slapd fails to perform search when there's unknown attribute in request (ITS#1204)

[deo@logos-m.ru]

Full_Name: egor duda
Version: 2.X CVS (Mon Jun 11 19:25:43 MSD 2001)
OS: Redhat Linux 6.2
URL: 
Submission from: (NULL) (195.7.187.66)


when client sends a search request that contains an attribute not listed in
schema, 
slapd skips this attribute and prints several "unknown filter type" messages
to the log. when it encounter unknown tag, however, filter parser skips the
tag itself, but not assosiated contents. as a result it comes to actual textual

data in filter contents but treats it as tag. proposed patch changes filter
parser
so that it skips entire element when it encounters unknown tag.
log of 'slapd -d 15' is available at 
http://ns.logos-m.ru/~deo/data/openldap/unknown-tag/slapd.log
patch is available at
http://ns.logos-m.ru/~deo/data/openldap/unknown-tag/egor-duda-010615.diff

probably my patch is a wrong way to solve this particular problem, i have 
very limited experience with ldap.