Fixed Mongoclient.prototype.close bug where _db was missing

Author: christkv

lib/mongodb/mongo_client.js

@@ -78,6 +78,8 @@ MongoClient.prototype.connect = function(url, options, callback) {
 
  MongoClient.connect(url, options, function(err, db) {
  if(err) return callback(err, db);
+ // Store internal db instance reference
+ self._db = db;
  // Emit open and perform callback
  self.emit("open", err, db);
  callback(err, db);
@@ -97,7 +99,6 @@ MongoClient.prototype.open = function(callback) {
  // Open the db
  this._db.open(function(err, db) {
  if(err) return callback(err, null);
-
  // Emit open event
  self.emit("open", err, db);
  // Callback