Re: [PATCH] filter-branch: resolve $commit^{tree} in no-index case

> Actually, I ended up not including the part about doing that comparison.
> So the commit message isn't _wrong_, but it is incomplete. This
> paragraph:
>
>   However, the value of $tree here is technically
>   user-visible. The user can provide arbitrary shell code at
>   this stage, which could itself have a similar assumption to
>   what is in git_commit_non_empty_tree. So the conservative
>   choice to fix this regression is to take the 20% hit and
>   give the pre-348d4f2 behavior.
>
> should start with something like:
>
>   We could try to make git_commit_non_empty_tree more clever.
>
> to make it clear why we care about the user-visibility of the variable
> in the first place.
>
> Here is a re-roll with that fixup.