Merge pull request #3581 from amatsuda/metal_response_body_19

AC::Metal#response_body= stores different value in Ruby 1.8 and 1.9

actionpack/lib/action_controller/metal.rb

@@ -182,7 +182,13 @@ module ActionController
     end
 
     def response_body=(val)
-      body = val.nil? ? nil : (val.respond_to?(:each) ? val : [val])
+      body = if val.is_a?(String)
+        [val]
+      elsif val.nil? || val.respond_to?(:each)
+        val
+      else
+        [val]
+      end
       super body
     end
 

actionpack/test/controller/new_base/bare_metal_test.rb

@@ -23,6 +23,12 @@ module BareMetalTest
 
       assert_equal "Hello world", string
     end
+
+    test "response_body value is wrapped in an array when the value is a String" do
+      controller = BareController.new
+      controller.index
+      assert_equal ["Hello world"], controller.response_body
+    end
   end
 
   class HeadController < ActionController::Metal