[System] Don't send response on empty stream write. Fixes #47549

1 files changed, 29 insertions, 2 deletions

diff --git a/mcs/class/System/Test/System.Net/HttpListenerRequestTest.cs b/mcs/class/System/Test/System.Net/HttpListenerRequestTest.cs
index 18dedcae32d..2f24f73ec0d 100644
--- a/mcs/class/System/Test/System.Net/HttpListenerRequestTest.cs
+++ b/mcs/class/System/Test/System.Net/HttpListenerRequestTest.cs
@@ -34,6 +34,7 @@ using System.Net.NetworkInformation;
 using System.Net.Sockets;
 using System.Text;
 using System.Collections.Generic;
+using System.Threading.Tasks;
 
 using NUnit.Framework;
 
@@ -254,12 +255,38 @@ namespace MonoTests.System.Net
 			var request = (HttpWebRequest) WebRequest.Create (rawUrl);
 			request.GetResponseAsync ();
 
-			if(!contextTask.Wait (1000))
-				Assert.Fail ("Timeout");
+			Assert.IsTrue (contextTask.Wait (1000));
 
 			Assert.AreEqual (expectedUrl, contextTask.Result.Request.Url.AbsoluteUri);
 
 			listener.Close ();
 		}
+
+		[Test]
+#if FEATURE_NO_BSD_SOCKETS
+		[ExpectedException (typeof (PlatformNotSupportedException))]
+#endif
+		public void EmptyWrite ()
+		{
+			var prefix = "http://localhost:" + NetworkHelpers.FindFreePort () + "/";
+
+			HttpListener listener = new HttpListener ();
+			listener.Prefixes.Add (prefix);
+			listener.Start ();
+
+			Task.Run (() => {
+				var context = listener.GetContext ();
+
+				var s = context.Response.OutputStream;
+				s.Write (new byte[10], 0, 0);
+				return;
+			});
+
+			var request = (HttpWebRequest)WebRequest.Create (prefix);
+			var rsp = request.GetResponseAsync ();
+			Assert.IsFalse (rsp.Wait (1000), "Don't send on empty write");
+
+			listener.Close ();
+		}
 	}
 }