From b214af94e3cf1cc8f82ea2c3d8f3dbd48b1ac4c2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?D=C3=A1vid=20Karnok?= <akarnokd@gmail.com>
Date: Wed, 27 Jun 2018 22:40:04 +0200
Subject: [PATCH] 4.x: ElementAt don't create exception after finding the item

---
 .../Source/src/System.Reactive/Linq/Observable/ElementAt.cs  | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/Rx.NET/Source/src/System.Reactive/Linq/Observable/ElementAt.cs b/Rx.NET/Source/src/System.Reactive/Linq/Observable/ElementAt.cs
index 6efe60d4a5..f41ede707a 100644
--- a/Rx.NET/Source/src/System.Reactive/Linq/Observable/ElementAt.cs
+++ b/Rx.NET/Source/src/System.Reactive/Linq/Observable/ElementAt.cs
@@ -42,7 +42,10 @@ public override void OnNext(TSource value)
 
             public override void OnCompleted()
             {
-                ForwardOnError(new ArgumentOutOfRangeException("index"));
+                if (_i >= 0)
+                {
+                    ForwardOnError(new ArgumentOutOfRangeException("index"));
+                }
             }
         }
     }