mperham/sidekiq — pull request #135 by matthewford (2012-04-17 00:05:30+00:00)
Title: If no content is returned, Rack throws an error:

/Users/matt/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/rack-1.4.1/lib/rack/lint.rb: in assert, line 19
/Users/matt/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/rack-1.4.1/lib/rack/lint.rb: in check_content_type