-        <version>2.2.32</version>
+        <version>2.2.33</version>
         <title>Ical.Net</title>
         <authors>Rian Stockbower, Douglas Day, M. David Peterson</authors>
         <owners>Rian Stockbower</owners>

v2/ical.NET.UnitTests/GetOccurrenceTests.cs

@@ -1,7 +1,10 @@
 using System;
+using System.Collections.Generic;
 using System.IO;
 using System.Linq;
 using Ical.Net.DataTypes;
+using Ical.Net.Interfaces.DataTypes;
+using Ical.Net.Utility;
 using NUnit.Framework;
 
 namespace Ical.Net.UnitTests
@@ -51,6 +54,44 @@ public void WrongDurationTest()
             Assert.AreEqual(secondEndCopy, secondOccurrence.Period.EndTime);
         }
 
+        [Test]
+        public void SkippedOccurrenceOnWeeklyPattern()
+        {
+            const int evaluationsCount = 1000;
+            var eventStart = new CalDateTime(new DateTime(2016, 1, 1, 10, 0, 0, DateTimeKind.Utc));
+            var eventEnd = new CalDateTime(new DateTime(2016, 1, 1, 11, 0, 0, DateTimeKind.Utc));
+            var vEvent = new Event
+            {
+                DtStart = eventStart,
+                DtEnd = eventEnd,
+            };
+
+            var pattern = new RecurrencePattern
+            {
+                Frequency = FrequencyType.Weekly,
+                ByDay = new List<IWeekDay> { new WeekDay(DayOfWeek.Friday) }
+
+            };
+            vEvent.RecurrenceRules.Add(pattern);
+            var calendar = new Calendar();
+            calendar.Events.Add(vEvent);
+
+            var intervalStart = eventStart;
+            var intervalEnd = intervalStart.AddDays(7 * evaluationsCount);
+
+            var occurrences = RecurrenceUtil.GetOccurrences(vEvent, intervalStart, intervalEnd, false)
+                .Select(o => o.Period.StartTime)
+                .OrderBy(dt => dt)
+                .ToList();
+            Assert.AreEqual(evaluationsCount, occurrences.Count);
+            for (DateTime currentOccurrence = intervalStart.AsUtc;
+                currentOccurrence.CompareTo(intervalEnd.AsUtc) < 0; currentOccurrence = currentOccurrence.AddDays(7))
+            {
+                Assert.IsTrue(occurrences.Contains(new CalDateTime(currentOccurrence)),
+                    string.Format("Collection does not contain {0}, but it is a {1}", currentOccurrence, currentOccurrence.DayOfWeek));
+            }
+        }
+
         [Test]
         public void EnumerationChangedException()
         {

v2/ical.NET/Evaluation/RecurrencePatternEvaluator.cs

@@ -679,10 +679,22 @@ private List<DateTime> GetAbsWeekDays(DateTime date, IWeekDay weekDay, IRecurren
                     date = date.AddDays(1);
                 }
 
-                while (Calendar.GetWeekOfYear(date, CalendarWeekRule.FirstFourDayWeek, pattern.FirstDayOfWeek) == weekNo)
+                var nextWeekNo = Calendar.GetWeekOfYear(date, CalendarWeekRule.FirstFourDayWeek,
+                    pattern.FirstDayOfWeek);
+
+                var currentWeekNo = Calendar.GetWeekOfYear(date, CalendarWeekRule.FirstFourDayWeek,
+                    pattern.FirstDayOfWeek);
+                while (currentWeekNo == weekNo ||
+                       //When we manage weekly recurring pattern and we have boundary case:
+                       //Weekdays: 31.12, 01.01, 02.01, 03.01, 04.01, 05.01, 06.01
+                       //31.12 - It's a 53th week number, but all another are 1st week number.
+                       //So, we should add exception rule for this situation(only for weekly events).
+                       (nextWeekNo < weekNo && currentWeekNo == nextWeekNo && pattern.Frequency == FrequencyType.Weekly))
                 {
                     days.Add(date);
                     date = date.AddDays(7);
+                    currentWeekNo = Calendar.GetWeekOfYear(date, CalendarWeekRule.FirstFourDayWeek,
+                        pattern.FirstDayOfWeek);
                 }
             }
             else if (pattern.Frequency == FrequencyType.Monthly || pattern.ByMonth.Count > 0)