Motivation:
To ensure that all bytes queued in OpenSSL/tcnative internal buffers we invoke SSL_shutdown again to stimulate OpenSSL to write any pending bytes. If this call fails we may call SSL_free and the associated shutdown method to free resources. At this time we may attempt to use the networkBIO which has already been freed and get a NPE.
Modifications:
- Don't call bioLengthByteBuffer(networkBIO) if we have called shutdown() in ReferenceCountedOpenSslEngine
Result:
Fixes https://github.com/netty/netty/issues/6466
70bcb40855