don't do Buffer.write('', offset) as this might cause OOB error if offset is at the end of buffer (even if the string is empty)

Author: Andrey Sidorov

lib/packets/packet.js

@@ -731,6 +731,10 @@ Packet.prototype.writeString = function (s) {
     return;
   }
 
+  if (s.length === 0) {
+    return;
+  }
+
   var bytes = Buffer.byteLength(s, 'utf8');
   this.buffer.write(s, this.offset, bytes, 'utf8');
   this.offset += bytes;