IO v2: Handle illegal arguments to socket writes

runtime/vm/dart_api_impl.cc

Index: runtime/vm/dart_api_impl.cc
===================================================================
--- runtime/vm/dart_api_impl.cc	(revision 17848)
+++ runtime/vm/dart_api_impl.cc	(working copy)
@@ -1,4 +1,4 @@
-// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
+// 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.
 
@@ -2030,7 +2030,6 @@
 }
 
 
-// TODO(hpayer): value should always be smaller then 0xff. Add error handling.
 #define GET_LIST_ELEMENT_AS_BYTES(isolate, type, obj, native_array, offset,    \
                                   length)                                      \
   const type& array = type::Cast(obj);                                         \
@@ -2039,8 +2038,15 @@
     for (int i = 0; i < length; i++) {                                         \
       element = array.At(offset + i);                                          \
       if (!element.IsInteger()) {                                              \
-        return Api::NewError("%s expects the argument 'list' to be "           \
-                             "a List of int", CURRENT_FUNC);                   \
+      Dart_Handle argument_error_class =                                       \
+          Dart_GetClass(                                                       \
+              Dart_LookupLibrary(Dart_NewStringFromCString("dart:core")),      \
+                                 Dart_NewStringFromCString("ArgumentError"));  \
+      Dart_Handle args[1];                                                     \
+      args[0] = Dart_NewStringFromCString("List contains non-int elements");   \
+      Dart_Handle exception =                                                  \
+          Dart_New(argument_error_class, Dart_Null(), 1, args);                \
+        return Dart_ThrowException(exception);                                 \
       }                                                                        \
       const Integer& integer = Integer::Cast(element);                         \
       native_array[i] = static_cast<uint8_t>(integer.AsInt64Value() & 0xff);   \