diff --git a/tools/robot/clientnet.js b/tools/robot/clientnet.js
index 02300a25..ed1e1d16 100644
--- a/tools/robot/clientnet.js
+++ b/tools/robot/clientnet.js
@@ -94,11 +94,12 @@ class ClientNet {
 
   async onParsePacket() {
     let offset = 0;
-    while (this.recvBuf.length > offset + 12) {
+    while (this.recvBuf.length >= offset + 12) {
       const msgSize = this.recvBuf.readUInt16LE(offset + 0);
       const msgId = this.recvBuf.readUInt16LE(offset + 2);
       const seqId = this.recvBuf.readUInt32LE(offset + 4);
       const magicCode = this.recvBuf.readUInt16LE(offset + 8);
+      //console.log('onParsePacket', msgSize, msgId, seqId, magicCode);
       if (this.recvBuf.length >= offset + 12 + msgSize) {
         await this.processMsg(msgId,
                                this.recvBuf.slice