In a couple places we already check if the socket is connected,
however we can be connected _and_ have the socket be closed.
The logic behind that I don't really understand, but there are
similar checks for validity in the OpenSSL backend.
This happens when calling close() on a still-connecting
socket. The QIODevice is marked as closed, but the connection
cannot yet be aborted. And when it finishes connecting we
handle the signal, start encryption, and then disconnect.
Pick-to: 6.6 6.5
Fixes: QTBUG-116550
Change-Id: I06c0a2db32bea0b573a99a971b8fb0b66a7a73d5
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
3ea46fa978