Re: [PATCH] unpack-trees: do not set SKIP_WORKTREE on submodules

>
> On Wed, Jun 17, 2020 at 9:24 PM Elijah Newren <newren@gmail.com> wrote:
> >
> > If someone were
> > to try do change their sparsity patterns or even just run a "git
> > sparse-checkout reapply" when they had the above issues, they'd see
> > something like:
> >
> >     $ git sparse-checkout reapply
> >     warning: The following paths are unmerged and were left despite
> > sparse patterns:
> >             filename_with_conflicts
> >
> >     After fixing the above paths, you may want to run `git
> > sparse-checkout reapply`.
> >
> > This basically suggests that we consider uncommitted and unmerged
> > files to be "unclean" in some way (sparse-checkout wants to set the
> > SKIP_WORKTREE bit on all files that do not match the sparsity
> > specification, so "clean" means sparse-checkout is able to do so).  So
> > I could amend my earlier comparison and say that IF the user has a
> > clean directory, then "git grep --recurse-submodules $REVISION
> > $PATTERN" should be equivalent to "git checkout $REVISION && git grep
> > --recurse-submodules $PATTERN".  I could also say that given the big
> > warnings we give users when we can't set the SKIP_WORKTREE bit, that
> > we expect it to be a transient state and thus that we expect them to
> > more likely than not clear it out by the time they do switch branches.
> > That would lead us to the follow-up rule that if the user does not
> > have a clean directory then "git grep --recurse-submodules $REVISION
> > $PATTERN" should be equivalent to what you would get if the unclean
> > entries were ignored (expecting them to be cleaned before the any `git
> > checkout` could be run) and you then otherwise ran "git checkout
> > $REVISION && git grep --recurse-submodules $PATTERN".
>
> Makes sense, thanks! We haven't mentioned "git grep --cached" yet, but
> it would behave in the same way of the worktree grep, in this case.
> (I.e. searching the submodules, as their SKIP_WORTREE bit was not
> set.) So I guess it should be fine, as well.

> > That suggests that grep's implementation we agreed on earlier is still
> > correct (when given a $REVISION ignore submodulees that do not match
> > the sparsity patterns), but that unpack-trees/sparse-checkout still
> > need an update:
> >
> > When we notice an initialized submodule that does not match the
> > sparsity patterns, we should print a warning just like we do for
> > unmerged and dirty entries.
>
> Yeah, seems like a good approach. Thanks for the explanations. Some of
> the test cases in mt/grep-sparse-checkout will have to be adjusted
> with this change. Should I reroll the series based on the patch you
> will send or do you prefer to adjust them in your patch (and make it
> dependent on mt/grep-sparse-checkout)?