Re: One question about git-format-patch

I’m a git user, and recently I’ve noticed there’re some differences between
“$ git format-patch –n” and “$ git format-patch HEAD~n”. According to the
documentation: “-<n> Prepare patches from the topmost <n> commits.”

Correct.  However, HEAD~n will prepare patches for commits that are
not ancestor of HEAD~n.

And there may well be a lot more than n such commits, unless you are
working on a strictly linear history.