From a7af13730ba9f0cd353cb304ce1ce54384356ab3 Mon Sep 17 00:00:00 2001
From: Maria Matejka <mq@ucw.cz>
Date: Mon, 30 Sep 2019 13:53:24 +0200
Subject: [PATCH] Testing: Don't call vsnprintf with NULL format

---
 test/birdtest.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/test/birdtest.c b/test/birdtest.c
index ede4eb527..ccd944a3c 100644
--- a/test/birdtest.c
+++ b/test/birdtest.c
@@ -202,7 +202,8 @@ bt_log_result(int result, const char *fmt, va_list argptr)
 	   (fmt && strlen(fmt) > 0) ? ": " : "");
   pos = msg_buf + strlen(msg_buf);
 
-  vsnprintf(pos, sizeof(msg_buf) - (pos - msg_buf), fmt, argptr);
+  if (fmt)
+    vsnprintf(pos, sizeof(msg_buf) - (pos - msg_buf), fmt, argptr);
 
   int chrs = 0;
   for (uint i = 0; i < strlen(msg_buf); i += get_num_terminal_cols())
-- 
2.47.2