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

runtime/vm/zone.cc

Index: runtime/vm/zone.cc
diff --git a/runtime/vm/zone.cc b/runtime/vm/zone.cc
index 9afc8c12ffc5d944ffb622d8ad496627d78d4ffb..ee7720604b09dd45f1823fa54dded2f4b792a58f 100644
--- a/runtime/vm/zone.cc
+++ b/runtime/vm/zone.cc
@@ -216,6 +216,14 @@ void BaseZone::DumpZoneSizes() {
 #endif
 
 
+Zone::Zone()
+    : StackResource(NULL),
+      zone_(),
+      handles_(),
+      previous_(NULL) {
+}
+
+
 Zone::Zone(Isolate* isolate)
     : StackResource(isolate),
       zone_(),
@@ -230,12 +238,15 @@ Zone::Zone(Isolate* isolate)
 
 
 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);