[ZODB-Dev] POSKeyError when transaction.commit after savepoint.rollback and connection.readCurrent

[Godefroid Chapelle]

Hi,

Plone 3 to 4 migration occasionally triggers a POSKeyError during 
transaction commit. See http://rpatterson.net/blog/poskeyerror-during-commit

I encountered the issue yesterday.

I committed a test and a fix in branch 3.10.

https://github.com/zopefoundation/ZODB/commit/6457bcfd07b3b77f240cbc6d60f222f0d40e8d5d

Before the fix, the test triggered a traceback very similar to the one 
seen when migrating Plone.

As I am not an expert of ZODB internals, I'd like someone to review my 
fix even if the test suite does not break.

Thanks
-- 
Godefroid Chapelle (aka __gotcha) http://bubblenet.be