Typecasting causing undefined behavior

[taubel]

In er-coap-13.c there is the following code:

    x = &option_delta;
    do
    {
      if (*x==13)
      {
        *x += current_option[0];
        ++current_option;
      }
      else if (*x==14)
      {
        *x += 255;
        *x += current_option[0]<<8;
        ++current_option;
        *x += current_option[0];
        ++current_option;
      }
    }
    while (x!=(unsigned int *)&option_length && (x=(unsigned int *)&option_length));

Both option_delta and x are of type unsigned int, while option_length is of type size_t. In some systems these types are of different sizes, thus such code causes undefined behavior. My suggestion would be to change the type of option_length to unsigned int.