causes test failures introduced at r55376.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@55381 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

* lib/forwardable.rb (_delegator_method): remove __send__ call if
  possible, so that more optimizations will be enabled.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@55376 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

* lib/forwardable.rb (_delegator_method): leave the backtrace
  untouched during accessor.  forwardable.rb does not appear in
  the backtrace during delegated method because of tail-call
  optimization.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@55372 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@55368 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

* lib/forwardable.rb (Forwardable._delegator_method): extract
  method generator and deal with non-module objects.
  [ruby-dev:49656] [Bug #12478]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@55366 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

  r53381 changed to accept only Symbol or String for accessors, but
  there are several rubygems that pass classes (e.g. Array,
  Hash, ...) as accessors. Prior r53381, it was accepted because Class#to_s
  returns its class name. After r53381 given accessors are checked
  with define_method, but it accepts only Symbol or String, otherwise
  raises TypeError.

      def_delegator Foo, :some_method

  This change is to revert unwanted incompatibility. But this behavior
  may change in the future.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@53511 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

* lib/forwardable.rb (def_instance_delegator): adjust backtrace of
  method body by tail call optimization.  adjusting the delegated
  target is still done by deleting backtrace.
* lib/forwardable.rb (def_single_delegator): ditto.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@53383 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

* lib/forwardable.rb (def_instance_delegator) fix delegating to
  'args' and 'block', clashing with local variables in generated
  methods.  [ruby-core:72579] [Bug #11916]

* lib/forwardable.rb (def_single_delegator): ditto.

If you have a class that uses Forwardable to delegate a method to
another object, and the method that returns the delegate object is
called `args` or `block`, then Forwardable will fail to work.

Here's a simple example:

    class ModelCreator
      extend Forwardable

      attr_reader :args

      def_delegator :args, :model_name

      def initialize(args)
        @args = args
      end
    end

    ModelCreator.new.model_name

If you run the last line above, then you'll get:

    NoMethodError: undefined method `model_name' for []:Array

This error occurs because `def_delegator` -- as it is written in Ruby --
uses metaprogramming to add methods to the class that will then delegate
to the delegate object. So it's as if we had written:

    class ModelCreator
      extend Forwardable

      attr_reader :args

      def model_name(*args, &block)
        args.model_name(*args, &block)
      end

      def initialize(args)
        @args = args
      end
    end

As you can see, `def_delegator` will not only forward the method call
onto the delegate object, it will also forward any arguments provided as
well. It is here that the bug arises: it splats all of the arguments
into a variable which is called `args`, and because of how variable
scope works in Ruby, it then attempts to call `model_name` on *this*
variable and *not* our delegate object method.

The fix is to call the delegate object method manually using `__send__`.
(This assumes, of course, that the given receiver is, in fact, the name
of a method and not the name of an instance variable, which is also a
possibility.) We use `__send__` because the delegate object method could
be private.

So, that looks like this:

    def model_name(*args, &block)
      __send__(:args).model_name(*args, &block)
    end

Because `def_delegators` and `delegate` use `def_delegator` internally,
they also get this fix as well.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@53381 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

When you change this to true, you may need to add more tests.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@53141 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

* lib/forwardable.rb (def_instance_delegator, def_single_delegator):
  match backtraces against ::Forwardable in case the target class
  is a subclass of BasicObject and does not include Kernel.
  [ruby-core:71176] [Bug #11616]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@52259 b2dd03c8-39d4-4d8f-98ff-823fe69b080e