The Mbed TLS server keeps the SNI from the ClientHello in a
thread-local until the handshake succeeds, and its SNI callback only
runs for a ClientHello that carries one. A handshake that failed left
its SNI behind, so the next connection served by the same thread
without SNI reported the earlier client's name in req.sni(). Start
each handshake with the thread-local cleared.
yhirose
7a9cee0e05
