merge revision(s) 39725: [Backport #8054]

	* lib/resolv-replace.rb (TCPSocket#initialize): resolve the 3rd
	  argument only if non-nil value is given.
	  [ruby-dev:47150] [ruby-trunk - Bug #8054] reported and analyzed by
	  mrkn.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_0_0@40089 b2dd03c8-39d4-4d8f-98ff-823fe69b080e