Re: [PATCH v2 3/8] merge-recursive: -Xindex-only to leave worktree unchanged

> Using the new no_worktree flag from the previous commit, we can teach
> merge-recursive to leave the worktree untouched.  Expose this with a
> new strategy option so that scripts can use it.
>
> Signed-off-by: Junio C Hamano <gitster@pobox.com>
> ---
> diff --git a/Documentation/merge-strategies.txt b/Documentation/merge-strategies.txt
> index fb6e593..2934e99 100644
> --- a/Documentation/merge-strategies.txt
> +++ b/Documentation/merge-strategies.txt
> @@ -92,6 +92,10 @@ subtree[=<path>];;
>         is prefixed (or stripped from the beginning) to make the shape of
>         two trees to match.
>
> +index-only;;

> +       Write the merge result only to the index; do not touch the
> +       worktree.
> +
>  octopus::
>         This resolves cases with more than two heads, but refuses to do
>         a complex merge that needs manual resolution.  It is