update ota

services/emqx-agent/agent.go

@@ -326,8 +326,13 @@ func (a *Access) chunkUpgrade(params rpcs.ChunkUpgrade) error {
 	if stop >= len(fileReply.File) {
 		stop = len(fileReply.File)
 	}
+	if stop < start {
+		start = stop
+	}
 	server.Log.Infof("文件截取位置------: start:%d,stop:%d", start, stop)
+
 	data := fileReply.File[start:stop]
+
 	buf.Write(gbinary.BeEncodeUint16(gconv.Uint16(len(data))))
 	buf.Write(data)
 	server.Log.Infof("1----------填充文件：%2X", buf.Bytes())