Github user aarondav commented on the pull request:
https://github.com/apache/spark/pull/1461#issuecomment-49405145
This PR also changed the behavior with respect to mutating CoGroups -- now
we mutate combiner1 in place rather than returning a new ArrayBuffer. This is
_probably_ not an issue given our current usage of these combiners, but we
should be careful when making such seemingly innocuous changes, as they are
certainly not worth introducing a bug.
---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at [email protected] or file a JIRA ticket
with INFRA.
---
