From b5bf5d3adb5ce407fafde80af7fd7a4bd82bb90a Mon Sep 17 00:00:00 2001
From: JimMoen <LnJimMoen@outlook.com>
Date: Tue, 13 Sep 2022 18:29:32 +0800
Subject: [PATCH] fix: mqtt bridge payload default value

---
 CHANGES-5.0.md                                              | 1 +
 apps/emqx_connector/src/mqtt/emqx_connector_mqtt_schema.erl | 4 ++--
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/CHANGES-5.0.md b/CHANGES-5.0.md
index 6d80240de..42fdf862c 100644
--- a/CHANGES-5.0.md
+++ b/CHANGES-5.0.md
@@ -13,6 +13,7 @@
 * Fix that redis authn will deny the unknown users [#8934](https://github.com/emqx/emqx/pull/8934)
 * Fix ExProto UDP client keepalive checking error.
   This causes the clients to not expire as long as a new UDP packet arrives [#8866](https://github.com/emqx/emqx/pull/8866)
+* Fix that MQTT Bridge message payload could be empty string. [#8949](https://github.com/emqx/emqx/pull/8949)
 
 ## Enhancements
 
diff --git a/apps/emqx_connector/src/mqtt/emqx_connector_mqtt_schema.erl b/apps/emqx_connector/src/mqtt/emqx_connector_mqtt_schema.erl
index 438f33b5d..3e683f5fb 100644
--- a/apps/emqx_connector/src/mqtt/emqx_connector_mqtt_schema.erl
+++ b/apps/emqx_connector/src/mqtt/emqx_connector_mqtt_schema.erl
@@ -177,7 +177,7 @@ fields("ingress") ->
             sc(
                 binary(),
                 #{
-                    default => <<"${payload}">>,
+                    default => undefined,
                     desc => ?DESC("payload")
                 }
             )}
@@ -224,7 +224,7 @@ fields("egress") ->
             sc(
                 binary(),
                 #{
-                    default => <<"${payload}">>,
+                    default => undefined,
                     desc => ?DESC("payload")
                 }
             )}