From 5b4b0791050fedec80053d11b3d566fbe0a459db Mon Sep 17 00:00:00 2001
From: "Roger A. Light" <roger@atchoo.org>
Date: Fri, 10 Jul 2020 17:10:23 +0100
Subject: [PATCH] mosquitto_pub: Print reason string on publish error, if it
 exists.

---
 client/pub_client.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/client/pub_client.c b/client/pub_client.c
index f5617d95..3af05ac3 100644
--- a/client/pub_client.c
+++ b/client/pub_client.c
@@ -185,12 +185,18 @@ void my_connect_callback(struct mosquitto *mosq, void *obj, int result, int flag
 
 void my_publish_callback(struct mosquitto *mosq, void *obj, int mid, int reason_code, const mosquitto_property *properties)
 {
+	char *reason_string = NULL;
 	UNUSED(obj);
 	UNUSED(properties);
 
 	last_mid_sent = mid;
 	if(reason_code > 127){
 		err_printf(&cfg, "Warning: Publish %d failed: %s.\n", mid, mosquitto_reason_string(reason_code));
+		mosquitto_property_read_string(properties, MQTT_PROP_REASON_STRING, &reason_string, false);
+		if(reason_string){
+			err_printf(&cfg, "%s\n", reason_string);
+			free(reason_string);
+		}
 	}
 	publish_count++;