Sanitized the id generated by text_area_tag helper method....

Sanitized the id generated by text_area_tag helper method. text_area_tag('item[description]') should return: <textarea id="item_description" name="item[description]"></textarea> instead of: <textarea id="item[description]" name="item[description]"></textarea> The old id was causing HTML validation failures.
Signed-off-by: NMichael Koziarski <michael@koziarski.com>

actionpack/lib/action_view/helpers/form_tag_helper.rb

@@ -258,7 +258,7 @@ def text_area_tag(name, content = nil, options = {})
           options["cols"], options["rows"] = size.split("x") if size.respond_to?(:split)
         end
 
-        content_tag :textarea, content, { "name" => name, "id" => name }.update(options.stringify_keys)
+        content_tag :textarea, content, { "name" => name, "id" => sanitize_to_id(name) }.update(options.stringify_keys)
       end
 
       # Creates a check box form input tag.

actionpack/test/template/form_tag_helper_test.rb

@@ -154,6 +154,11 @@ def test_text_area_tag_should_disregard_size_if_its_given_as_an_integer
     assert_dom_equal expected, actual
   end
 
+  def test_text_area_tag_id_sanitized
+    input_elem = root_elem(text_area_tag("item[][description]"))
+    assert_match VALID_HTML_ID, input_elem['id']
+  end
+
   def test_text_field_tag
     actual = text_field_tag "title", "Hello!"
     expected = %(<input id="title" name="title" type="text" value="Hello!" />)