Fix for ArgumentError: invalid byte sequence in UTF-8

rails_routing_invalid_chars_fix.rb

require 'action_dispatch/routing/route_set'
# Based on https://gist.github.com/2830082
module ActionDispatch
  module Routing
    class RouteSet
      class Dispatcher
        def call_with_invalid_char_handling(env)
          uri = CGI::unescape(env["REQUEST_URI"].force_encoding("UTF-8"))
          # If anything in the REQUEST_URI has an invalid encoding, then raise since it's likely to trigger errors further on.
          return [400, {'X-Cascade' => 'pass'}, []] if uri.is_a?(String) and !uri.valid_encoding?
          call_without_invalid_char_handling(env)
        end

        alias_method_chain :call, :invalid_char_handling
      end
    end
  end
end

tried this with rails 3.2.11 and when it gets to line 8 there is no REQUEST_URI param.

@radixhound That would be weird. I am using 3.2.11 but REQUEST_URI is there. Or you can try "ORIGINAL_FULLPATH" instead?