Warn other user is the data contains a zero

squinnondation/messages.py

@@ -301,6 +301,12 @@ class DataTLV(TLV):
                 "You are not my neighbour, I don't listen to your DataTLV. Please say me Hello before.")))
             return
 
+        if 0 in self.data:
+            user.send_packet(sender, Packet.construct(WarningTLV.construct(
+                f"The length of your DataTLV mismatches. You told me that the length is {len(self.data)} "
+                f"while a zero was found at index {self.data.index(0)}.")))
+            self.data = self.data[:self.data.index(0)]
+
         msg = self.data.decode('UTF-8')
 
         # Acknowledge the packet