From 953038f0b2a29a0201a0d278a6e64868db764f36 Mon Sep 17 00:00:00 2001
From: Jeremy Ruston <jeremy@jermolene.com>
Date: Mon, 9 Sep 2019 14:47:27 +0100
Subject: [PATCH] Don't use field indexer when looking for blank/missing fields

Fixes #4247
---
 core/modules/filters/field.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/core/modules/filters/field.js b/core/modules/filters/field.js
index 7480a87cb..fc8223555 100644
--- a/core/modules/filters/field.js
+++ b/core/modules/filters/field.js
@@ -53,7 +53,7 @@ exports.field = function(source,operator,options) {
 				}
 			});
 		} else {
-			if(source.byField) {
+			if(source.byField && operator.operand) {
 				indexedResults = source.byField(fieldname,operator.operand);
 				if(indexedResults) {
 					return indexedResults