From 295dbc3055af7a6bf9d61a0a0b72f66735330a78 Mon Sep 17 00:00:00 2001
From: Aaron Eppert <aaron.eppert@packetsled.com>
Date: Mon, 26 Oct 2015 17:55:01 -0400
Subject: [PATCH] Fix for JSON formatter

In the event that the first entry in a record is optional AND not present, the serializer will incorrectly add a leading comma. This leading common is invalid JSON and will, more often than not, cause parser failures downstream.
---
 src/threading/formatters/JSON.cc | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/src/threading/formatters/JSON.cc b/src/threading/formatters/JSON.cc
index 1a2fd84c4a..3e5bfe9391 100644
--- a/src/threading/formatters/JSON.cc
+++ b/src/threading/formatters/JSON.cc
@@ -35,8 +35,14 @@ bool JSON::Describe(ODesc* desc, int num_fields, const Field* const * fields,
 		const u_char* bytes = desc->Bytes();
 		int len = desc->Len();
 
-		if ( i > 0 && len > 0 && bytes[len-1] != ',' && vals[i]->present )
-			desc->AddRaw(",");
+		if ( i > 0 && len > 0 && bytes[len-1] != ',' && vals[i]->present ) {
+			// Issue if the first value of a record is optional AND not present
+			// then an empty json field will be produced, which is invalid.
+			// - ANE - 10/26/2015
+			if (len > 1 && bytes[len-1] != '{') {
+				desc->AddRaw(",");
+			}
+		}
 
 		if ( ! Describe(desc, vals[i], fields[i]->name) )
 			return false;