On Fri, Jul 22, 2022 at 6:55 PM Junio C Hamano [off-list ref] wrote:

* en/merge-restore-to-pristine (2022-07-21) 7 commits
 - merge: do not exit restore_state() prematurely
 - merge: ensure we can actually restore pre-merge state
 - merge: make restore_state() restore staged state too
 - merge: fix save_state() to work when there are stat-dirty files
 - merge: do not abort early if one strategy fails to handle the merge
 - merge-resolve: abort if index does not match HEAD
 - merge-ort-wrappers: make printed message match the one from recursive

 When "git merge" finds that it cannot perform a merge, it should
 restore the working tree to the state before the command was
 initiated, but in some corner cases it didn't.

 Will merge to 'next'?
 source: [ref]

I just submitted a v5 based on some feedback from Ævar.

(Also, did you forget to update the source link by chance?  Your
referenced source link is v3, but the version in your tree is v4.)