Temporary fix for the extra newline (
) Rails 3.2.3 + Haml are adding to the output of the text_area form helper.

fixing_x000a.rb

module ActionView
  module Helpers
    module FormHelper
      def text_area(object_name, method, options = {})
        html = InstanceTag.new(object_name, method, self, options.delete(:object)).to_text_area_tag(options)
        html.gsub(/>\
/, '>').html_safe
      end
    end
  end
end

Oh nice. Much nicer. Mine was a WTF-knee-jerk hack. :)

Where do you put this? In /lib/action_view.rb? Rails seems to find it there on my machine, but not on Heroku.

Never mind. /config/initializers/action_view.rb is the right place for it.

FYI this will work fine for ugly mode, but in indented mode it will add spaces after the opening textarea tag.

I've opened an issue rails/rails#6236 for this.