Support for old commit range like --ref HEAD~10..HEAD~5

[FirstLoveLife]

Hi,

Currently, git-filter-repo supports --ref HEAD~10..HEAD but not --refs HEAD~10..HEAD~5. May I know why, and if support for the latter is planned?

[newren]

The latter is not supported because it's impossible with Git's data model. Every commit has its parent ids embedded within it. If you rewrite older commits, you don't actually change the older commits but write new replacement ones with new commit IDs. Since the newer commits that you didn't rewrite are completely unaware of and don't use the older commits, the older commits that you "rewrote" aren't included anywhere and will just be garbage collected at some point. Once you rewrite a commit, you must rewrite every descendant of that commit down to all branches and tags and update the branches and tags to point to the new commit ids for a rewrite to be effective.

You can find more details about this over here: https://github.com/newren/git-filter-repo/blob/main/Documentation/FAQ.md#why-did-git-filter-repo-rewrite-more-commit-hashes-than-i-expected