From 537ad0bca3479c10fc7d1093aff534be11800dcb Mon Sep 17 00:00:00 2001
From: rl1987 <rl1987@sdf.lonestar.org>
Date: Fri, 29 Mar 2019 18:38:27 +0200
Subject: [PATCH] Check for NULL in tor_assertf_nonfatal()

---
 src/lib/log/util_bug.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/lib/log/util_bug.c b/src/lib/log/util_bug.c
index e5d5a2958c..b9dc296fc6 100644
--- a/src/lib/log/util_bug.c
+++ b/src/lib/log/util_bug.c
@@ -145,7 +145,8 @@ tor_bug_occurred_(const char *fname, unsigned int line,
     log_warn(LD_BUG, "%s:%u: %s: Non-fatal assertion %s failed.%s",
              fname, line, func, expr, once_str);
     tor_asprintf(&buf, "Non-fatal assertion %s failed in %s at %s:%u%s%s",
-                 expr, func, fname, line, fmt ? " : " : "", extra);
+                 expr, func, fname, line, fmt ? " : " : "",
+                 extra ? extra : "");
     tor_free(extra);
   }
   log_backtrace(LOG_WARN, LD_BUG, buf);