We cannot dup on nil.

[arunagw]

Added in previous commit.

We cannot dup on nil. First we will check then do the dup

fixed failing test

  1) Error:
test_ensure_url_for_works_as_expected_when_called_with_no_options_if_default_url_options_is_not_set(EmptyUrlOptionsTest):
TypeError: can't dup NilClass
    /Users/arun/checkouts/rails/actionpack/lib/action_dispatch/routing/url_for.rb:143:in `dup'
    /Users/arun/checkouts/rails/actionpack/lib/action_dispatch/routing/url_for.rb:143:in `url_for'
    /Users/arun/checkouts/rails/actionpack/test/controller/base_test.rb:289:in `test_ensure_url_for_works_as_expected_when_called_with_no_options_if_default_url_options_is_not_set'
    /Users/arun/checkouts/rails/bundle/ruby/1.9.1/gems/mocha-0.9.12/lib/mocha/integration/mini_test/version_142_to_172.rb:27:in `run'
    /Users/arun/checkouts/rails/activesupport/lib/active_support/testing/setup_and_teardown.rb:35:in `block in run'
    /Users/arun/checkouts/rails/activesupport/lib/active_support/callbacks.rb:426:in `_run_setup_callbacks'
    /Users/arun/checkouts/rails/activesupport/lib/active_support/callbacks.rb:81:in `run_callbacks'
    /Users/arun/checkouts/rails/activesupport/lib/active_support/testing/setup_and_teardown.rb:34:in `run'

[arunagw]

I think we can just don't need to call reverse_merge! here. Test passed!!!