From f9317d65b36e31ed79939313ae90abb94f9894ab Mon Sep 17 00:00:00 2001
From: "W.C.A. Wijngaards" <wouter@nlnetlabs.nl>
Date: Mon, 12 Jun 2023 12:39:00 +0200
Subject: [PATCH] - Fix for uncertain unit test for doh buffer size events.

---
 doc/Changelog                                         |  1 +
 .../doh_downstream_buffer_size.test                   | 11 +++++++++++
 2 files changed, 12 insertions(+)

diff --git a/doc/Changelog b/doc/Changelog
index e6d323e84..7b3b65bb9 100644
--- a/doc/Changelog
+++ b/doc/Changelog
@@ -3,6 +3,7 @@
 	  directories to sys.path.
 	- Fix #895: python + sysconfig gives ANOTHER path comparing to
 	  distutils.
+	- Fix for uncertain unit test for doh buffer size events.
 
 25 May 2023: Wouter
 	- Fix unbound-dnstap-socket printout when no query is present.
diff --git a/testdata/doh_downstream_buffer_size.tdir/doh_downstream_buffer_size.test b/testdata/doh_downstream_buffer_size.tdir/doh_downstream_buffer_size.test
index bbeb9eb2b..45bde6564 100644
--- a/testdata/doh_downstream_buffer_size.tdir/doh_downstream_buffer_size.test
+++ b/testdata/doh_downstream_buffer_size.tdir/doh_downstream_buffer_size.test
@@ -23,15 +23,26 @@ if test "$?" -ne 0; then
 fi
 num=$(grep "ANSWER SEC" outfile | wc -l)
 # 58 byte answers, 500 byte max response buffer -> 8 answers
+
+# Sometimes unbound is scheduled to be able to respond very quickly,
+# before all the queries are sent, and then writes some of the queries
+# back already, emptying the buffer, which then does not overflow.
+# The attempt is to detect this test flakyness with 'mode w' write lines.
+nummodew=$(grep "mode w" unbound.log | wc -l)
+echo "num answers $num and num write events $nummodew"
 if [ $num -eq 8 ]; then
 	echo "content OK"
 else
+    if [ "(" $num -eq 9 -o $num -eq 10 ")" -a $nummodew -eq 2 ]; then
+	echo "skip buffer emptied event"
+    else
 	echo "result contents not OK"
 	echo "> cat logfiles"
 	cat outfile
 	cat unbound.log
 	echo "result contents not OK"
 	exit 1
+    fi
 fi
 echo "OK"