From fc984941eeaaa35ef9a04722ffcda8e8b5076243 Mon Sep 17 00:00:00 2001
From: Julius Volz <julius.volz@gmail.com>
Date: Wed, 1 Nov 2017 09:34:40 +0000
Subject: [PATCH] nflog: Fix Log() crash when gossip is nil (#1064)

---
 nflog/nflog.go      | 8 +++++---
 nflog/nflog_test.go | 9 +++++++++
 2 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/nflog/nflog.go b/nflog/nflog.go
index 2742a1f6..4cbf121d 100644
--- a/nflog/nflog.go
+++ b/nflog/nflog.go
@@ -360,9 +360,11 @@ func (l *nlog) Log(r *pb.Receiver, gkey string, firingAlerts, resolvedAlerts []u
 		},
 		ExpiresAt: now.Add(l.retention),
 	}
-	l.gossip.GossipBroadcast(gossipData{
-		key: e,
-	})
+	if l.gossip != nil {
+		l.gossip.GossipBroadcast(gossipData{
+			key: e,
+		})
+	}
 	l.st[key] = e
 
 	return nil
diff --git a/nflog/nflog_test.go b/nflog/nflog_test.go
index c7a8f0ab..abe8dfa4 100644
--- a/nflog/nflog_test.go
+++ b/nflog/nflog_test.go
@@ -264,3 +264,12 @@ func TestGossipDataCoding(t *testing.T) {
 		require.Equal(t, in, out, "decoded data doesn't match encoded data")
 	}
 }
+
+func TestNilGossipDoesNotCrash(t *testing.T) {
+	nl, err := New()
+	if err != nil {
+		require.NoError(t, err, "constructing nflog failed")
+	}
+	err = nl.Log(&pb.Receiver{}, "key", []uint64{}, []uint64{})
+	require.NoError(t, err, "logging notification failed")
+}