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

test/cctest/test-api.cc

Index: test/cctest/test-api.cc
diff --git a/test/cctest/test-api.cc b/test/cctest/test-api.cc
index 8f96a4a9d1637784c0cc1175bfb72a6af7a993f3..5debeeb33ed98465436e364e4c778e4e7647234f 100755
--- a/test/cctest/test-api.cc
+++ b/test/cctest/test-api.cc
@@ -14315,6 +14315,18 @@ static v8::Handle<Value> GetCallingContextCallback(const v8::Arguments& args) {
 }
 
 
+THREADED_TEST(GetCurrentContextWhenNotInContext) {
+  i::Isolate* isolate = i::Isolate::Current();
+  CHECK(isolate != NULL);
+  CHECK(isolate->context() == NULL);
+  v8::Isolate* v8_isolate = reinterpret_cast<v8::Isolate*>(isolate);
+  v8::HandleScope scope(v8_isolate);
+  // The following should not crash, but return an empty handle.
+  v8::Local<v8::Context> current = v8_isolate->GetCurrentContext();
+  CHECK(current.IsEmpty());
+}
+
+
 THREADED_TEST(GetCallingContext) {
   v8::Isolate* isolate = v8::Isolate::GetCurrent();
   v8::HandleScope scope(isolate);