Use BinaryData.Empty instead of bespoke solution in SCM and Azure.Core (Azure#46669)

* Fix 41034

* update CHANGELOG

Author: annelo-msft

sdk/core/Azure.Core/CHANGELOG.md

@@ -10,6 +10,8 @@
 
 ### Other Changes
 
+- Use `BinaryData.Empty` for `PipelineResponse.Content` when HTTP message has no content.
+
 ## 1.44.1 (2024-10-09)
 
 ### Other Changes

sdk/core/Azure.Core/src/Response.cs

@@ -41,9 +41,6 @@ public abstract class Response : IDisposable
         /// </summary>
         public virtual ResponseHeaders Headers => new ResponseHeaders(this);
 
-        // TODO(matell): The .NET Framework team plans to add BinaryData.Empty in dotnet/runtime#49670, and we can use it then.
-        private static readonly BinaryData s_EmptyBinaryData = new BinaryData(Array.Empty<byte>());
-
         /// <summary>
         /// Gets the contents of HTTP response, if it is available.
         /// </summary>
@@ -56,7 +53,7 @@ public virtual BinaryData Content
             {
                 if (ContentStream == null)
                 {
-                    return s_EmptyBinaryData;
+                    return BinaryData.Empty;
                 }
 
                 MemoryStream? memoryContent = ContentStream as MemoryStream;

sdk/core/System.ClientModel/CHANGELOG.md

@@ -10,6 +10,8 @@
 
 ### Other Changes
 
+- Use `BinaryData.Empty` for `PipelineResponse.Content` when HTTP message has no content ([#46669](https://github.com/Azure/azure-sdk-for-net/pull/46669)).
+
 ## 1.2.1 (2024-10-09)
 
 ### Bugs Fixed

sdk/core/System.ClientModel/src/Message/PipelineResponse.cs

@@ -12,9 +12,6 @@ namespace System.ClientModel.Primitives;
 /// </summary>
 public abstract class PipelineResponse : IDisposable
 {
-    // TODO(matell): The .NET Framework team plans to add BinaryData.Empty in dotnet/runtime#49670, and we can use it then.
-    internal static readonly BinaryData s_EmptyBinaryData = new(Array.Empty<byte>());
-
     /// <summary>
     /// Gets the status code of the HTTP response.
     /// </summary>

sdk/core/System.ClientModel/src/Pipeline/HttpClientPipelineTransport.Response.cs

@@ -100,7 +100,7 @@ private async ValueTask<BinaryData> BufferContentSyncOrAsync(CancellationToken c
             {
                 // Content is not buffered but there is no source stream.
                 // Our contract from Azure.Core is to return BinaryData.Empty in this case.
-                _bufferedContent = s_EmptyBinaryData;
+                _bufferedContent = BinaryData.Empty;
                 return _bufferedContent;
             }