The DIV tag generated inside form_for and form_tag by default has the style 'margin:0;padding:0' and the input fields inside it (_method and authenticity_token) are hidden, so it usually has no effect on the HTML page, but sometimes you need to have a CSS class on it to avoid some layout/float issues.
This patch adds a configuration option that can be used like this:
config.action_view.html_options_for_extra_tag_in_form = {:class=>'hideMe'}
or
config.action_view.html_options_for_extra_tag_in_form = {:class=>'hideMe', :style=>'display:none'}