From 89a5e21e4d9765ba1339c20af8fbb48653506800 Mon Sep 17 00:00:00 2001
From: Miroslav Lichvar <mlichvar@redhat.com>
Date: Wed, 1 Dec 2021 09:14:34 +0100
Subject: [PATCH] reference: check for unset leap_when in is_leap_close()

Check that the leap_when variable is set before testing a timestamp for
being close to a leap second. This allows the first measurement to be
accepted if starting at the Unix epoch (e.g. in a test).
---
 reference.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/reference.c b/reference.c
index bf30991..9032323 100644
--- a/reference.c
+++ b/reference.c
@@ -1333,7 +1333,8 @@ REF_DisableLocal(void)
 static int
 is_leap_close(time_t t)
 {
-  return t >= leap_when - LEAP_SECOND_CLOSE && t < leap_when + LEAP_SECOND_CLOSE;
+  return leap_when != 0 &&
+         t >= leap_when - LEAP_SECOND_CLOSE && t < leap_when + LEAP_SECOND_CLOSE;
 }
 
 /* ================================================== */