We've observed hanging threads in ServletOutputStreamImpl.writeBlocking() method.

After research it was discovered that issue was introduced by UNDERTOW-2425.

Those changes do not consider that SSLConduit.doWrap() method consumes buffer but bypass 'sent bytes' counter if a TLS re-handshake occurs.

So 'totalWritten' will never reach 'bytesToWrite' in ServletOutputStreamImpl.writeBlocking().