rails/rails — pull request #9216 by robertomiranda (2013-02-07 22:44:08+00:00)
Title: Activer Record:  Change behaviour with empty array in where clause

Currently the SQL generated when is passed an array empty isn't make sense

For example:
```ruby
User.where(token: []) => SELECT * from users WHERE token IN (NULL)
```
Instead generate a wrong SQL statement this patch Raise an ActiveRecord::StatementInvalid