address co-pilot review #3930 (review)

Author: v-birschick-msft

lib/netstd/Thrift/Transport/Client/THttpPerCallTransport.cs

@@ -72,13 +72,13 @@ public override async Task FlushAsync(
 
             _request.Position = 0;
             _response = await _parent.SendAsync(_request,cancellationToken);
-            _sent = true;
 
 #if NET5_0_OR_GREATER
             _responseStream = await _response.Content.ReadAsStreamAsync(cancellationToken);
 #else
             _responseStream = await _response.Content.ReadAsStreamAsync();
 #endif
+            _sent = true;
         }
 
         public override async ValueTask<int> ReadAsync(

lib/netstd/Thrift/Transport/Client/THttpTransport.cs

@@ -245,7 +245,15 @@ public override async Task FlushAsync(CancellationToken cancellationToken)
                 {
                     contentStream.Headers.ContentType = ContentType ?? new MediaTypeHeaderValue(@"application/x-thrift");
 
-                    var response = (await _httpClient.PostAsync(_uri, contentStream, cancellationToken)).EnsureSuccessStatusCode();
+                    using var request = new HttpRequestMessage(HttpMethod.Post, _uri)
+                    {
+                        Content = contentStream
+                    };
+
+                    var response = (await _httpClient.SendAsync(
+                        request,
+                        HttpCompletionOption.ResponseHeadersRead,
+                        cancellationToken)).EnsureSuccessStatusCode();
 
                     _inputStream?.Dispose();
 #if NET5_0_OR_GREATER
@@ -366,10 +374,6 @@ internal async Task<HttpResponseMessage> SendAsync(Stream request, CancellationT
                 response?.Dispose();
                 throw new TTransportException(TTransportException.ExceptionType.Unknown, ex.Message, ex);
             }
-            finally
-            {
-                ResetMessageSizeAndConsumedBytes();
-            }
         }
     }
 }