(ITS#4112) component match indexing is broken

[hyc@OpenLDAP.org]

Full_Name: Howard Chu
Version: 2.3
OS: Linux
URL: ftp://ftp.openldap.org/incoming/
Submission from: (NULL) (24.126.120.178)
Submitted by: hyc


The back-bdb component match indexing code stores per-attribute state
information in the AttrInfo structures. These structures are supposed to be
read-only; they are shared by all threads running in the backend. If two entries
are being added at once and component indices are in use they will collide here.
This code cannot be used.