just check to see that the first item in the list is an array

2 files changed, 10 insertions, 1 deletions

diff --git a/actionpack/lib/action_view/helpers/form_options_helper.rb b/actionpack/lib/action_view/helpers/form_options_helper.rb
index c677257d60..d636702111 100644
--- a/actionpack/lib/action_view/helpers/form_options_helper.rb
+++ b/actionpack/lib/action_view/helpers/form_options_helper.rb
@@ -579,7 +579,7 @@ module ActionView
       def to_select_tag(choices, options, html_options)
         selected_value = options.has_key?(:selected) ? options[:selected] : value(object)
 
-        if !choices.empty? && choices.try(:first).try(:second).respond_to?(:each)
+        if !choices.empty? && Array === choices.first
           option_tags = grouped_options_for_select(choices, :selected => selected_value, :disabled => options[:disabled])
         else
           option_tags = options_for_select(choices, :selected => selected_value, :disabled => options[:disabled])
diff --git a/actionpack/test/template/form_options_helper_test.rb b/actionpack/test/template/form_options_helper_test.rb
index 6aea991f7c..d3e0cc41a9 100644
--- a/actionpack/test/template/form_options_helper_test.rb
+++ b/actionpack/test/template/form_options_helper_test.rb
@@ -587,6 +587,15 @@ class FormOptionsHelperTest < ActionView::TestCase
     )
   end
 
+  def test_empty
+    @post = Post.new
+    @post.category = ""
+    assert_dom_equal(
+      "<select id=\"post_category\" name=\"post[category]\"><option value=\"\">Please select</option>\n<option value=\"\"></option>\n</select>",
+      select("post", "category", [], :prompt => true, :include_blank => true)
+    )
+  end
+
   def test_select_with_selected_value
     @post = Post.new
     @post.category = "<mus>"