Merge branch 'master' of git@github.com:rails/rails

2 files changed, 12 insertions, 1 deletions

diff --git a/actionpack/lib/action_controller/base/render.rb b/actionpack/lib/action_controller/base/render.rb
index 4286577ec5..cc0d878e01 100644
--- a/actionpack/lib/action_controller/base/render.rb
+++ b/actionpack/lib/action_controller/base/render.rb
@@ -253,7 +253,8 @@ module ActionController
         response.content_type ||= Mime::JS
         render_for_text(js)
 
-      elsif json = options[:json]
+      elsif options.include?(:json)
+        json = options[:json]
         json = ActiveSupport::JSON.encode(json) unless json.respond_to?(:to_str)
         json = "#{options[:callback]}(#{json})" unless options[:callback].blank?
         response.content_type ||= Mime::JSON
diff --git a/actionpack/test/controller/render_test.rb b/actionpack/test/controller/render_test.rb
index da063710a9..023bf0eeaa 100644
--- a/actionpack/test/controller/render_test.rb
+++ b/actionpack/test/controller/render_test.rb
@@ -194,6 +194,10 @@ class TestController < ActionController::Base
     render :inline =>  "<%= controller_name %>"
   end
 
+  def render_json_nil
+    render :json => nil
+  end
+
   def render_json_hello_world
     render :json => ActiveSupport::JSON.encode(:hello => 'world')
   end
@@ -874,6 +878,12 @@ class RenderTest < ActionController::TestCase
     assert_equal "The secret is in the sauce\n", @response.body
   end
 
+  def test_render_json_nil
+    get :render_json_nil
+    assert_equal 'null', @response.body
+    assert_equal 'application/json', @response.content_type
+  end
+
   def test_render_json
     get :render_json_hello_world
     assert_equal '{"hello":"world"}', @response.body