Rails broken with 1.8.7 bc Symbol#to_proc

Hi,

Not sure if anyone has noticed this, but Rails doesn't startup with the 
1.8.7-preview. This is because of the native Symbol#to_proc that seems 
to have a slightly different behavior than the Ruby-implemented one.
Example:

on 1.8.6 this:
class Symbol
 def to_proc
   proc { |*args| args.shift.__send__(self, *args) }
 end
end

p([[proc{ },1]].each(&:call))

Will fail with:
t1.rb:3:in `__send__': undefined method `call' for 
[#<Proc:[e-mail]:7>, 1]:Array (NoMethodError)
        from t1.rb:3:in `to_proc'
        from t1.rb:7:in `each'
        from t1.rb:7

While with 1.8.7-preview this line
 p([[proc{ },1]].each(&:call))

will not fail, but print
[[1]]

The error Rails gives is related:
/Users/olabini/workspace/optimize_jruby/vendor/rails/activesupport/lib/active_support/inflector.rb:257:in 
`object_id': wrong number of arguments (1 for 0) (ArgumentError)
        from 
/Users/olabini/workspace/optimize_jruby/vendor/rails/activesupport/lib/active_support/inflector.rb:257:in 
`to_proc'
        from 
/Users/olabini/workspace/optimize_jruby/vendor/rails/activesupport/lib/active_support/dependencies.rb:377:in 
`collect'
        from 
/Users/olabini/workspace/optimize_jruby/vendor/rails/activesupport/lib/active_support/dependencies.rb:377:in 
`new_constants_in'
        from 
/Users/olabini/workspace/optimize_jruby/vendor/rails/activesupport/lib/active_support/dependencies.rb:496:in 
`require'
        from 
/Users/olabini/workspace/optimize_jruby/vendor/rails/activesupport/lib/active_support.rb:36
        from 
/Users/olabini/workspace/optimize_jruby/vendor/rails/railties/lib/commands/server.rb:1:in 
`require'
        from 
/Users/olabini/workspace/optimize_jruby/vendor/rails/railties/lib/commands/server.rb:1
        from script/server:3:in `require'
        from script/server:3


Cheers

-- 
 Ola Bini (http://ola-bini.blogspot.com) 
 JRuby Core Developer
 Developer, ThoughtWorks Studios (http://studios.thoughtworks.com)
 Practical JRuby on Rails (http://apress.com/book/view/9781590598818)

 "Yields falsehood when quined" yields falsehood when quined.