Rack::Utils.parse_nested_query throws exceptions, leads to 500 errors on every Rails app

On Rails 2.3.2:

Rack::Utils.parse_nested_query('x=0&x[y]=1') IndexError: string not matched

This leads to 500 errors on any Rails app. For instance: http://rubyonrails.org?x=0&x[y]=1

I would expect "x=0&x[y]=1" to generate params['x'] == { 'y' => '1' }. This would follow Rails's "form.checkbox()" convention, in which "?x=0&x=1" leads to params['x'] == '1'.

I'm quite opinionated about Rack's being the wrong place to do parameter parsing (see http://groups.google.com/group/r... and the chutzpah Rack has to throw an exception in something as trivial as parameter parsing. (In Rack 1.0.0 the exception is accidental, but in git master it becomes explicit.)

Please stop my Rails app from generating 500 errors when users enter the wrong URL! (And, as a helpful bonus, please make "x=0&x[y]=1" generate params == "{ 'x' => { 'y' => '1' } }", so my app will work ;).)