LearnBoost/mongoose — pull request #1436 by Prinzhorn (2013-04-17 09:43:39+00:00)
Title: When calling populate inside a pre save hook a copy of the referenced document is saved inline

This just bite me.

What I usually get when saving

```js
{
_id: ObjectId(...),
_creator: ObjectId(...)
}
```

What I get when calling `populate` inside a pre save hook

```js
{
_id: ObjectId(...),
_creator: {
/*All properties of the User are now here. No reference.*/
}
}
```