Fixed stack overflow issues that could occur when certain values of T…

…odo and Event are null.
rianjs · Nov 7, 2019 · 4b86b46 · 4b86b46
1 parent de891fe
commit 4b86b46
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Showing 2 changed files with 28 additions and 15 deletions.
diff --git a/v2/ical.NET/Components/Event.cs b/v2/ical.NET/Components/Event.cs
@@ -45,7 +45,7 @@ public override IDateTime DtStart
  set
  {
  base.DtStart = value;
- ExtrapolateTimes();
+ ExtrapolateTimes(2);
  }
  }
 
@@ -68,7 +68,7 @@ public virtual IDateTime DtEnd
  if (!Equals(DtEnd, value))
  {
  Properties.Set("DTEND", value);
- ExtrapolateTimes();
+ ExtrapolateTimes(0);
  }
  }
  }
@@ -102,7 +102,7 @@ public virtual TimeSpan Duration
  if (!Equals(Duration, value))
  {
  Properties.Set("DURATION", value);
- ExtrapolateTimes();
+ ExtrapolateTimes(1);
  }
  }
  }
@@ -263,20 +263,27 @@ protected override void OnDeserialized(StreamingContext context)
  {
  base.OnDeserialized(context);
 
- ExtrapolateTimes();
+ ExtrapolateTimes(-1);
  }
 
- private void ExtrapolateTimes()
+ private void ExtrapolateTimes(int source)
  {
- if (DtEnd == null && DtStart != null && Duration != default(TimeSpan))
+ /*
+ * Source values, a fix introduced to prevent stack overflow exceptions from occuring.
+ * -1 = Anybody, stack overflow could maybe still occur in this case?
+ * 0 = End
+ * 1 = Duration
+ * 2 = DtStart
+ */
+ if (DtEnd == null && DtStart != null && Duration != default(TimeSpan) && source != 0)
  {
  DtEnd = DtStart.Add(Duration);
  }
- else if (Duration == default(TimeSpan) && DtStart != null && DtEnd != null)
+ else if (Duration == default(TimeSpan) && DtStart != null && DtEnd != null && source != 1)
  {
  Duration = DtEnd.Subtract(DtStart);
  }
- else if (DtStart == null && Duration != default(TimeSpan) && DtEnd != null)
+ else if (DtStart == null && Duration != default(TimeSpan) && DtEnd != null && source != 2)
  {
  DtStart = DtEnd.Subtract(Duration);
  }

diff --git a/v2/ical.NET/Components/Todo.cs b/v2/ical.NET/Components/Todo.cs
@@ -36,7 +36,7 @@ public override IDateTime DtStart
  set
  {
  base.DtStart = value;
- ExtrapolateTimes();
+ ExtrapolateTimes(2);
  }
  }
 
@@ -49,7 +49,7 @@ public virtual IDateTime Due
  set
  {
  Properties.Set("DUE", value);
- ExtrapolateTimes();
+ ExtrapolateTimes(0);
  }
  }
 
@@ -72,7 +72,7 @@ public virtual TimeSpan Duration
  set
  {
  Properties.Set("DURATION", value);
- ExtrapolateTimes();
+ ExtrapolateTimes(1);
  }
  }
 
@@ -198,17 +198,23 @@ protected override void OnDeserializing(StreamingContext context)
  base.OnDeserializing(context);
  }
 
- private void ExtrapolateTimes()
+ private void ExtrapolateTimes(int source)
  {
- if (Due == null && DtStart != null && Duration != default(TimeSpan))
+ /*
+ * Source values, a fix introduced to prevent StackOverflow exceptions from occuring.
+ * 0 = Due
+ * 1 = Duration
+ * 2 = DtStart
+ */
+ if (Due == null && DtStart != null && Duration != default(TimeSpan) && source != 0)
  {
  Due = DtStart.Add(Duration);
  }
- else if (Duration == default(TimeSpan) && DtStart != null && Due != null)
+ else if (Duration == default(TimeSpan) && DtStart != null && Due != null && source != 1)
  {
  Duration = Due.Subtract(DtStart);
  }
- else if (DtStart == null && Duration != default(TimeSpan) && Due != null)
+ else if (DtStart == null && Duration != default(TimeSpan) && Due != null && source != 2)
  {
  DtStart = Due.Subtract(Duration);
  }