多服务器结果选择bug

[cokebar]

ChinaDNS填入了两个国内DNS一个国外DNS，然后情况是其中一个国内DNS（isp_dns2）解析出现问题（估计是临时抽风），只有一个CNAME，没有继续往后解析到A记录：

dig +all @isp_dns2 static-resource.np.community.playstation.net

; <<>> DiG 9.12.4 <<>> +all @isp_dns2 static-resource.np.community.playstation.net
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 32276
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;static-resource.np.community.playstation.net. IN A

;; ANSWER SECTION:
static-resource.np.community.playstation.net. 2625 IN CNAME static-resource.np.community.playstation.net.edgekey.net.

另外一个国内DNS（isp_dns1）和国外DNS正常。 在这种情况下： PC端：

dig @192.168.1.1 -p 5355 static-resource.np.community.playstation.net

路由器上：

chinadns -c /etc/chinadns_chnroute.txt -b 0.0.0.0 -p 5355 -s isp_dns1,isp_dns2 ,127.0.0.1#5311 -v
Thu May 16 00:24:42 2019 request static-resource.np.community.playstation.net from isp_dns1,isp_dns2 ,127.0.0.1:5311
Thu May 16 00:24:42 2019 response static-resource.np.community.playstation.net from isp_dns1:53 - 23.51.209.94, filter
Thu May 16 00:24:42 2019 response static-resource.np.community.playstation.net from isp_dns2:53 - pass
Thu May 16 00:24:42 2019 response static-resource.np.community.playstation.net from 127.0.0.1:5311 - 23.57.113.171, pass

可以看到来自isp_dns2的不正常的结果pass了，正常的isp_dns1结果被filter了。。