From a3ef53574c1baa7f04e4275f4a9c48dff62c1a56 Mon Sep 17 00:00:00 2001
From: PJ Eby <pje@telecommunity.com>
Date: Wed, 25 Mar 2020 09:53:28 -0400
Subject: [PATCH] Support RFC 7505 "null MX"  (#702) (#703)

* Fix #702: Spurious null MX changes on CloudFlare

* Test roundtripping null MX on Cloudflare

* Use an if instead of TrimSuffix

* Add other providers that support RFC 7505

* Suppress test for non-compliant providers
---
 integrationTest/integration_test.go        | 5 +++++
 providers/cloudflare/cloudflareProvider.go | 4 +++-
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/integrationTest/integration_test.go b/integrationTest/integration_test.go
index f921e6af1..b25a49a27 100644
--- a/integrationTest/integration_test.go
+++ b/integrationTest/integration_test.go
@@ -609,6 +609,11 @@ func makeTests(t *testing.T) []*TestGroup {
 			tc("Record pointing to @", mx("foo", 8, "**current-domain**")),
 		),
 
+		testgroup("Null MX",
+			not("AZURE_DNS", "GANDI_V5", "NAMEDOTCOM", "DIGITALOCEAN"), // These providers don't support RFC 7505
+			tc("Null MX", mx("@", 0, ".")),
+		),
+
 		testgroup("NS",
 			not("DNSIMPLE", "EXOSCALE"),
 			// DNSIMPLE: Does not support NS records nor subdomains.
diff --git a/providers/cloudflare/cloudflareProvider.go b/providers/cloudflare/cloudflareProvider.go
index 0dc82f482..3f42de170 100644
--- a/providers/cloudflare/cloudflareProvider.go
+++ b/providers/cloudflare/cloudflareProvider.go
@@ -541,7 +541,9 @@ type cfRecord struct {
 func (c *cfRecord) nativeToRecord(domain string) *models.RecordConfig {
 	// normalize cname,mx,ns records with dots to be consistent with our config format.
 	if c.Type == "CNAME" || c.Type == "MX" || c.Type == "NS" || c.Type == "SRV" {
-		c.Content = dnsutil.AddOrigin(c.Content+".", domain)
+		if c.Content != "." {
+			c.Content = c.Content + "."
+		}
 	}
 
 	rc := &models.RecordConfig{