From 3387f33a8e7b4107f4268dec2a72a3fa943d706c Mon Sep 17 00:00:00 2001
From: Cheng Zhao <zcbenz@gmail.com>
Date: Wed, 11 Feb 2015 22:09:42 +0800
Subject: [PATCH] Check internal field before converting

---
 native_mate/wrappable.cc | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/native_mate/wrappable.cc b/native_mate/wrappable.cc
index d783306c45..fb051a8bbf 100644
--- a/native_mate/wrappable.cc
+++ b/native_mate/wrappable.cc
@@ -67,6 +67,8 @@ void* FromV8Impl(v8::Isolate* isolate, v8::Handle<v8::Value> val) {
   if (!val->IsObject())
     return NULL;
   v8::Handle<v8::Object> obj = v8::Handle<v8::Object>::Cast(val);
+  if (obj->InternalFieldCount() != 1)
+    return NULL;
   return MATE_GET_INTERNAL_FIELD_POINTER(obj, 0);
 }