From 780318c5c8ea8ac9d990f8423d7710f2500e4a6b Mon Sep 17 00:00:00 2001
From: DuckSoft <realducksoft@gmail.com>
Date: Thu, 25 Jun 2020 13:52:00 +0800
Subject: [PATCH] handle dns.PackMessage error

this will fix #2599
---
 app/dns/dohdns.go | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/app/dns/dohdns.go b/app/dns/dohdns.go
index 1c183fb6c..02b0906cf 100644
--- a/app/dns/dohdns.go
+++ b/app/dns/dohdns.go
@@ -246,7 +246,11 @@ func (s *DoHNameServer) sendQuery(ctx context.Context, domain string, option IPO
 			dnsCtx, cancel := context.WithDeadline(dnsCtx, deadline)
 			defer cancel()
 
-			b, _ := dns.PackMessage(r.msg)
+			b, err := dns.PackMessage(r.msg)
+			if err != nil {
+				newError("failed to pack dns query").Base(err).AtError().WriteToLog()
+				return
+			}
 			resp, err := s.dohHTTPSContext(dnsCtx, b.Bytes())
 			if err != nil {
 				newError("failed to retrieve response").Base(err).AtError().WriteToLog()