When a user has no password and a polkit authentication is started,
instead of blindly initiating the admin session, show the regular
"Authentication Requested" dialog (but without the password entry). This
makes sure that the user's admin session is only effectively started
after the user chooses to proceed with the authentication, which
provides an extra confirmation step that can be vital for critical
tasks.
To do this, we show the dialog inside `_onUserChanged()` right after the
dialog was created instead of calling `performAuthentication()` from
`_onInitiate()`. The bug mentioned in `_onInitiate()` is no longer an
issue since we show the dialog in all cases now anyway.
Ideally we should use a different wording than "authentication" when the
user has no password set, and use "confirmation" instead. However polkit
already sends the requests with such messages (e.g. "Authentication is
required to configure software repositories"), and it's important to
show those to the user, so this patch keeps the regular wording.
https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/829
070c784412