From c3035df5be651fa9601b7673843bac2bb407e493 Mon Sep 17 00:00:00 2001
From: gVisor bot <gvisor-bot@google.com>
Date: Fri, 15 Jul 2022 21:54:57 +0800
Subject: [PATCH] fix: DoH retry HTTP/3

---
 dns/doh.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/dns/doh.go b/dns/doh.go
index ad889ab1..ca5b655c 100644
--- a/dns/doh.go
+++ b/dns/doh.go
@@ -172,7 +172,7 @@ func (doh *dohTransport) RoundTrip(req *http.Request) (*http.Response, error) {
 	var h3Err bool
 	var fallbackErr bool
 	defer func() {
-		if doh.preferH3 && h3Err {
+		if doh.preferH3 && (h3Err || fallbackErr) {
 			doh.canUseH3.Store(doh.preferH3 && fallbackErr)
 		}
 	}()