Subject: Re: [PATCH v1 2/2] checkout: fix regression in checkout -b on intitial checkout

From: Junio C Hamano <[email-masked]>
Date: Fri, 18 Jan 2019 12:00:34 -0800

Ben Peart <[email-masked]> writes:

> From: Ben Peart <[email-masked]>
>
> When doing a 'checkout -b' do a full checkout including updating the working
> tree when doing the initial checkout.  This fixes the regression in behavior
> caused by fa655d8411 checkout: optimize "git checkout -b <new_branch>"
>
> Signed-off-by: Ben Peart <[email-masked]>
> ---
>  builtin/checkout.c         | 6 ++++++
>  t/t2018-checkout-branch.sh | 2 +-
>  2 files changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/builtin/checkout.c b/builtin/checkout.c
> index 6fadf412e8..af6b5c8336 100644
> --- a/builtin/checkout.c
> +++ b/builtin/checkout.c
> @@ -517,6 +517,12 @@ static int skip_merge_working_tree(const struct checkout_opts *opts,
>  	if (core_apply_sparse_checkout && !checkout_optimize_new_branch)
>  		return 0;
>  
> +	/*
> +	 * We must do the merge if this is the initial checkout
> +	 */
> +	if (is_cache_unborn())
> +		return 0;
> +

Yup, that's a trivial fix ;-)

>  	/*
>  	 * We must do the merge if we are actually moving to a new commit.
>  	 */
> diff --git a/t/t2018-checkout-branch.sh b/t/t2018-checkout-branch.sh
> index 35999b3adb..c438889b0c 100755
> --- a/t/t2018-checkout-branch.sh
> +++ b/t/t2018-checkout-branch.sh
> @@ -206,7 +206,7 @@ test_expect_success 'checkout -b after clone --no-checkout does a checkout of HE
>  	rev="$(git -C src rev-parse HEAD)" &&
>  	git clone --no-checkout src dest &&
>  	git -C dest checkout "$rev" -b branch &&
> -	test_must_fail test -f dest/a
> +	test -f dest/a
>  '

This is flipping the wrong thing.  Rather, introduce the whole test
as test_expect_failure that wants to make sure dest/a exists, and
with this 2/2 patch flip test_expect_failure into test_expect_success.

Thanks.