# File lib/uri/generic.rb, line 725
    def merge(oth)
      begin
        base, rel = merge0(oth)
      rescue
        raise $!.class, $!.message
      end

      if base == rel
        return base
      end

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

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

      base.set_query(nil)
      base.set_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.set_query(rel.query)       if rel.query
      base.set_fragment(rel.fragment) if rel.fragment

      return base
    end