Thank you for taking the time to report this bug and helping to make Ubuntu better.
It is certainly confusing that PAM uses /etc/ldap.conf whereas openldap uses /etc/ldap/ldap.conf. But it isn't clear to me that these two files are actually of the same format, or that it is guaranteed that one is a superset of the other.
The pam_ldap(5) manpage says:
pam_ldap stores its configuration in the ldap.conf file. (It should
be noted that some LDAP client libraries, such as OpenLDAP, also
use a configuration file of the same name. pam_ldap supports many
of the same configuration file options as OpenLDAP, but it adds
several that are specific to the functionality it provides. It is
not guaranteed that pam_ldap will continue to match the configura‐
tion file semantics of OpenLDAP. You may wish to use different
files.)
I think that doing something such as your symlink would have unintended consequences, so I'm not sure that a fix for the general case is trivial. And any change would best be coordinated with Debian.
Thank you for taking the time to report this bug and helping to make Ubuntu better.
It is certainly confusing that PAM uses /etc/ldap.conf whereas openldap uses /etc/ldap/ ldap.conf. But it isn't clear to me that these two files are actually of the same format, or that it is guaranteed that one is a superset of the other.
The pam_ldap(5) manpage says:
pam_ldap stores its configuration in the ldap.conf file. (It should
be noted that some LDAP client libraries, such as OpenLDAP, also
use a configuration file of the same name. pam_ldap supports many
of the same configuration file options as OpenLDAP, but it adds
several that are specific to the functionality it provides. It is
not guaranteed that pam_ldap will continue to match the configura‐
tion file semantics of OpenLDAP. You may wish to use different
files.)
I think that doing something such as your symlink would have unintended consequences, so I'm not sure that a fix for the general case is trivial. And any change would best be coordinated with Debian.