Mark the result of grouped_options_for_select as HTML safe [#4322 state:committed]

Signed-off-by: Xavier Noria <fxn@hashref.com>

actionpack/lib/action_view/helpers/form_options_helper.rb

@@ -444,7 +444,7 @@ module ActionView
           body << content_tag(:optgroup, options_for_select(group[1], selected_key), :label => group[0])
         end
 
-        body
+        body.html_safe
       end
 
       # Returns a string of option tags for pretty much any time zone in the

actionpack/test/template/form_options_helper_test.rb

@@ -207,6 +207,10 @@ class FormOptionsHelperTest < ActionView::TestCase
     )
   end
 
+  def test_grouped_options_for_select_returns_html_safe_string
+    assert grouped_options_for_select([["Hats", ["Baseball Cap","Cowboy Hat"]]]).html_safe?
+  end
+
   def test_optgroups_with_with_options_with_hash
     assert_dom_equal(
        "<optgroup label=\"Europe\"><option value=\"Denmark\">Denmark</option>\n<option value=\"Germany\">Germany</option></optgroup><optgroup label=\"North America\"><option value=\"United States\">United States</option>\n<option value=\"Canada\">Canada</option></optgroup>",