From 9687079723d340af15add573863a61c10d359c64 Mon Sep 17 00:00:00 2001
From: Cesar Blum Silveira <cesars@microsoft.com>
Date: Tue, 19 Sep 2017 14:09:09 -0700
Subject: [PATCH] Check if HTTP/2 frame writer has already been aborted.

---
 src/Kestrel.Core/Internal/Http2/Http2FrameWriter.cs | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/Kestrel.Core/Internal/Http2/Http2FrameWriter.cs b/src/Kestrel.Core/Internal/Http2/Http2FrameWriter.cs
index 569d1e298e..a8c85e7b68 100644
--- a/src/Kestrel.Core/Internal/Http2/Http2FrameWriter.cs
+++ b/src/Kestrel.Core/Internal/Http2/Http2FrameWriter.cs
@@ -35,6 +35,11 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http2
         {
             lock (_writeLock)
             {
+                if (_completed)
+                {
+                    return;
+                }
+
                 _completed = true;
                 _outputReader.CancelPendingRead();
                 _outputWriter.Complete(ex);