Segfaults in Psi+ and Psi when libqca2-plugin-ossl functions are required but this plugin is not installed

[tehnick]

Original bug report: http://bugs.debian.org/717350 But only one particular case is described there.

More abstract description of problem:

1. libqca2-plugin-ossl is optional dependency and it may be not installed in system.
2. Psi segfaults when libqca2-plugin-ossl functions are called but this plugin is not installed.
3. I asked QCA developer (taurus) and he replied that special check should be implemented in Psi to fix this problem. Something like this:

if(!QCA::isSupported("pkey") ||
        !QCA::PKey::supportedTypes().contains(QCA::PKey::RSA))
{
        // then there is no RSA key support
}
else
{
        // there is RSA key support
}

I am not sure what is better: modal dialog with error or something else.

[tehnick]

It is very strange: I can reproduce this segfault only on one from three of my accounts. On other accounts Psi works properly. See screenshots:

[Neustradamus]

@tehnick: What is the situation of this bug?