* lib/rexml/entity.rb (unnormalized): do not call
	  document.record_entity_expansion if document is nil.
	  see <http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=502535>.
	  Thanks, Naohisa Goto.  backported from trunk.
	* test/rexml/test_document.rb: ditto.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_8_7@22062 b2dd03c8-39d4-4d8f-98ff-823fe69b080e