From 1f21a0a394a2d8a41201a20ea6869530e94c379d Mon Sep 17 00:00:00 2001
From: Remi Gacogne <remi.gacogne@powerdns.com>
Date: Wed, 3 May 2023 16:37:36 +0200
Subject: [PATCH] dnsdist: check that the UDP responder thread is running after
 reconnecting

(cherry picked from commit bb1ace1fedca0f6bdd2a962514cd5a6491f3c703)
---
 pdns/dnsdistdist/dnsdist-backend.cc | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/pdns/dnsdistdist/dnsdist-backend.cc b/pdns/dnsdistdist/dnsdist-backend.cc
index 40e7033ac9..97cd0e46ec 100644
--- a/pdns/dnsdistdist/dnsdist-backend.cc
+++ b/pdns/dnsdistdist/dnsdist-backend.cc
@@ -120,6 +120,12 @@ bool DownstreamState::reconnect(bool initialAttempt)
   if (connected) {
     tl.unlock();
     d_connectedWait.notify_all();
+    if (!initialAttempt) {
+      /* we need to be careful not to start this
+         thread too soon, as the creation should only
+         happen after the configuration has been parsed */
+      start();
+    }
   }
 
   return connected;
@@ -774,7 +780,6 @@ void DownstreamState::submitHealthCheckResult(bool initial, bool newResult)
 
     if (newState && !isTCPOnly() && (!connected || d_config.reconnectOnUp)) {
       newState = reconnect();
-      start();
     }
 
     setUpStatus(newState);
-- 
2.47.2