clone tips: partial, shallow, sparse

[Rudxain]

Note

disclaimer: I've only searched the codebase, I haven't actually used this software (yet)

I assume there's no feature for doing a partial or shallow clone, but if such feature were to be added, I have tips to share:

• If the user has a shallow clone, warn them before amending the grafted commit. Amending such commits will break the history
• If the user wants to do a shallow-clone, it's likely they also want to apply a --filter to it. Git allows clones to be shallow and partial at the same time. I have some experience with such repos, everything is fine so far!
• Before computing the blame of a file in a blobless-clone, use backfill to fetch faster (typically, this is not necessary for shallow+partial). I guess Git doesn't do this by default because backfill is experimental (according to the manpage)
• When rebasing 2 branches in a partial-clone, use --reapply-cherry-picks to avoid potential "infinite" loops when the branches differ too much
• If the user wants a --sparse checkout at clone-time, it's 99% likely they also want to apply a filter and run git config set merge.stat false. This ensures that git pull (which has --stat by default) doesn't fetch extra blobs to compute the summarized diff. Disabled stat is useless for non-sparse, because git will compute the diff anyways.

More info here