We have HTTP client code that calls HTTPSClientSession::sendRequest (with large requests, 60Kb or more).
In the situation of the server crashing/restarting (and the client catching an exception that says I/O Error, Broken Pipe), the client does a reset and then retries the same sendRequest.
In poco-1.4.3p1, the 'retry' works fine.
In poco-1.4.6p4, the 'retry' fails until we restart the client, or delete and re-create the client SSL context.
If we use HTTP instead of HTTPS, the 'retry' works fine in poco-1.4.6p4.
I would assert this is a bug in 1.4.6p4 .
From using tcpdump and wireshark to analyze the TCP stream from the client to the server, it looks like only a portion from the middle of the original large message is sent once the SSL negotiation completes.
Update - the problem was definitely introduced between 1.4.6p2 and 1.4.6p3 .