git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_2@27832 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
merges r27737 from trunk into ruby_1_9_2.¶
because ENV may change the behavior of Rake::TaskArguments.
[ruby-core:29984]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_2@27832 b2dd03c8-39d4-4d8f-98ff-823fe69b080e