(ITS#3602) potential SIGSEGV in bdb_referrals()

[ando@sys-net.it]

Full_Name: Pierangelo Masarati
Version: HEAD/2.3/2.2
OS: Linux (whitebox)
URL: ftp://ftp.openldap.org/incoming/
Submission from: (NULL) (81.72.89.40)


There's potential for a SIGSEGV (it ocurred on one of our machines) when
bdb_dn2entry() returns an error other than 0 or DB_NOTFOUND, thus not setting
"ei", because "ei" is later dereferenced __before__ checking the return code. 
I'm unable at the moment to reproduce the cause of the problem, which seems to
be very unlikely to occur except in very particular circumstances.  A fix is
being committed to HEAD.

p.