only slice SocketAddress on success operation (#90284)

* only slice SocketAddress on success operation

* null

* completed

* feedback

* feedback

src/libraries/System.Net.Sockets/src/System/Net/Sockets/SocketAsyncContext.Unix.cs

@@ -475,9 +475,12 @@ protected override bool DoTryComplete(SocketAsyncContext context)
                     }
                     else
                     {
-                        bool result = SocketPal.TryCompleteReceiveFrom(context._socket, Buffer.Span, null, Flags, SocketAddress.Span, out int socketAddressLen, out BytesTransferred, out ReceivedFlags, out ErrorCode);
-                        SocketAddress = SocketAddress.Slice(0, socketAddressLen);
-                        return result;
+                        bool completed = SocketPal.TryCompleteReceiveFrom(context._socket, Buffer.Span, null, Flags, SocketAddress.Span, out int socketAddressLen, out BytesTransferred, out ReceivedFlags, out ErrorCode);
+                        if (completed && ErrorCode == SocketError.Success)
+                        {
+                            SocketAddress = SocketAddress.Slice(0, socketAddressLen);
+                        }
+                        return completed;
                     }
                 }
             }
@@ -508,7 +511,7 @@ private sealed class BufferListReceiveOperation : ReceiveOperation
             protected override bool DoTryComplete(SocketAsyncContext context)
             {
                 bool completed = SocketPal.TryCompleteReceiveFrom(context._socket, default(Span<byte>), Buffers, Flags, SocketAddress.Span, out int socketAddressLen, out BytesTransferred, out ReceivedFlags, out ErrorCode);
-                if (ErrorCode == SocketError.Success)
+                if (completed && ErrorCode == SocketError.Success)
                 {
                     SocketAddress = SocketAddress.Slice(0, socketAddressLen);
                 }
@@ -542,7 +545,7 @@ private sealed unsafe class BufferPtrReceiveOperation : ReceiveOperation
             protected override bool DoTryComplete(SocketAsyncContext context)
             {
                 bool completed = SocketPal.TryCompleteReceiveFrom(context._socket, new Span<byte>(BufferPtr, Length), null, Flags, SocketAddress.Span, out int socketAddressLen, out BytesTransferred, out ReceivedFlags, out ErrorCode);
-                if (ErrorCode == SocketError.Success)
+                if (completed && ErrorCode == SocketError.Success)
                 {
                     SocketAddress = SocketAddress.Slice(0, socketAddressLen);
                 }
@@ -569,7 +572,7 @@ private sealed class ReceiveMessageFromOperation : ReadOperation
             protected override bool DoTryComplete(SocketAsyncContext context)
             {
                 bool completed = SocketPal.TryCompleteReceiveMessageFrom(context._socket, Buffer.Span, Buffers, Flags, SocketAddress, out int socketAddressLen, IsIPv4, IsIPv6, out BytesTransferred, out ReceivedFlags, out IPPacketInformation, out ErrorCode);
-                if (ErrorCode == SocketError.Success)
+                if (completed && ErrorCode == SocketError.Success)
                 {
                     SocketAddress = SocketAddress.Slice(0, socketAddressLen);
                 }
@@ -599,7 +602,7 @@ private sealed unsafe class BufferPtrReceiveMessageFromOperation : ReadOperation
             protected override bool DoTryComplete(SocketAsyncContext context)
             {
                 bool completed = SocketPal.TryCompleteReceiveMessageFrom(context._socket, new Span<byte>(BufferPtr, Length), null, Flags, SocketAddress!, out int socketAddressLen, IsIPv4, IsIPv6, out BytesTransferred, out ReceivedFlags, out IPPacketInformation, out ErrorCode);
-                if (ErrorCode == SocketError.Success)
+                if (completed && ErrorCode == SocketError.Success)
                 {
                     SocketAddress = SocketAddress.Slice(0, socketAddressLen);
                 }

src/libraries/System.Net.Sockets/src/System/Net/Sockets/SocketAsyncEventArgs.Unix.cs

@@ -368,10 +368,7 @@ private static SocketError FinishOperationConnect()
 
         private void UpdateReceivedSocketAddress(SocketAddress socketAddress)
         {
-            if (_socketAddressSize > 0)
-            {
-                socketAddress.Size = _socketAddressSize;
-            }
+            socketAddress.Size = _socketAddressSize;
         }
 
         partial void FinishOperationReceiveMessageFrom();

src/libraries/System.Net.Sockets/src/System/Net/Sockets/SocketPal.Unix.cs

@@ -152,6 +152,8 @@ private static unsafe int SysReceive(SafeSocketHandle socket, SocketFlags flags,
                     Count = (UIntPtr)buffer.Length
                 };
 
+                Debug.Assert(socketAddress.Length != 0 || sockAddr == null);
+
                 var messageHeader = new Interop.Sys.MessageHeader {
                     SocketAddress = sockAddr,
                     SocketAddressLen = socketAddress.Length,
@@ -468,7 +470,6 @@ private static unsafe int SysReceive(SafeSocketHandle socket, SocketFlags flags,
         private static unsafe int SysReceiveMessageFrom(SafeSocketHandle socket, SocketFlags flags, Span<byte> buffer, Span<byte> socketAddress, out int socketAddressLen, bool isIPv4, bool isIPv6, out SocketFlags receivedFlags, out IPPacketInformation ipPacketInformation, out Interop.Error errno)
         {
             Debug.Assert(socket.IsSocket);
-            Debug.Assert(socketAddress != null, "Expected non-null socketAddress");
 
             int cmsgBufferLen = Interop.Sys.GetControlMessageBufferSize(Convert.ToInt32(isIPv4), Convert.ToInt32(isIPv6));
             byte* cmsgBuffer = stackalloc byte[cmsgBufferLen];
@@ -484,6 +485,8 @@ private static unsafe int SysReceiveMessageFrom(SafeSocketHandle socket, SocketF
                     Count = (UIntPtr)buffer.Length
                 };
 
+                Debug.Assert(socketAddress.Length != 0 || rawSocketAddress == null);
+
                 messageHeader = new Interop.Sys.MessageHeader {
                     SocketAddress = rawSocketAddress,
                     SocketAddressLen = socketAddress.Length,
@@ -1234,7 +1237,7 @@ public static SocketError Receive(SafeSocketHandle handle, IList<ArraySegment<by
             }
             else
             {
-                if (!TryCompleteReceiveFrom(handle, buffers, socketFlags, null, out int _, out bytesTransferred, out _, out errorCode))
+                if (!TryCompleteReceiveFrom(handle, buffers, socketFlags, Span<byte>.Empty, out int _, out bytesTransferred, out _, out errorCode))
                 {
                     errorCode = SocketError.WouldBlock;
                 }