From 479758227926728aeadc2d3e7cb4b470c089756d Mon Sep 17 00:00:00 2001
From: Justin Kotalik <jukotali@microsoft.com>
Date: Fri, 28 Aug 2020 16:25:42 -0700
Subject: [PATCH] Call inner disable buffering feature (#25251)

* Call inner disable buffering feature

* Update StreamResponseBodyFeature.cs
---
 .../Http/src/StreamResponseBodyFeature.cs     |  3 +-
 .../StreamResponseBodyFeatureTests.cs         | 31 +++++++++++++++++++
 2 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/src/Http/Http/src/StreamResponseBodyFeature.cs b/src/Http/Http/src/StreamResponseBodyFeature.cs
index 717b5c08d2..7e7ccae17c 100644
--- a/src/Http/Http/src/StreamResponseBodyFeature.cs
+++ b/src/Http/Http/src/StreamResponseBodyFeature.cs
@@ -71,10 +71,11 @@ namespace Microsoft.AspNetCore.Http
         }
 
         /// <summary>
-        /// Not supported.
+        /// Opts out of write buffering for the response.
         /// </summary>
         public virtual void DisableBuffering()
         {
+            PriorFeature?.DisableBuffering();
         }
 
         /// <summary>
diff --git a/src/Http/Http/test/Features/StreamResponseBodyFeatureTests.cs b/src/Http/Http/test/Features/StreamResponseBodyFeatureTests.cs
index a7624e0969..0e6c2a4ea9 100644
--- a/src/Http/Http/test/Features/StreamResponseBodyFeatureTests.cs
+++ b/src/Http/Http/test/Features/StreamResponseBodyFeatureTests.cs
@@ -41,6 +41,22 @@ namespace Microsoft.AspNetCore.Http.Features
             //Assert
             Assert.Equal(1, streamResponseBodyFeature.StartCalled);
         }
+
+        [Fact]
+        public void DisableBufferingCallsInnerFeature()
+        {
+            // Arrange
+            var stream = new MemoryStream();
+
+            var innerFeature = new InnerDisableBufferingFeature(stream, null);
+            var streamResponseBodyFeature = new StreamResponseBodyFeature(stream, innerFeature);
+
+            // Act
+            streamResponseBodyFeature.DisableBuffering();
+
+            //Assert
+            Assert.True(innerFeature.DisableBufferingCalled);
+        }
     }
 
     public class TestStreamResponseBodyFeature : StreamResponseBodyFeature
@@ -59,4 +75,19 @@ namespace Microsoft.AspNetCore.Http.Features
 
         public int StartCalled { get; private set; }
     }
+
+    public class InnerDisableBufferingFeature : StreamResponseBodyFeature
+    {
+        public InnerDisableBufferingFeature(Stream stream, IHttpResponseBodyFeature priorFeature)
+            : base(stream, priorFeature)
+        {
+        }
+
+        public override void DisableBuffering()
+        {
+            DisableBufferingCalled = true;
+        }
+
+        public bool DisableBufferingCalled { get; set; }
+    }
 }