(ITS#5618) better error messages for syncrepl failure

[henson@acm.org]

Full_Name: Paul B. Henson
Version: 2.3.40
OS: Gentoo
URL: ftp://ftp.openldap.org/incoming/
Submission from: (NULL) (134.71.248.24)


I recently installed some updates and configuration changes on one of my
LDAP slaves. Replication broke mysteriously after that. The only thing logged
was "slapd[30723]: do_syncrepl: rid 001 retrying (9 retries left)"

I finally figured out that the search was failing with a protocol error because
derefAliases was set to always, a setting I had just added. It would be useful
if replication failure provided better error messages, something in the logs
indicating that a protocol error had occurred because of an invalid
dereferencing setting would have saved me a lot of time.

In addition, if it is a protocol error to dereference aliases in the context of
syncrepl, shouldn't the server just ignore that global configuration setting and
just do the right thing?