From 23c09b6bc2897ada21de220c48799f01171dcdf4 Mon Sep 17 00:00:00 2001
From: Nick Mathewson <nickm@torproject.org>
Date: Fri, 16 Dec 2016 12:21:02 -0500
Subject: [PATCH] Resolve a division-by-zero complaint from coverity. CID
 1397272

---
 src/or/entrynodes.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/or/entrynodes.c b/src/or/entrynodes.c
index 8715af7957..2e46aba02c 100644
--- a/src/or/entrynodes.c
+++ b/src/or/entrynodes.c
@@ -638,7 +638,8 @@ choose_guard_selection(const or_options_t *options,
   */
 
   static int have_warned_extreme_threshold = 0;
-  if (n_passing_filter < extreme_threshold &&
+  if (n_guards &&
+      n_passing_filter < extreme_threshold &&
       ! have_warned_extreme_threshold) {
     have_warned_extreme_threshold = 1;
     const double exclude_frac =