prevent errors when passing a frozen string as a param to ActionController::TestCase#process

since ActionDispatch::Http::Parameters#encode_params will force encoding on all params strings (when using an encoding aware Ruby), dup all strings passed into process.  This prevents modification of params passed in and, more importantly, doesn't barf when a frozen string is passed
thanks and high fives to kinsteronline

2 files changed, 15 insertions, 1 deletions

diff --git a/actionpack/lib/action_controller/test_case.rb b/actionpack/lib/action_controller/test_case.rb
index bc4f8bb9ce..0085f542aa 100644
--- a/actionpack/lib/action_controller/test_case.rb
+++ b/actionpack/lib/action_controller/test_case.rb
@@ -147,7 +147,9 @@ module ActionController
         if value.is_a? Fixnum
           value = value.to_s
         elsif value.is_a? Array
-          value = Result.new(value)
+          value = Result.new(value.map { |v| v.is_a?(String) ? v.dup : v })
+        elsif value.is_a? String
+          value = value.dup
         end
 
         if extra_keys.include?(key.to_sym)
diff --git a/actionpack/test/controller/test_test.rb b/actionpack/test/controller/test_test.rb
index edda0d0a30..5896222a0a 100644
--- a/actionpack/test/controller/test_test.rb
+++ b/actionpack/test/controller/test_test.rb
@@ -493,6 +493,18 @@ XML
     )
   end
 
+  def test_params_passing_with_frozen_values
+    assert_nothing_raised do
+      get :test_params, :frozen => 'icy'.freeze, :frozens => ['icy'.freeze].freeze
+    end
+    parsed_params = eval(@response.body)
+    assert_equal(
+      {'controller' => 'test_test/test', 'action' => 'test_params',
+       'frozen' => 'icy', 'frozens' => ['icy']},
+      parsed_params
+    )
+  end
+
   def test_id_converted_to_string
     get :test_params, :id => 20, :foo => Object.new
     assert_kind_of String, @request.path_parameters['id']