[Rails] Safely persisting query parameters in Rails 3.1

I'm working on a project (Active Admin) that needs to be able to build
links on the page (e.g. pagination) that include arbitrary query parameters
that the user has entered.

Since `url_for` symbolizes any keys passed to it, for obvious memory
concerns you can't just pass the entire params hash.

In Rails 3.2, however, you can do this:

include Rails.application.routes.url_helpersurl_for action: 'index', controller: 'employees', host: 'foo.bar', params: {'eee' => 3}# => "http://foo.bar/employees?eee=3"Symbol.all_symbols.map(&:to_s).include? 'eee'# => false


In other words, you can pass `params: request.query_parameters` to
`url_for` to avoid the potential DOS issue.

However we still support Rails 3.0 and 3.1, and they completely ignore
`:params`.

Save for monkeypatching, has anyone found a way to safely provide this
functionality?

Thanks,
Sean Linsley