Re: (ITS#6157) unAbandonable operations aren't.

[h.b.furuseth@usit.uio.no]

Suggested partual fix - add this possible value for o_cancel:
    #define SLAP_CANCEL_INVALID 0x04 /* like 0 but prevents Cancel */

Something like this:
    http://folk.uio.no/hbf/OpenLDAP/cancel-cancel.txt

Does not reject abandon(Cancel/StartTLS), would need to extend o_cancel
with yet another value.  That's ugly enough already, so I let that wait.
connection_abandon() in particular isn't invalid client action, but it
shouldn't be worse than causing a surprising result code or not response
before closing the connection.

Does not address syncprov's Cancel handler.

I don't know if the bconfig.c pathces are correct, but need to reject
cancel before (reacting to) thread pool pauses there and maybe in
syncrepl/syncprov.

-- 
Hallvard