(ITS#3481) back-bdb fails to detect a deadlock in indexer

[hyc@OpenLDAP.org]

Full_Name: Howard Chu
Version: 2.1 - 2.3
OS: Linux
URL: 
Submission from: (NULL) (24.126.120.178)
Submitted by: hyc


The substring indexer calls bdb_key_change without checking its return code, so
if a deadlock occurs here it will not be detected and subsequent steps of the
parent operation will fail with EINVAL. For whatever reason, this error code
propagates all the way back to the client.