Subject: Re: [PATCH v9 34/37] git-send-email: use 'git hook run' for 'sendemail-validate'

From: Ævar Arnfjörð Bjarmason <[email-masked]>
Date: Thu, 27 May 2021 13:56:24 +0200

On Wed, May 26 2021, Emily Shaffer wrote:

> By using the new 'git hook run' subcommand to run 'sendemail-validate',
> we can reduce the boilerplate needed to run this hook in perl. Using
> config-based hooks also allows us to run 'sendemail-validate' hooks that
> were configured globally when running 'git send-email' from outside of a
> Git directory, alongside other benefits like multihooks and
> parallelization.
>
> Signed-off-by: Emily Shaffer <[email-masked]>
> ---
>  git-send-email.perl   | 26 ++++++--------------------
>  t/t9001-send-email.sh | 13 +------------
>  2 files changed, 7 insertions(+), 32 deletions(-)
>
> diff --git a/git-send-email.perl b/git-send-email.perl
> index 170f42fe21..b55687453e 100755
> --- a/git-send-email.perl
> +++ b/git-send-email.perl
> @@ -1958,26 +1958,12 @@ sub unique_email_list {
>  sub validate_patch {
>  	my ($fn, $xfer_encoding) = @_;
>  
> -	if ($repo) {
> -		my $validate_hook = catfile($repo->hooks_path(),
> -					    'sendemail-validate');
> -		my $hook_error;
> -		if (-x $validate_hook) {
> -			my $target = abs_path($fn);
> -			# The hook needs a correct cwd and GIT_DIR.
> -			my $cwd_save = cwd();
> -			chdir($repo->wc_path() or $repo->repo_path())
> -				or die("chdir: $!");
> -			local $ENV{"GIT_DIR"} = $repo->repo_path();
> -			$hook_error = system_or_msg([$validate_hook, $target]);
> -			chdir($cwd_save) or die("chdir: $!");
> -		}
> -		if ($hook_error) {
> -			die sprintf(__("fatal: %s: rejected by sendemail-validate hook\n" .
> -				       "%s\n" .
> -				       "warning: no patches were sent\n"), $fn, $hook_error);
> -		}
> -	}
> +	my $target = abs_path($fn);
> +
> +	system_or_die(["git", "hook", "run", "sendemail-validate", "-j1", "-a", $target],

How do we get the "benefit[ ... of ...] parallelization" here if -j1 is
hardcoded as parameter. Shouldn't that be removed so it'll use the
hook.jobs config like everything else?

> +		sprintf(__("fatal: %s: rejected by sendemail-validate hook\n" .
> +			   "warning: no patches were sent\n"),
> +		        $fn));
>  
>  	# Any long lines will be automatically fixed if we use a suitable transfer
>  	# encoding.
> diff --git a/t/t9001-send-email.sh b/t/t9001-send-email.sh
> index aa603cf4d0..bdf6472871 100755
> --- a/t/t9001-send-email.sh
> +++ b/t/t9001-send-email.sh
> @@ -539,7 +539,6 @@ test_expect_success $PREREQ "--validate respects relative core.hooksPath path" '
>  	test_path_is_file my-hooks.ran &&
>  	cat >expect <<-EOF &&
>  	fatal: longline.patch: rejected by sendemail-validate hook
> -	fatal: command '"'"'$PWD/my-hooks/sendemail-validate'"'"' died with exit code 1
>  	warning: no patches were sent
>  	EOF
>  	test_cmp expect actual
> @@ -557,7 +556,6 @@ test_expect_success $PREREQ "--validate respects absolute core.hooksPath path" '
>  	test_path_is_file my-hooks.ran &&
>  	cat >expect <<-EOF &&
>  	fatal: longline.patch: rejected by sendemail-validate hook
> -	fatal: command '"'"'$PWD/my-hooks/sendemail-validate'"'"' died with exit code 1
>  	warning: no patches were sent
>  	EOF
>  	test_cmp expect actual

Wouldn't it be better to keep the "died with exit code N" here. I.e. something like:

	fatal: longline.patch: rejected by sendemail-validate hook, 'git hook run' died with exit code %d

I.e. isn't that exit code carried forward by "git hook run"?

> @@ -2170,16 +2168,7 @@ test_expect_success $PREREQ 'invoke hook' '
>  	mkdir -p .git/hooks &&
>  
>  	write_script .git/hooks/sendemail-validate <<-\EOF &&
> -	# test that we have the correct environment variable, pwd, and
> -	# argument
> -	case "$GIT_DIR" in
> -	*.git)
> -		true
> -		;;
> -	*)
> -		false
> -		;;
> -	esac &&
> +	# test that we have the correct argument
>  	test -f 0001-add-main.patch &&
>  	grep "add main" "$1"
>  	EOF

We don't want to or need to check $GIT_DIR at all? Maybe not, but the
commit message doesn't say anything about it...