Need someone to review pull request 13738

Could someone review this pull request (not mine) and see if it can be merged? It has been awaiting a merge for 4.8 years.

Done. If gh says there is a merge conflict, the patch cannot be merged. Otherwise, it can be, but if old enough (maybe a month or two), the patch should be updated from main and tests rerun. Anyway, I did some updates and summarized the current state, which is that someone familiar enough with tarfile decide if the tarfile change is actually correct. (This should better have been determined soon after the PR, and best before the patch was submitted.)