Re: [PATCH 15/15] builtin/checkout: add --recurse-submodules switch

> Signed-off-by: Stefan Beller <sbeller@google.com>
> ---
>  Documentation/git-checkout.txt |  7 +++++++
>  builtin/checkout.c             | 28 ++++++++++++++++++++++++++++
>  t/lib-submodule-update.sh      | 33 ++++++++++++++++++++++++---------
>  t/t2013-checkout-submodule.sh  |  5 +++++
>  4 files changed, 64 insertions(+), 9 deletions(-)
> 
> diff --git a/Documentation/git-checkout.txt b/Documentation/git-checkout.txt
> index 8e2c0662dd..d6399c0af8 100644
> --- a/Documentation/git-checkout.txt
> +++ b/Documentation/git-checkout.txt
> @@ -256,6 +256,13 @@ section of linkgit:git-add[1] to learn how to operate the `--patch` mode.
>  	out anyway. In other words, the ref can be held by more than one
>  	worktree.
>  
> +--[no-]recurse-submodules::
> +	Using --recurse-submodules will update the content of all initialized
> +	submodules according to the commit recorded in the superproject. If
> +	local modifications in a submodule would be overwritten the checkout
> +	will fail unless `-f` is used. If nothing (or --no-recurse-submodules)
> +	is used, the work trees of submodules will not be updated.
> +
>  <branch>::
>  	Branch to checkout; if it refers to a branch (i.e., a name that,
>  	when prepended with "refs/heads/", is a valid ref), then that
> diff --git a/builtin/checkout.c b/builtin/checkout.c
> index f174f50303..207ce09771 100644
> --- a/builtin/checkout.c
> +++ b/builtin/checkout.c
> @@ -21,12 +21,31 @@
>  #include "submodule-config.h"
>  #include "submodule.h"
>  
> +static int recurse_submodules = RECURSE_SUBMODULES_DEFAULT;
> +
>  static const char * const checkout_usage[] = {
>  	N_("git checkout [<options>] <branch>"),
>  	N_("git checkout [<options>] [<branch>] -- <file>..."),
>  	NULL,
>  };
>  
> +int option_parse_recurse_submodules(const struct option *opt,
> +				    const char *arg, int unset)