When an SslTlsSupport pipeline stage needs to queue outgoing messages, for example during initial SSL negotiation, it breaks with an exception when the recursive processPendingSends is eventually called to process the queued messages.

The reason is that the recursive call inside processPendingSends does not reference the nextCmds value. It should call processPendingSends(tempBuf, nextCmds) instead of processPendingSends(tempBuf). The tempBuf parameter to processPendingSends could actually be dropped, it not used inside the function.

The problem is present in Akka 2.2.1 (and I think since the SslTlsSupport class was introduced).