Rails 3.2 Omniauth Devise - Add password - Skip cu

I'm using Omniauth to allow users to sign in (and create an account) through Facebook, Twitter, and Google.

However, if a user decides to not use those services anymore, but continue to use their account, they will want to add a password.

How can I let a user add a password to their account without entering a current password?*

When I let a user go to the edit_user_registration_path(@user), they see the form below:

= form_for(resource, as: resource_name, url: registration_path(resource_name), html: { method: :put, name: 'validation'}) do |f|
  = devise_error_messages!

  = f.label :email, class: 'block'
  = f.email_field :email, class: 'large'
  %span.infobar Keep this here unless you'd like to change your email

  = f.label :password, class: 'block'
  = f.password_field :password, class: 'large'
  %span.infobar Leave blank if you don't want to change it

  = f.label :password_confirmation, class: 'block'
  = f.password_field :password_confirmation, class: 'large'

  - if @user.password_required?
    = f.label :current_password, class: 'block'
    = f.password_field :current_password, class: 'large'
    %span.infobar We need your current password to confirm changes

  = f.submit "Update"

user.rb

def password_required?
  (authentications.empty? || !password.blank?) && super
end

As you can see, I have it so that if @user.password_required?, then show the current password field. Even though this field is not displayed when attempting to create a new password for the account, the form will not validate correctly, as a current password is required.

I just overwrote the RegistrationsController#update method:

class RegistrationsController < Devise::RegistrationsController
  def update
    # Override Devise to use update_attributes instead of update_with_password.
    # This is the only change we make.
    if resource.update_attributes(params[resource_name])
      set_flash_message :notice, :updated
      # Line below required if using Devise >= 1.2.0
      sign_in resource_name, resource, :bypass => true
      redirect_to after_update_path_for(resource)
    else
      clean_up_passwords(resource)
      render_with_scope :edit
    end
  end
end

Source: How To: Allow users to edit their account without providing a password