(ITS#8307) startup failed with DDS enabled

[boesch@fhv.at]

Full_Name: Christian B.sch
Version: 2.4.42
OS: FreeBSD 10.2
URL: ftp://ftp.openldap.org/incoming/
Submission from: (NULL) (2001:628:2130:4458::93)


I installed OpenLDAP 2.4.42, enabled these overlays on the mdb database:
olcOverlay={0}syncprov.ldif
olcOverlay={1}dds.ldif
olcOverlay={2}accesslog.ldif
olcOverlay={3}unique.ldif
olcOverlay={4}ppolicy.ldif
olcOverlay={5}refint.ldif
olcOvery%y={6}memberof.ldif
olcOverlay={7}dynlist.ldif
started, everything is fine.

Then I added an empty base tree:
dn: dc=example,dc=net
objectClass: dcObject
objectClass: organization
o: ORG
dc: example

dn: cn=admin,dc=example,dc=net
objectClass: organizationalRole
cn: LDAP Admin
cn: admin

dn: o=org,dc=example,dc=net
o: ORG
objectClass: organization
objectClass: top

After that, if slapd is restarted:
/usr/local/etc/rc.d/slapd: WARNING: failed to start slapd

If the db files are removed again, the startup works again, and if the dds
overlay is removed
the startup is always working even if the database isn't empty.