Don't create unused OSError in Socket_Available.

runtime/bin/socket.cc

 // 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.
 
 #include "bin/io_buffer.h"
 #include "bin/isolate_data.h"
 #include "bin/dartutils.h"
 #include "bin/socket.h"
 #include "bin/thread.h"
 #include "bin/utils.h"
@@ skipping 65 matching lines @@
 }
 
 
 void FUNCTION_NAME(Socket_Available)(Dart_NativeArguments args) {
   intptr_t socket =
       Socket::GetSocketIdNativeField(Dart_GetNativeArgument(args, 0));
   intptr_t available = Socket::Available(socket);
   if (available >= 0) {
     Dart_SetReturnValue(args, Dart_NewInteger(available));
   } else {
-    Dart_SetReturnValue(args, DartUtils::NewDartOSError());
+    // Available failed. Mark socket as having data, to trigger a future read
+    // event where the actual error can be reported.
+    Dart_SetReturnValue(args, Dart_NewInteger(1));
   }
 }
 
 
 void FUNCTION_NAME(Socket_Read)(Dart_NativeArguments args) {
   static bool short_socket_reads = Dart_IsVMFlagSet("short_socket_read");
   intptr_t socket =
       Socket::GetSocketIdNativeField(Dart_GetNativeArgument(args, 0));
   int64_t length = 0;
   if (DartUtils::GetInt64Value(Dart_GetNativeArgument(args, 1), &length)) {
@@ skipping 589 matching lines @@
 intptr_t Socket::GetSocketIdNativeField(Dart_Handle socket_obj) {
   intptr_t socket = 0;
   Dart_Handle err =
       Dart_GetNativeInstanceField(socket_obj, kSocketIdNativeField, &socket);
   if (Dart_IsError(err)) Dart_PropagateError(err);
   return socket;
 }
 
 }  // namespace bin
 }  // namespace dart