Fix crash when posting a message to a send port with port id 0.

runtime/vm/dart_api_impl.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 "include/dart_api.h"
 #include "include/dart_mirrors_api.h"
 #include "include/dart_native_api.h"
 
 #include "platform/assert.h"
 #include "vm/class_finalizer.h"
@@ skipping 1591 matching lines @@
 }
 
 
 static uint8_t* allocator(uint8_t* ptr, intptr_t old_size, intptr_t new_size) {
   void* new_ptr = realloc(reinterpret_cast<void*>(ptr), new_size);
   return reinterpret_cast<uint8_t*>(new_ptr);
 }
 
 
 DART_EXPORT bool Dart_Post(Dart_Port port_id, Dart_Handle handle) {
+  if (port_id == ILLEGAL_PORT) {
+    return false;
+  }
   Isolate* isolate = Isolate::Current();
   DARTSCOPE(isolate);
   const Object& object = Object::Handle(isolate, Api::UnwrapHandle(handle));
   uint8_t* data = NULL;
   MessageWriter writer(&data, &allocator, false);
   writer.WriteMessage(object);
   intptr_t len = writer.BytesWritten();
   return PortMap::PostMessage(new Message(
       port_id, data, len, Message::kNormalPriority));
 }
 
 
 DART_EXPORT Dart_Handle Dart_NewSendPort(Dart_Port port_id) {
+  if (port_id == ILLEGAL_PORT) {

[zra, 2015/04/04 05:03:47]

Should this go after grabbing the current isolate so we don't try to allocate a
new error when there isn't one? That seems to be the pattern in other calls.

[Cutch, 2015/04/05 19:06:09]

Done.

+    return Api::NewError("%s: illegal port_id %" Pd64 ".",
+                         CURRENT_FUNC,
+                         port_id);
+  }
   Isolate* isolate = Isolate::Current();
   DARTSCOPE(isolate);
   CHECK_CALLBACK_STATE(isolate);
   return Api::NewHandle(isolate, SendPort::New(port_id));
 }
 
 
 DART_EXPORT Dart_Handle Dart_SendPortGetId(Dart_Handle port,
                                            Dart_Port* port_id) {
   Isolate* isolate = Isolate::Current();
@@ skipping 3902 matching lines @@
 
 
 DART_EXPORT void Dart_RegisterRootServiceRequestCallback(
     const char* name,
     Dart_ServiceRequestCallback callback,
     void* user_data) {
   Service::RegisterRootEmbedderCallback(name, callback, user_data);
 }
 
 }  // namespace dart