Do not set HttpRequestMessage content when no PostData

src/Elasticsearch.Net/Connection/Content/RequestDataContent.cs

@@ -25,8 +25,7 @@ namespace Elasticsearch.Net
 	internal class RequestDataContent : HttpContent
 	{
 		private readonly RequestData _requestData;
-		private readonly Func<PostData, CompleteTaskOnCloseStream, RequestDataContent, TransportContext, Task> _onStreamAvailable;
-
+		private readonly Func<RequestData, CompleteTaskOnCloseStream, RequestDataContent, TransportContext, Task> _onStreamAvailable;
 
 		public RequestDataContent(RequestData requestData)
 		{
@@ -35,14 +34,17 @@ public RequestDataContent(RequestData requestData)
 			if (requestData.HttpCompression)
 				Headers.ContentEncoding.Add("gzip");
 
-			Task OnStreamAvailable(PostData data, Stream stream, HttpContent content, TransportContext context)
+			Task OnStreamAvailable(RequestData data, Stream stream, HttpContent content, TransportContext context)
 			{
-				if (_requestData.HttpCompression)
+				if (data.HttpCompression)
 					stream = new GZipStream(stream, CompressionMode.Compress, false);
+
 				using(stream)
-					data.Write(stream, requestData.ConnectionSettings);
+					data.PostData.Write(stream, data.ConnectionSettings);
+
 				return Task.CompletedTask;
 			}
+
 			_onStreamAvailable = OnStreamAvailable;
 		}
 		public RequestDataContent(RequestData requestData, CancellationToken token)
@@ -52,13 +54,15 @@ public RequestDataContent(RequestData requestData, CancellationToken token)
 			if (requestData.HttpCompression)
 				Headers.ContentEncoding.Add("gzip");
 
-			async Task OnStreamAvailable(PostData data, Stream stream, HttpContent content, TransportContext context)
+			async Task OnStreamAvailable(RequestData data, Stream stream, HttpContent content, TransportContext context)
 			{
-				if (_requestData.HttpCompression)
+				if (data.HttpCompression)
 					stream = new GZipStream(stream, CompressionMode.Compress, false);
+
 				using (stream)
-					await data.WriteAsync(stream, requestData.ConnectionSettings, token).ConfigureAwait(false);
+					await data.PostData.WriteAsync(stream, data.ConnectionSettings, token).ConfigureAwait(false);
 			}
+
 			_onStreamAvailable = OnStreamAvailable;
 		}
 
@@ -73,14 +77,9 @@ async Task OnStreamAvailable(PostData data, Stream stream, HttpContent content,
 		[SuppressMessage("Microsoft.Design", "CA1031:DoNotCatchGeneralExceptionTypes", Justification = "Exception is passed as task result.")]
 		protected override async Task SerializeToStreamAsync(Stream stream, TransportContext context)
 		{
-
-			var data = _requestData.PostData;
-			if (data == null) return;
-
 			var serializeToStreamTask = new TaskCompletionSource<bool>();
-
 			var wrappedStream = new CompleteTaskOnCloseStream(stream, serializeToStreamTask);
-            await _onStreamAvailable(data, wrappedStream, this, context).ConfigureAwait(false);
+            await _onStreamAvailable(_requestData, wrappedStream, this, context).ConfigureAwait(false);
             await serializeToStreamTask.Task.ConfigureAwait(false);
 		}
 
@@ -113,7 +112,6 @@ protected override void Dispose(bool disposing)
 				base.Dispose();
 			}
 
-
 			public override void Close() => _serializeToStreamTask.TrySetResult(true);
 		}
 
@@ -195,6 +193,8 @@ public override IAsyncResult BeginWrite(byte[] buffer, int offset, int count, As
 			public override void EndWrite(IAsyncResult asyncResult) => _innerStream.EndWrite(asyncResult);
 
 			public override void WriteByte(byte value) => _innerStream.WriteByte(value);
+
+			public override void Close() => _innerStream.Close();
 		}
 	}
 }

src/Elasticsearch.Net/Connection/HttpConnection.cs

@@ -57,7 +57,10 @@ public virtual TResponse Request<TResponse>(RequestData requestData)
 			try
 			{
 				var requestMessage = CreateHttpRequestMessage(requestData);
-				SetContent(requestMessage, requestData);
+
+				if (requestData.PostData != null)
+					SetContent(requestMessage, requestData);
+
 				using(requestMessage?.Content ?? (IDisposable)Stream.Null)
 				using (var d = DiagnosticSource.Diagnose<RequestData, int?>(DiagnosticSources.HttpConnection.SendAndReceiveHeaders, requestData))
 				{
@@ -107,8 +110,11 @@ public virtual async Task<TResponse> RequestAsync<TResponse>(RequestData request
 			try
 			{
 				var requestMessage = CreateHttpRequestMessage(requestData);
-				SetAsyncContent(requestMessage, requestData, cancellationToken);
-				using(requestMessage?.Content ?? (IDisposable)Stream.Null) 
+
+				if (requestData.PostData != null)
+					SetAsyncContent(requestMessage, requestData, cancellationToken);
+
+				using(requestMessage?.Content ?? (IDisposable)Stream.Null)
 				using (var d = DiagnosticSource.Diagnose<RequestData, int?>(DiagnosticSources.HttpConnection.SendAndReceiveHeaders, requestData))
 				{
 					responseMessage = await client.SendAsync(requestMessage, HttpCompletionOption.ResponseHeadersRead, cancellationToken).ConfigureAwait(false);

src/Tests/Tests.Reproduce/GithubIssue3907.cs

@@ -0,0 +1,32 @@
+using System;
+using System.Net;
+using Elastic.Xunit.XunitPlumbing;
+using FluentAssertions;
+using Nest;
+using Tests.Core.ManagedElasticsearch.Clusters;
+using Tests.Domain;
+
+namespace Tests.Reproduce
+{
+	public class GithubIssue3907 : IClusterFixture<ReadOnlyCluster>
+	{
+		private readonly IntrusiveOperationCluster _cluster;
+
+		// use intrusive operation cluster because we're changing the underlying http handler
+		// and this cluster runs with a max concurrency of 1, so changing http handler
+		// will not affect other integration tests
+		public GithubIssue3907(IntrusiveOperationCluster cluster) => _cluster = cluster;
+
+		[I]
+		public void NotUsingSocketsHttpHandlerDoesNotCauseException()
+		{
+			AppContext.SetSwitch("System.Net.Http.UseSocketsHttpHandler", false);
+
+			var response = _cluster.Client.Indices.Exists("non_existent_index");
+			response.ApiCall.HttpStatusCode.Should().Be(404);
+			response.OriginalException.Should().BeNull();
+
+			AppContext.SetSwitch("System.Net.Http.UseSocketsHttpHandler", true);
+		}
+	}
+}