[ZODB-Dev] BTree corrupted after conflict resolution

[John Belmonte]

Dieter Maurer wrote:
> John Belmonte wrote at 2004-3-3 08:55 -0500:
> 
>>... "__cmp__" not called during conflict resolution ...
> 
> Maybe, I understand the problem:
> 
>   During conflict resolution the state does not contain
>   the persistent subobjects themselves but only references.
> 
>   Therefore, your "__cmp__" cannot be used to compare
>   the persistent subobjects. Almost surely, the default
>   "__cmp__" is used which is, of course, wrong and
>   can lead to corruption.

It seems you are right.  If I change the key class to a second-class 
object, the problem goes away.

> Almost surely, we must add a further restriction for BTrees:
> the keys must not be persistent objects.

I think that would be an unreasonable restriction.  If the server 
context can access the _p_conflictResolution method of a class, why not 
__cmp__, etc.?

-John


-- 
http:// if  ile.org/