padrino/padrino-framework — pull request #1337 by namusyaka (2013-07-07 12:12:37+00:00)
Title: Fixed :grouped_options of select_tag.

Reference to issue #1294.
When using content_tag and other tag helpers in template of erb or slim, ` __erb_in_template` is always defined.
So, I thought that concat_content(output) is executed in #content_tag, against my own will.
This pull request is way of solving without using block in #grouped_options_for_select.