V8 API: Add a missing NULL check into Isolate::GetCurrentContext().

src/api.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 6520 matching lines @@
 
 CpuProfiler* Isolate::GetCpuProfiler() {
   i::CpuProfiler* cpu_profiler =
       reinterpret_cast<i::Isolate*>(this)->cpu_profiler();
   return reinterpret_cast<CpuProfiler*>(cpu_profiler);
 }
 
 
 v8::Local<v8::Context> Isolate::GetCurrentContext() {
   i::Isolate* internal_isolate = reinterpret_cast<i::Isolate*>(this);
-  i::Handle<i::Object> current = internal_isolate->native_context();
-  if (current.is_null()) return Local<Context>();
-  i::Handle<i::Context> context = i::Handle<i::Context>::cast(current);
-  return Utils::ToLocal(context);
+  i::Context* context = internal_isolate->context();
+  if (context == NULL) return Local<Context>();
+  i::Context* native_context = context->global_object()->native_context();
+  if (native_context == NULL) return Local<Context>();
+  return Utils::ToLocal(i::Handle<i::Context>(native_context));
 }
 
 
 void Isolate::SetObjectGroupId(const Persistent<Value>& object,
                                UniqueId id) {
   i::Isolate* internal_isolate = reinterpret_cast<i::Isolate*>(this);
   internal_isolate->global_handles()->SetObjectGroupId(
       Utils::OpenPersistent(object).location(),
       id);
 }
@@ skipping 1495 matching lines @@
   Isolate* isolate = reinterpret_cast<Isolate*>(info.GetIsolate());
   Address callback_address =
       reinterpret_cast<Address>(reinterpret_cast<intptr_t>(callback));
   VMState<EXTERNAL> state(isolate);
   ExternalCallbackScope call_scope(isolate, callback_address);
   return callback(info);
 }
 
 
 } }  // namespace v8::internal