Fix handling of context creation failure since r13978.

src/bootstrapper.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 285 matching lines @@
   v->Synchronize(VisitorSynchronization::kExtensions);
 }
 
 
 Handle<Context> Bootstrapper::CreateEnvironment(
     Handle<Object> global_object,
     v8::Handle<v8::ObjectTemplate> global_template,
     v8::ExtensionConfiguration* extensions) {
   HandleScope scope(isolate_);
   Genesis genesis(isolate_, global_object, global_template, extensions);
-  Handle<Object> context(isolate_->global_handles()->Create(*genesis.result()));
-  Handle<Context> env = Handle<Context>::cast(context);
-  if (!env.is_null()) {
+  if (!genesis.result().is_null()) {
+    Handle<Object> ctx(isolate_->global_handles()->Create(*genesis.result()));
+    Handle<Context> env = Handle<Context>::cast(ctx);
     if (InstallExtensions(env, extensions)) {
       return env;
     }
   }
   return Handle<Context>();
 }
 
 
 static void SetObjectPrototype(Handle<JSObject> object, Handle<Object> proto) {
   // object.__proto__ = proto;
@@ skipping 2169 matching lines @@
   return from + sizeof(NestingCounterType);
 }
 
 
 // Called when the top-level V8 mutex is destroyed.
 void Bootstrapper::FreeThreadResources() {
   ASSERT(!IsActive());
 }
 
 } }  // namespace v8::internal