Fixes optimised named routes generating question mark followed by nothing when...

Fixes optimised named routes generating question mark followed by nothing when provided an empty hash as the last argument.
Signed-off-by: NMichael Koziarski <michael@koziarski.com>
[#481 state:committed]

actionpack/lib/action_controller/routing/optimisations.rb

@@ -103,9 +103,10 @@ def guard_condition
         end
 
         # This case uses almost the same code as positional arguments,
-        # but add an args.last.to_query on the end
+        # but add a question mark and args.last.to_query on the end,
+        # unless the last arg is empty
         def generation_code
-          super.insert(-2, '?#{args.last.to_query}')
+          super.insert(-2, '#{\'?\' + args.last.to_query unless args.last.empty?}')
         end
 
         # To avoid generating "http://localhost/?host=foo.example.com" we

actionpack/test/controller/routing_test.rb

@@ -1694,6 +1694,12 @@ def test_named_route_url_method_with_ordered_parameters_and_hash
         controller.send(:multi_url, 7, "hello", 5, :baz => "bar")
     end
 
+    def test_named_route_url_method_with_ordered_parameters_and_empty_hash
+      controller = setup_named_route_test
+      assert_equal "http://named.route.test/people/go/7/hello/joe/5",
+        controller.send(:multi_url, 7, "hello", 5, {})
+    end
+
     def test_named_route_url_method_with_no_positional_arguments
       controller = setup_named_route_test
       assert_equal "http://named.route.test/people?baz=bar",