(ITS#5916) Allow alias dereferencing in search C API

[ando@sys-net.it]

Full_Name: Pierangelo Masarati
Version: HEAD
OS: irrelevant
URL: ftp://ftp.openldap.org/incoming/
Submission from: (NULL) (82.63.140.131)
Submitted by: ando


Proxy backends use ldap_set_option(3) to set alias dereferencing when requested
by a search operation (and do not clean it up afterwards, as far as I can tell).
 Since LDAP handlers are pooled and reused, this behavior is inherently broken.

The only reason for doing this is that the C API does not allow to explicitly
define alias dereferencing when sending a search request.

This is a feature request for an internal API extension (ldap_int_search*) that
allows alias dereferencing.  The current C API (essentially, ldap_search_ext*)
should wrap the new one, until promoted to public.

A patch is coming.

p.