Re: [PATCH] fiter-branch: fix commit map init from state branch

Hi Grant,

thanks for this patch: I hit the same bug, and I was about to report it.

Cc'ing Patrick and Junio, since the problem was introduced by f6d855091e (filter-branch: stop depending on Perl, 2025-04-16), released in 2.50.0.

I tested your fix with git 2.56.0, running filter-branch incrementally with --state-branch, --prune-empty and --subdirectory-filter:

- without the fix, the new commits are attached to the original
  parents instead of the rewritten ones, and swapped entries are saved
  back to the state branch;
- with the fix, the parents are the rewritten commits and the state
  is saved correctly.

Tested-by: Michele Locati <michele@locati.it>

We know that the use of filter-branch is not recommended, but we rely on --state-branch to split a repository incrementally, that is, processing only the new commits instead of the whole history at every run.

It would be great to have this fix merged.

A minor note: there's a typo in the subject ("fiter-branch").

Thanks, Michele