Take the basename of the upload’s original filename. This handles the full Windows paths given by Internet Explorer (and perhaps other broken user agents) without affecting those which give the lone filename. The Windows regexp is adapted from Perl’s File::Basename.

Source Code

# File action_controller/request.rb, line 710
def original_filename
  unless defined? @original_filename
    @original_filename =
      unless original_path.blank?
        if original_path =~ /^(?:.*[:\\\/])?(.*)/m
          $1
        else
          File.basename original_path
        end
      end
  end
  @original_filename
end