https://bugs.openldap.org/show_bug.cgi?id=10229
--- Comment #2 from Nadezhda Ivanova nivanova@symas.com --- (In reply to Ondřej Kuzník from comment #1)
Does ITS#10060 (not in 2.6 though) relate to this in any way?
Doesn't seem so at the moment, it is in the same code, but this problem occurs when all=2 (MSG_RECEIVED) with a tv={0} (polling). Any other combination of these and things work as expected.