Take care of exceptions when accessing out-of-range elements

Author: FlorianRappl

AngleSharp.Scripting.JavaScript/DomNodeInstance.cs

@@ -41,9 +41,16 @@ public override PropertyDescriptor GetOwnProperty(String propertyName)
             if (_numericIndexer != null && Int32.TryParse(propertyName, out numericIndex))
             {
                 var args = new Object[] { numericIndex };
-                var orig = _numericIndexer.GetMethod.Invoke(_value, args);
-                var prop = orig != null ? orig.ToJsValue(_engine) : JsValue.Undefined;
-                return new PropertyDescriptor(prop, false, false, false);
+
+                try
+                {
+                    var orig = _numericIndexer.GetMethod.Invoke(_value, args);
+                    return new PropertyDescriptor(orig.ToJsValue(_engine), false, false, false);
+                }
+                catch
+                {
+                    return new PropertyDescriptor(JsValue.Undefined, false, false, false);
+                }
             }
 
             //  Else a string property

AngleSharp.Scripting.JavaScript/EngineInstance.cs

@@ -8,13 +8,19 @@
 
     sealed class EngineInstance
     {
+        #region Fields
+
         readonly Dictionary<Object, DomNodeInstance> _objects;
         readonly Engine _engine;
         readonly LexicalEnvironment _lexicals;
         readonly LexicalEnvironment _variables;
         readonly DomNodeInstance _window;
         readonly DomConstructors _constructors;
 
+        #endregion
+
+        #region ctor
+
         public EngineInstance(IWindow window, IDictionary<String, Object> assignments)
         {
             _objects = new Dictionary<Object, DomNodeInstance>();
@@ -37,6 +43,10 @@ public EngineInstance(IWindow window, IDictionary<String, Object> assignments)
             this.AddInstances(_window, this.GetType());
         }
 
+        #endregion
+
+        #region Properties
+
         public DomNodeInstance Window
         {
             get { return _window; }
@@ -62,6 +72,10 @@ public Engine Jint
             get { return _engine; }
         }
 
+        #endregion
+
+        #region Methods
+
         public DomNodeInstance GetDomNode(Object obj)
         {
             var domNodeInstance = default(DomNodeInstance);
@@ -80,5 +94,7 @@ public void RunScript(String source)
             _engine.Execute(source);
             _engine.LeaveExecutionContext();
         }
+
+        #endregion
     }
 }