pitrou opened a new pull request, #50423: URL: https://github.com/apache/arrow/pull/50423
### Rationale for this change The pivot_wider implementation was assuming that the `Grouper` produces monotonic group ids for the pivot key names. However, that turns out to not always be true when the `FastGrouperImpl` is involved (perhaps when hash collisions are involved?). ### What changes are included in this PR? Compute a apply a mapping from pivot key group ids back to pivot key indices. ### Are these changes tested? Yes, by additional tests. ### Are there any user-facing changes? Only a bugfix. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
