From 71a93ed6b19fc876d4994110222b176a40f2d5ec Mon Sep 17 00:00:00 2001
From: Greg Linton <g2linton@gmail.com>
Date: Thu, 5 Jul 2018 18:02:05 -0600
Subject: [PATCH] Revert regex processor to allow empty values

---
 plugins/processors/regex/regex.go      | 6 +++---
 plugins/processors/regex/regex_test.go | 5 +++--
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/plugins/processors/regex/regex.go b/plugins/processors/regex/regex.go
index a25f33e72..9112ddd2d 100644
--- a/plugins/processors/regex/regex.go
+++ b/plugins/processors/regex/regex.go
@@ -68,7 +68,7 @@ func (r *Regex) Apply(in ...telegraf.Metric) []telegraf.Metric {
 		for _, converter := range r.Tags {
 			if value, ok := metric.GetTag(converter.Key); ok {
 				k, v := r.convert(converter, value)
-				if k != "" && v != "" {
+				if k != "" {
 					metric.AddTag(k, v)
 				}
 			}
@@ -78,8 +78,8 @@ func (r *Regex) Apply(in ...telegraf.Metric) []telegraf.Metric {
 			if value, ok := metric.GetField(converter.Key); ok {
 				switch value := value.(type) {
 				case string:
-					k, v := r.convert(converter, value)
-					if k != "" && v != "" {
+					k, _ := r.convert(converter, value)
+					if k != "" {
 						metric.AddField(r.convert(converter, value))
 					}
 				}
diff --git a/plugins/processors/regex/regex_test.go b/plugins/processors/regex/regex_test.go
index 723754cad..e7c15e5aa 100644
--- a/plugins/processors/regex/regex_test.go
+++ b/plugins/processors/regex/regex_test.go
@@ -222,7 +222,7 @@ func TestNoMatches(t *testing.T) {
 			},
 		},
 		{
-			message: "Shouldn't emit empty string when result_key given but regex doesn't match",
+			message: "Should emit empty string when result_key given but regex doesn't match",
 			converter: converter{
 				Key:         "request",
 				Pattern:     "not_match",
@@ -230,7 +230,8 @@ func TestNoMatches(t *testing.T) {
 				ResultKey:   "new_field",
 			},
 			expectedFields: map[string]interface{}{
-				"request": "/users/42/",
+				"request":   "/users/42/",
+				"new_field": "",
 			},
 		},
 	}