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

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 <redacted>
---
 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],

+		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

@@ -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