title: changing password with authlogic - validation not catching blank inputs
body: <p>I am trying to create a form to allow users to change their password:</p>
  
  <p><strong>View:</strong></p>
  
  <pre><code>- form_tag change_password_users_path do
  
    = error_messages_for :user, :header_message =&gt; "Please Try Again", :message =&gt; "We had some problems updating your account" 
    %br
  
    = label_tag :password, "New password:"
    = password_field_tag "password"
    %br
  
    = label_tag :password_confirmation, "NConfirm new password:"
    = password_field_tag "password_confirmation"
    %br
  
    = submit_tag "Update Account"
  </code></pre>
  
  <p><strong>Controller:</strong></p>
  
  <pre><code>def change_password
    @user = current_user
    if request.post?
      @user.password = params[:password]
      @user.password_confirmation = params[:password_confirmation]
      if @user.save
        redirect_to user_path(current_user)
      else
        render :action =&gt; "change_password"
      end        
    end
  end
  </code></pre>
  
  <p>Authlogic is catching validation errors when the password is 'too short' or the password doesn't match the confirmation, but doesn't do anything when the form is submitted with both fields blank.
  @user.save must be returning true, because I am redirected to 'user_path(current_user)'.</p>
  
  <p>The password is not actually changed in the database.</p>
  
  <p>Thanks for your help.</p>