merge revision(s) 33266:
* thread.c (rb_fd_rcopy): added an argument guard. Patch by NAKAMURA Usaku. [Bug #5306] [ruby-core:39435]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_3@33268 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
merge revision(s) 33266:
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_3@33268 b2dd03c8-39d4-4d8f-98ff-823fe69b080e