Capture block so content won't leak.

The [following pull request](https://github.com/rails/rails/pull/8916) fixed
the block being passed to the appropriate helper method. However, the content
being passed into the block is generating repeated markup on the page due to
some weird ERb evaluation.

This commit tries to capture the block's generated output so the page isn't
flooded with markup.

[Rafael França + José Mota]

Closes #8936

1 files changed, 2 insertions, 2 deletions

diff --git a/actionpack/lib/action_view/helpers/tags/collection_check_boxes.rb b/actionpack/lib/action_view/helpers/tags/collection_check_boxes.rb
index d27df45b5a..9655008fe2 100644
--- a/actionpack/lib/action_view/helpers/tags/collection_check_boxes.rb
+++ b/actionpack/lib/action_view/helpers/tags/collection_check_boxes.rb
@@ -13,13 +13,13 @@ module ActionView
           end
         end
 
-        def render
+        def render(&block)
           rendered_collection = render_collection do |item, value, text, default_html_options|
             default_html_options[:multiple] = true
             builder = instantiate_builder(CheckBoxBuilder, item, value, text, default_html_options)
 
             if block_given?
-              yield builder
+              @template_object.capture(builder, &block)
             else
               render_component(builder)
             end