Treat NULL reference case [Bug #13566]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@58769 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Treat NULL reference case [Bug #13566]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@58769 b2dd03c8-39d4-4d8f-98ff-823fe69b080e