Register existing isolates when service isolate is started

runtime/bin/main.cc

 // Copyright (c) 2012, 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 <stdlib.h>
 #include <string.h>
 #include <stdio.h>
 
 #include "include/dart_api.h"
 #include "include/dart_debugger_api.h"
@@ skipping 923 matching lines @@
     bool print_msg = verbose_debug_seen || (debug_port == 0);
     debug_port = DebuggerConnectionHandler::StartHandler(debug_ip, debug_port);
     if (print_msg) {
       Log::Print("Debugger listening on port %d\n", debug_port);
     }
   }
 
   // Start event handler.
   EventHandler::Start();
 
+  ASSERT(Dart_CurrentIsolate() == NULL);
   // Start the VM service isolate, if necessary.
   if (start_vm_service) {
     ASSERT(vm_service_server_port >= 0);
     bool r = VmService::Start(vm_service_server_port);
     if (!r) {
       Log::PrintErr("Could not start VM Service isolate %s\n",
                     VmService::GetErrorMessage());
     }
     Dart_RegisterIsolateServiceRequestCallback(
         "io", &ServiceRequestHandler, NULL);
   }
+  ASSERT(Dart_CurrentIsolate() == NULL);
 
   // Call CreateIsolateAndSetup which creates an isolate and loads up
   // the specified application script.
   char* error = NULL;
   bool is_compile_error = false;
   char* isolate_name = BuildIsolateName(script_name, "main");
   IsolateData* isolate_data = new IsolateData(script_name);
   Dart_Isolate isolate = CreateIsolateAndSetupHelper(script_name,
                                                      "main",
                                                      isolate_data,
@@ skipping 130 matching lines @@
   exit(Process::GlobalExitCode());
 }
 
 }  // namespace bin
 }  // namespace dart
 
 int main(int argc, char** argv) {
   dart::bin::main(argc, argv);
   UNREACHABLE();
 }