Why does devise me redirect me to /users instead of /users/edit when my account update fails?

The problem is like this:

If I use the default registration controller I get redirected:

• /users/edit to root when user update succeeds
• /users/edit to /users when update fails

Because the default controller update action looks like this:

if resource_updated
  sign_in resource_name, resource, bypass: true
  respond_with resource, location: after_update_path_for(resource)
else
  clean_up_passwords resource
  respond_with resource
end

after_update_path_for is set by default to root

If update fails I get the devise error messages and hasError div wrappers for the fields with error

In my registrations controller in the edit action I attribute values to a variable @myvar={2, 3}

This variable is used in the registrations_edit view

Whenever user update fails I get error no method .each for nil for my @myvar

How should I declare my view variables such that they are accessible even when update form fails?!

I have tried:

Forcing the controller to redirect to edit view no matter what:

if resource_updated
  sign_in resource_name, resource, bypass: true
  redirect_to edit_user_registration_path
else
  clean_up_passwords resource
  redirect_to edit_user_registration_path
end

This created problems because devise validations do not work anymore

Edit-------

My registrations edit:

def edit
  @images = Dir.glob("public/assets/images/users/#{current_user.id}/med/*")
end

My view:

<% img_paths = Array.new %>
  <% @images.each do |image| %>
  <%img_paths.push([
    '',
    "/assets/images/users/#{current_user.id}/original/#{image.split('/').last}",
    {'data-img-src'=>"/assets/images/users/#{current_user.id}/med/#{image.split('/').last}"}
    ])%>
  <% end %>

Edit-----

Registration controller:

class Users::RegistrationsController < Devise::RegistrationsController

  def edit
    @images = Dir.glob("public/assets/images/users/#{current_user.id}/med/*")
  end

  def update
    if params[:image_file_path]
      ff = File.open("public/"+params[:image_file_path])
      resource.image = ff
      resource.save!
    end
    self.resource = resource_class.to_adapter.get!(send(:"current_#{resource_name}").to_key)
    prev_unconfirmed_email = resource.unconfirmed_email if resource.respond_to?(:unconfirmed_email)

    resource_updated = resource.update_with_password(account_update_params)
    yield resource if block_given?
    if resource_updated
      if is_flashing_format?
        flash_key = update_needs_confirmation?(resource, prev_unconfirmed_email) ?
          :update_needs_confirmation : :updated
        set_flash_message :notice, flash_key
      end
      sign_in resource_name, resource, bypass: true
      respond_with resource, location: after_update_path_for(resource)
    else
      clean_up_passwords resource
      respond_with resource
    end
  end


  private

  def sign_up_params
    params.require(:user).permit(:first_name, :last_name, :email, :password, :password_confirmation, :telephone, :image, :address, :birthday)
  end

  def account_update_params
    params.require(:user).permit(:first_name, :last_name, :email, :password, :password_confirmation, :telephone, :image, :image_file_path, :address, :birthday)
  end

  protected 

  def update_resource(resource, params)
    resource.update_without_password(params)
  end

  def after_update_path_for(resource)
    edit_user_registration_path
  end

end