Decode the Dart message into a Dart_CMessage structure before calling the native port callback

runtime/vm/zone.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 "vm/zone.h"
 
 #include "platform/assert.h"
 #include "platform/utils.h"
 #include "vm/flags.h"
 #include "vm/isolate.h"
@@ skipping 198 matching lines @@
   intptr_t size = 0;
   for (Segment* s = large_segments_; s != NULL; s = s->next()) {
     size += s->size();
   }
   OS::Print("Size in bytes allocated, Total = %d Large Segments = %d\n",
             SizeInBytes(), size);
 }
 #endif
 
 
+Zone::Zone()
+    : StackResource(NULL),
+      zone_(),
+      handles_(),
+      previous_(NULL) {
+}
+
+
 Zone::Zone(Isolate* isolate)
     : StackResource(isolate),
       zone_(),
       handles_(),
       previous_(NULL) {
   // Assert that there is no current zone as we only want to scope
   // zones when transitioning from generated dart code to dart VM
   // runtime code.
   previous_ = isolate->current_zone();
   isolate->set_current_zone(this);
 }
 
 
 Zone::~Zone() {
-  ASSERT(isolate()->current_zone() == this);
-  isolate()->set_current_zone(previous_);
+  if (isolate() != NULL) {
+    ASSERT(isolate()->current_zone() == this);
+    isolate()->set_current_zone(previous_);
+  }
 }
 
 
 void Zone::VisitObjectPointers(ObjectPointerVisitor* visitor) {
+  ASSERT(isolate() != NULL);
   Zone* zone = this;
   while (zone != NULL) {
     zone->handles()->VisitObjectPointers(visitor);
     zone = zone->previous_;
   }
 }
 
 }  // namespace dart