Network connection goes deaf. about ethernetenc HOT 3 OPEN

the error I found 'hidden in plain sight' was not an error, but my confusion about if (*this) (which executes the bool operator). I replaced it with if (data) and after I realized my misunderstanding of if (*this) I changed it back.

UIPClient::operator bool()
{
  UIPEthernetClass::tick();
  return data && (!(data->state & UIP_CLIENT_REMOTECLOSED) || data->packets_in[0] != NOBLOCK);
}

data is not null if the client is initialized.
!(data->state & UIP_CLIENT_REMOTECLOSED) is that it is connected
data->packets_in[0] != NOBLOCK is that it has data.
so it is initialized and (connected or has_data)

if (*this) is used to skip available(), peek(), read() and discardReceived() (which is flush() n UIPEthernet).

from ethernetenc.

The "fix" really did solve the problem in my case. The idea that I had was that the fix prevented
dereferencing an invalid pointer, which generally results in difficult to understand bugs.

I am very fluent in C but not so much with C++. I tried to get GDB running on the ESP chip but
was not successful, so debugging required using printf. Can you suggest some debug test that
I can do to help find this problem.

from ethernetenc.

the difference is tick() and this part of the bool operator implementation:
(!(data->state & UIP_CLIENT_REMOTECLOSED) || data->packets_in[0] != NOBLOCK)
instead of *this in available(), peek(), read() try
data && (!(data->state & UIP_CLIENT_REMOTECLOSED) || data->packets_in[0] != NOBLOCK)
this will remove tick() from available(), peek(), read()

from ethernetenc.