From fbe69ca3f8d07b7ca57d64936870dc21c9e489ce Mon Sep 17 00:00:00 2001
From: David Lin <linpeng1577@gmail.com>
Date: Mon, 10 Aug 2020 18:31:45 +0800
Subject: [PATCH] Update esp8266_tencent_firmware.c

    if (!str)
    {
        return -1;
    }
---
 devices/esp8266_tencent_firmware/esp8266_tencent_firmware.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/devices/esp8266_tencent_firmware/esp8266_tencent_firmware.c b/devices/esp8266_tencent_firmware/esp8266_tencent_firmware.c
index 505648cc..9974f9b5 100644
--- a/devices/esp8266_tencent_firmware/esp8266_tencent_firmware.c
+++ b/devices/esp8266_tencent_firmware/esp8266_tencent_firmware.c
@@ -130,6 +130,10 @@ int esp8266_tencent_firmware_module_mqtt_state_get(mqtt_state_t *state)
     }
 
     str = strstr(echo.buffer, "+TCMQTTSTATE:");
+    if (!str) 
+    {
+        return -1;
+    }
     sscanf(str, "+TCMQTTSTATE:%d", &ret_state);
     if (ret_state == 0) {
         *state = MQTT_STATE_DISCONNECTED;