When the server sends a line longer than _MAXLINE, nntplib reads only _MAXLINE + 1 bytes leaving the remaining bytes left to be processed by the next command that will interpret those bytes as a protocol error. Hence the failing tests that follow the first NNTPDataError exception in the failing test_nntplib.

The patch increases _MAXLINE from 2048 to 4096 and fixes the above problem. It also takes care to read up to (and including) the terminator so that the following lines or the terminator is not interpreted as a protocol error by the next nntp command.

The patch does not include a test case.