(ITS#8360) apparent MDB corruption when hitting maxsize

[peter.van.dijk@powerdns.com]

Full_Name: Peter van Dijk
Version: 2.4.43
OS: Mac OS X 10.10.5
URL: ftp://ftp.openldap.org/incoming/
Submission from: (NULL) (2001:610:666:0:c92b:7aa7:bc73:c430)


The procedure follow is fully repeatable with consistent problematic results for
me.

(1) ftp://ftp.openldap.org/pub/OpenLDAP/openldap-release/openldap-2.4.43.tgz,
installed via osx homebrew with configure flags
--prefix=/usr/local/Cellar/openlp%p/2.4.43 --sysconfdir=/usr/local/etc
--localstatedir=/usr/local/var

(2) config and related files as uploaded on the given URL (cosine.schema is
unedited but included for completeness)

(3) /usr/local/var/openldap-data/ is empty

(4) sudo /usr/local/opt/openldap/libexec/slapd -d 255 -u peter 2> slapd.log

(5) ldapmodify -D 'uid=peter,o=habbie' -w secret -c < named.conf.ldif  2>
ldapmodify.log ; ldapdelete -D 'uid=peter,o=habbie' -w secret -r ou=dns,o=habbie
2> ldapdelete.log
modify is unhappy, initially because of some unknown attributes (thish is why I
used -c), then later because it is hitting the MDB maxsize of 10 megabytes.
ldapdelete then fails to delete the ou=dns tree due to MDB errors

(6) increasing maxsize after this 'corruption' has happened does NOT enable
ldapdelete to suddenly work

(7) (with slapd stopped, not sure it matters): $
/usr/local/opt/openldap/sbin/slapcat outputs 191771 lines to stdout before
aborting with:
56a63063 mdb_entry_decode: attribute index 24 not recognized
Segmentation fault: 11

(8) as requested by hyc on IRC, copying here for completeness 

$ mdb_dump -p -s ad2i /usr/local/var/openldap-data/
VERSION=3
format=print
database=ad2i
type=btree
mapsize=10485760
maxreaders=126
tetegerkey=1
db_pagesize=4096
HEADER=END
 \01\00\00\00
 objectClass
 \02\00\00\00
 o
 \03\00\00\00
 structuralObjectClass
 \04\00\00\00
 entryUUID
 \05\00\00\00
 creatorsName
 \06\00\00\00
 createTimestamp
 \07\00\00\00
 entryCSN
 \08\00\00\00
 modifiersName
 \09\00\00\00
 modifyTimestamp
 \0a\00\00\00
 ou
 \0b\00\00\00
 dc
 \0c\00\00\00
 associatedDomain
 \0d\00\00\00
 dNSTTL
 \0e\00\00\00
 sOARecord
 \0f\00\00\00
 nSRecord
 \10\00\00\00
 mXRecord
 \11\00\00\00
 aRecord
 \12\00\00\00
 cMEReRecord
 \13\00\00\00
 LocRecord
 \14\00\00\00
 hInfoRecord
 \15\00\00\00
 tXTRecord
 \16\00\00\00
 aAAARecord
DATA=END