Fix mosquitto_pub exiting with error code 0 when an error occurred.

Thanks to janniswarnat.

Closes #1285.

ChangeLog.txt

@@ -15,6 +15,8 @@ Clients:
 - Fix -L url parsing when `/topic` part is missing.
 - Stop some error messages being printed even when `--quiet` was used.
   Closes #1284.
+- Fix mosquitto_pub exiting with error code 0 when an error occurred.
+  Closes #1285.
 
 
 1.6.2 - 20190430

client/pub_client.c

@@ -312,7 +312,7 @@ int pub_shared_loop(struct mosquitto *mosq)
 	if(mode == MSGMODE_STDIN_LINE){
 		mosquitto_loop_stop(mosq, false);
 	}
-	return 0;
+	return rc;
 }