(ITS#5100) libldap allows controls to have NULL oid

[ando@sys-net.it]

Full_Name: Pierangelo Masarati
Version: HEAD/re23
OS: irrelevant
URL: ftp://ftp.openldap.org/incoming/
Submission from: (NULL) (81.72.89.40)
Submitted by: ando


In fact, ldap_control_dup() is willing to duplicate a control with NULL oid;
this is used by ldap_controls_dup(), which is the means used to set/get controls
using the ldap_set_option()/ldap_get_option() interface.

Since the LDAPOID field in controls is mandatory (RFC 4511), I think those
functions should actually error out if they find a missing oid.

p.