From 2e7f80d5f4e8b56f060516f71f13590593b1d876 Mon Sep 17 00:00:00 2001
From: Nick Mathewson <nickm@torproject.org>
Date: Wed, 13 Mar 2019 15:54:26 -0400
Subject: [PATCH] pubsub_check.c: Stop accepting NULL prefix, which we never
 send.

(Our code to handle it was broken, too)
---
 src/lib/pubsub/pubsub_check.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/src/lib/pubsub/pubsub_check.c b/src/lib/pubsub/pubsub_check.c
index 1b3853d8bb..e87c347c45 100644
--- a/src/lib/pubsub/pubsub_check.c
+++ b/src/lib/pubsub/pubsub_check.c
@@ -155,8 +155,7 @@ format_flags(unsigned flags)
 static void
 pubsub_cfg_dump(const pubsub_cfg_t *cfg, int severity, const char *prefix)
 {
-  if (!prefix)
-    prefix = 0;
+  tor_assert(prefix);
 
   tor_log(severity, LD_MESG,
           "%s%s %s: %s{%s} on %s (%s) <%u %u %u %u %x> [%s:%d]",