Make Socket address and port getters available after the socket is closed

runtime/bin/socket_patch.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 patch class RawServerSocket {
   /* patch */ static Future<RawServerSocket> bind(address,
                                                   int port,
                                                   {int backlog: 0,
                                                    bool v6Only: false,
                                                    bool shared: false}) {
@@ skipping 415 matching lines @@
               result = socket.nativeCreateBindConnect(
                   address._in_addr, port, sourceAddress._in_addr);
             }
             if (result is OSError) {
               // Keep first error, if present.
               if (error == null) {
                 error = createError(result, "Connection failed", address, port);
               }
               connectNext();
             } else {
-              socket.port;  // Query the local port, for error messages.
+              // Query the local port, for error messages.
+              socket.port;
               // Set up timer for when we should retry the next address
               // (if any).
               var duration = address.isLoopback ?
                   _RETRY_DURATION_LOOPBACK :
                   _RETRY_DURATION;
               var timer = new Timer(duration, connectNext);
               connecting[socket] = timer;
               // Setup handlers for receiving the first write event which
               // indicate that the socket is fully connected.
               socket.setHandlers(
@@ skipping 224 matching lines @@
     var socket = new _NativeSocket.normal();
     if (nativeAccept(socket) != true) return null;
     socket.localPort = localPort;
     socket.localAddress = address;
     totalRead += 1;
     lastRead = timestamp;
     return socket;
   }
 
   int get port {
+    if (localPort != 0) return localPort;
     if (isClosing || isClosed) throw const SocketException.closed();
-    if (localPort != 0) return localPort;
     var result = nativeGetPort();
     if (result is OSError) throw result;
     return localPort = result;
   }
 
   int get remotePort {
     if (isClosing || isClosed) throw const SocketException.closed();
     var result = nativeGetRemotePeer();
     if (result is OSError) throw result;
     return result[1];
   }
 
-  InternetAddress get address {
-    if (isClosing || isClosed) throw const SocketException.closed();
-    return localAddress;
-  }
+  InternetAddress get address => localAddress;
 
   InternetAddress get remoteAddress {
     if (isClosing || isClosed) throw const SocketException.closed();
     var result = nativeGetRemotePeer();
     if (result is OSError) throw result;
     var addr = result[0];
     var type = new InternetAddressType._from(addr[0]);
     return new _InternetAddress(addr[1], null, addr[2]);
   }
 
@@ skipping 1286 matching lines @@
                        String address,
                        List<int> in_addr,
                        int port) {
   return new Datagram(
       data,
       new _InternetAddress(address, null, in_addr),
       port);
 }
 
 String _socketsStats() => _SocketsObservatory.toJSON();