It fixed the several bugs that was found after RDoc 6 releasing.
From: SHIBATA Hiroshi <hsbt@ruby-lang.org>
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@62924 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
When you change this to true, you may need to add more tests.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@53141 b2dd03c8-39d4-4d8f-98ff-823fe69b080e