merges r20147 from trunk into trunk.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_1@20195 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
merges r20147 from trunk into trunk.
from Brian Candler <B.Candler at pobox.com> in [ruby-core:12020].
[ruby-core:19713]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_1@20195 b2dd03c8-39d4-4d8f-98ff-823fe69b080e