Select a server from ldap_init serverlist (ITS#861)

[pmasarati@bci.it]

Full_Name: Pierangelo Masarati
Version: 2.0.6/HEAD
OS: Linux
URL: ftp://ftp.openldap.org/incoming/
Submission from: (NULL) (151.99.223.33)


I felt the need to access the serverlist that is given ldap_init,
to abort a connection due to search timeout in order to try again with another 
server in the list (Mail to openldap-software entitled "reliability of LDAP 
lookups").

In my opinion this feature, thought to avoid sendmail rejection (now queueing as

of 8.11.x)) of mail in case the DS does not reply promptly for any reason
besides
server down, could be of interest to a number of applications.

I prepared a simple patch, which I uploaded by ftp to www.openldap.org as
incoming/pierangelo-masarati-001028.patch, that keeps track of the URL
descriptor
that is used to actually connect to the server in `ldap_new_connection'.
Then, I added a function (which could possibly be added to the API, if you find
it 
useful), called `ldap_open_next'. This function closes the current connection
and tries to open a new one starting from the next server in the server list.

I wrote the and tested the patch with OpenLDAP 2.0.6, and checked it also with
the 
current HEAD branch with positive results. Please consider the need and the 
opportunity to add this feature to the development branch.

If there is any other means to obtain the same result, discard everything and
let 
me know!

Pierangelo Masarati.