(ITS#8743) slaptest segfault with invalid back-meta configuration

[quanah@openldap.org]

Full_Name: Quanah Gibson-Mount
Version: 2.4.45
OS: N/A
URL: ftp://ftp.openldap.org/incoming/
Submission from: (NULL) (47.208.148.239)


When converting a slapd.conf file to cn=config, where the back-meta backend has
an invalid configuration for the "filter" directive, slaptest will segfault.  It
would be better to detect an error and exit accordingly.

This is trivial to reproduce by using the following directive:

filter "(objectClass=*)"

as per slapd-meta(5), the "filter" directive takes a regex(5) rather than an
LDAP filter.  Still, it should not cause a segfault. ;)