Breaking change: Socket.LocalEndPoint updated on SendToAsync(SocketAsyncEventArgs e) #20949

Socket.LocalEndPoint updated on SendToAsync(SocketAsyncEventArgs e)

Behavioral breaking change after fixing a bug reported in dotnet/runtime#915 (fixed by dotnet/runtime#808).

Version introduced

.NET 5 RC1

Old behavior

Unlike other variants of SendTo, the SendToAsync(SocketAsyncEventArgs e) method did not alter the LocalEndpoint property on the socket instance.

New behavior

Just like in case of SendTo or BeginSendTo/EndSendTo, the property LocalEndpoint returns the (implicitly bound) socket's local address after the successful completion of SendToAsync(SocketAsyncEventArgs e).

Reason for change

Fix a bug, and consolidate behavior accross sendto variants.

Recommended action

Alter code that assumes that SendToAsync will keep LocalEndpoint's value unchanged/null.

Category

• ASP.NET Core
• C#
• Code analysis
• Core .NET libraries
• Cryptography
• Data
• Debugger
• Deployment
• Globalization
• Interop
• JIT
• LINQ
• Managed Extensibility Framework (MEF)
• MSBuild
• Networking
• Printing
• Security
• Serialization
• Visual Basic
• Windows Forms
• Windows Presentation Foundation (WPF)
• XML, XSLT

Affected APIs

Socket.SendToAsync(SocketAsyncEventArgs e)
Socket.LocalEndpoint

Issue metadata

• Issue type: breaking-change