QSslKey: Algorithm is not set correctly to opaque when constructing from a handle

When building a QSslKey from a handle (the handle referring to an openssl EVP_PKEY) in Qt 5.9.*, the algorithm is not always set to QSsl::Opaque.

We have the case where we build a QSslKey from an EVP_PKEY which is a private key on a smartcard (accessed via p11) and with Qt 5.9.*, when we return that QSslKey from a method, the algorithm is set to QSsl::Rsa. This is an issue because when we call the handle() method on the QSslKey, we get a dummy RSA key that we can't use with the p11 interface anymore.

Please note that 5.7.0 and 5.7.1 didn't have this issue.

With the following code:

QSslKey loadKey()
{
    EVP_PKEY *k = NULL;
    QSslKey key;

    // Load k
    // k = ENGINE_load_private_key(...);

    key = QSslKey(Qt::HANDLE(k));

    return key;
}

void sign()
{
    QSslKey key;

    // ...

    key = loadKey();

    qDebug() << key;
}

We get the following output when building with Qt 5.9.2:

QSslKey(PrivateKey, RSA, 2048)

And the following output when building with Qt 5.7.1 (expected behavior):

QSslKey(PrivateKey, OPAQUE, -1)

 See comment below and attachments for a minimal, complete, and verifiable example.