I have a question regarding libldap function ldap_install_tls().

If it fails, is it the right thing to call ldap_unbind_ext() after that?

If we call it, does it mean that ldap_install_tls() made a bind?
Or do we call ldap_install_tls() on the connection that is already bound? 

Sorry if the information is available somewhere, but I missed to find it.
The only thing I found is that OpenLDAP server calls ldap_unbind_ext() in case of failure but maybe I miss something...

Thank you,