merge

# File lib/uri/generic.rb, line 1099
    def merge(oth)
      rel = parser.send(:convert_to_uri, oth)

      if rel.absolute?
        #raise BadURIError, "both URI are absolute" if absolute?
        # hmm... should return oth for usability?
        return rel
      end

      unless self.absolute?
        raise BadURIError, "both URI are relative"
      end

      base = self.dup

      authority = rel.userinfo || rel.host || rel.port

      # RFC2396, Section 5.2, 2)
      if (rel.path.nil? || rel.path.empty?) && !authority && !rel.query
        base.fragment=(rel.fragment) if rel.fragment
        return base
      end

      base.query = nil
      base.fragment=(nil)

      # RFC2396, Section 5.2, 4)
      if !authority
        base.set_path(merge_path(base.path, rel.path)) if base.path && rel.path
      else
        # RFC2396, Section 5.2, 4)
        base.set_path(rel.path) if rel.path
      end

      # RFC2396, Section 5.2, 7)
      base.set_userinfo(rel.userinfo) if rel.userinfo
      base.set_host(rel.host)         if rel.host
      base.set_port(rel.port)         if rel.port
      base.query = rel.query       if rel.query
      base.fragment=(rel.fragment) if rel.fragment

      return base
    end