Make content_tag_for work without block

This is version of #8640 for master

actionpack/CHANGELOG.md

@@ -1,5 +1,9 @@
 ## Rails 4.0.0 (unreleased) ##
 
+*   Fix a bug in `content_tag_for` that prevents it for work without a block.
+
+    *Jasl*
+
 *   Change the stylesheet of exception pages for development mode.
     Additionally display also the line of code and fragment that raised
     the exception in all exceptions pages.

actionpack/lib/action_view/helpers/record_tag_helper.rb

@@ -95,7 +95,11 @@ def content_tag_for_single_record(tag_name, record, prefix, options, &block)
           options[:class] = "#{dom_class(record, prefix)} #{options[:class]}".rstrip
           options[:id]    = dom_id(record, prefix)
 
-          content_tag(tag_name, capture(record, &block), options)
+          if block_given?
+            content_tag(tag_name, capture(record, &block), options)
+          else
+            content_tag(tag_name, "", options)
+          end
         end
     end
   end

actionpack/test/template/record_tag_helper_test.rb

@@ -75,6 +75,14 @@ def test_content_tag_for_collection
     assert_dom_equal expected, actual
   end
 
+  def test_content_tag_for_collection_without_given_block
+    post_1 = RecordTagPost.new.tap { |post| post.id = 101; post.body = "Hello!" }
+    post_2 = RecordTagPost.new.tap { |post| post.id = 102; post.body = "World!" }
+    expected = %(<li class="record_tag_post" id="record_tag_post_101"></li>\n<li class="record_tag_post" id="record_tag_post_102"></li>)
+    actual = content_tag_for(:li, [post_1, post_2])
+    assert_dom_equal expected, actual
+  end
+
   def test_div_for_collection
     post_1 = RecordTagPost.new { |post| post.id = 101; post.body = "Hello!" }
     post_2 = RecordTagPost.new { |post| post.id = 102; post.body = "World!" }