(ITS#7339) back-mdb aborts with online index additions

[hyc@OpenLDAP.org]

Full_Name: Howard Chu
Version: HEAD/RE24
OS: 
URL: ftp://ftp.openldap.org/incoming/
Submission from: (NULL) (37.19.97.21)
Submitted by: hyc


Already fixed in d1a7fa267bdb9e27777ba87db44034ce83a75084

If new databases are added (such as when adding a new index via cn=config) they
may cause additional pages to be dirtied during txn_commit. The pages would be
pulled from the freelist. But the updates occurred after the freelist had
already been written out, so the new state of the freelist wasn't being saved.
Subsequent transactions would abort due to internal corruption.