Subject: Re: [PATCH v4 2/2] difftool -d: ensure that intent-to-add files are handled correctly

From: Junio C Hamano <[email-masked]>
Date: Thu, 25 Jun 2020 11:11:40 -0700

"Johannes Schindelin via GitGitGadget" <[email-masked]>
writes:

> From: Johannes Schindelin <[email-masked]>
>
> In https://github.com/git-for-windows/git/issues/2677, a `git difftool
> -d` problem was reported. The underlying cause was a bug in `git
> diff-files --raw` that we just fixed.

That leaves a gap between "there is some unspecified problem" and
"the problem was cased by such and such" that forces readers to
either know the problem at heart (may apply to you and me right now,
but I am not sure about me 3 months in the future) or go check the
external website.

Can we fill the gap by saying how seeing the object name of empty
blob (or worse, tree) instead of 0{40} made "difftool -d" upset?

Thanks.

> Signed-off-by: Johannes Schindelin <[email-masked]>
> ---
>  t/t7800-difftool.sh | 8 ++++++++
>  1 file changed, 8 insertions(+)
>
> diff --git a/t/t7800-difftool.sh b/t/t7800-difftool.sh
> index 29b92907e2..524f30f7dc 100755
> --- a/t/t7800-difftool.sh
> +++ b/t/t7800-difftool.sh
> @@ -720,6 +720,14 @@ test_expect_success SYMLINKS 'difftool --dir-diff handles modified symlinks' '
>  	test_cmp expect actual
>  '
>  
> +test_expect_success 'add -N and difftool -d' '
> +	test_when_finished git reset --hard &&
> +
> +	test_write_lines A B C >intent-to-add &&
> +	git add -N intent-to-add &&
> +	git difftool --dir-diff --extcmd ls
> +'
> +
>  test_expect_success 'outside worktree' '
>  	echo 1 >1 &&
>  	echo 2 >2 &&