(merged partially from r42927)
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_0_0@45100 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
(merged partially from r42927)
requires. [ruby-core:58918] [Backport #9224]
see also https://github.com/rubygems/rubygems/pull/833
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_0_0@45100 b2dd03c8-39d4-4d8f-98ff-823fe69b080e