Re: [PATCH 3/3] Mark new entries skip-worktree appropriately

> Nguyễn Thái Ngọc Duy wrote:
>
>> Sparse checkout updates worktree based on the old and new
>> skip-worktree status when $GIT_DIR/info/sparse-checkout changes:
>>
>> old = ce_skip_worktree(ce);           // current skip-worktree
>> new = will_have_skip_work_tree(ce);   // from $GIT..sparse-checkout
>> if (old && !new) add_file_back(ce);   // shrink checkout area
>> if (!old && new) remove_file_out(ce); [1] // enlarge checkout area
>>
>> New entries after merging will always have skip-worktree unset
>> (i.e. old = 0). If those files are filtered out by
>> $GIT_DIR/info/sparse-checkout (i.e. new != 0), then case [1] will
>> happen. But there is nothing to remove because they're new.
>
> When using unpack_trees to add a new file, there is no in-file
> index entry to grab the previous skip worktree bit from.  If it
> is outside the checkout area, we should pretend it was skipped before,
> too; otherwise a checkout can cause a file on disk whose name
> coincides with a newly added outside-worktree file to be deleted.
>
> Do I understand correctly?