read_with_substitution

# File lib/rexml/text.rb, line 334
    def Text::read_with_substitution( input, illegal=nil )
      copy = input.clone

      if copy =~ illegal
        raise ParseException.new( "malformed text: Illegal character #$& in \"#{copy}\"" )
      end if illegal

      copy.gsub!( /\r\n?/, "\n" )
      if copy.include? &&
        copy.gsub!( SETUTITSBUS[0], SLAICEPS[0] )
        copy.gsub!( SETUTITSBUS[1], SLAICEPS[1] )
        copy.gsub!( SETUTITSBUS[2], SLAICEPS[2] )
        copy.gsub!( SETUTITSBUS[3], SLAICEPS[3] )
        copy.gsub!( SETUTITSBUS[4], SLAICEPS[4] )
        copy.gsub!( /&#0*((?:\d+)|(?:x[a-f0-9]+));/ ) {
          m=$1
          #m='0' if m==''
          m = "0#{m}" if m[0] == xx
          [Integer(m)].pack('U*')
        }
      end
      copy
    end