Escape cookie's key and value in ActionController::TestCase

Get an incorrect cookie value in controller action method
if cookie value contains an escapable string.

actionpack/lib/action_dispatch/middleware/cookies.rb

@@ -337,7 +337,7 @@ def update_cookies_from_jar
       end
 
       def to_header
-        @cookies.map { |k,v| "#{k}=#{v}" }.join ';'
+        @cookies.map { |k,v| "#{::Rack::Utils.escape(k)}=#{::Rack::Utils.escape(v)}" }.join ';'
       end
 
       def handle_options(options) #:nodoc:

actionpack/test/controller/test_case_test.rb

@@ -137,6 +137,11 @@ def create
       head :created, location: 'created resource'
     end
 
+    def read_cookie
+      cookies["foo"]
+      render plain: 'ok'
+    end
+
     def delete_cookie
       cookies.delete("foo")
       render plain: 'ok'
@@ -825,8 +830,10 @@ def test_request_format_kwarg_overrides_params
 
   def test_should_have_knowledge_of_client_side_cookie_state_even_if_they_are_not_set
     cookies['foo'] = 'bar'
+    cookies['escape'] = '+'
     get :no_op
     assert_equal 'bar', cookies['foo']
+    assert_equal '+', cookies['escape']
   end
 
   def test_should_detect_if_cookie_is_deleted