Don't create unused OSError in Socket_Available.

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}) {
     return _RawServerSocket.bind(address, port, backlog, v6Only);
@@ skipping 554 matching lines @@
     var result = nativeRecvFrom();
     if (result is OSError) {
       reportError(result, "Receive failed");
       return null;
     }
     if (result != null) {
       // Read the next available. Available is only for the next datagram, not
       // the sum of all datagrams pending, so we need to call after each
       // receive. If available becomes > 0, the _NativeSocket will continue to
       // emit read events.
-      available = nativeAvailable();
+      var avail = nativeAvailable();
+      if (avail != null) {
+        available = avail;
+      }

[Ivan Posva, 2014/10/09 06:12:07]

available = (avail != null) avail : 1;

With the same comment about forcing the read from the socket as in the other
place nativeAvailable is called. Alternatively we could just have the native
code return a 1 instead of null. Removing the need for this adjustment.

[Anders Johnsen, 2014/10/09 06:17:07]

Done.

       totalRead += result.data.length;
     }
     readCount++;
     lastRead = timestamp;
     return result;
   }
 
   int write(List<int> buffer, int offset, int bytes) {
     if (buffer is! List) throw new ArgumentError();
     if (offset == null) offset = 0;
@@ skipping 152 matching lines @@
           writeAvailable = true;
           issueWriteEvent(delayed: false);
           continue;
         }
 
         if (i == READ_EVENT) {
           if (isListening) {
             available++;
           } else {
             var avail = nativeAvailable();
-            if (avail is int) {
+            if (avail != null) {
               available = avail;
             } else {
               // Available failed. Mark socket as having data, to ensure read
               // events, and thus reporting of this error.
               available = 1;

[Ivan Posva, 2014/10/09 06:12:07]

ditto.

[Anders Johnsen, 2014/10/09 06:17:07]

Done.

             }
             issueReadEvent();
             continue;
           }
         }
 
         var handler = eventHandlers[i];
         if (i == DESTROYED_EVENT) {
           assert(isClosing);
           assert(!isClosed);
@@ skipping 1163 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();