Merge branch 'ab/hooks-regression-fix' into maint

A follow-up fix to a fix for a regression in 2.36.
source: <patch-1.1-2450e3e65cf-20220805T141402Z-avarab@gmail.com>

* ab/hooks-regression-fix:
  hook API: don't segfault on strbuf_addf() to NULL "out"

hook.c

@@ -62,9 +62,6 @@ static int pick_next_hook(struct child_process *cp,
 	strvec_push(&cp->args, hook_path);
 	strvec_pushv(&cp->args, hook_cb->options->args.v);
 
-	/* Provide context for errors if necessary */
-	*pp_task_cb = (char *)hook_path;
-
 	/*
 	 * This pick_next_hook() will be called again, we're only
 	 * running one hook, so indicate that no more work will be
@@ -80,13 +77,9 @@ static int notify_start_failure(struct strbuf *out,
 				void *pp_task_cp)
 {
 	struct hook_cb_data *hook_cb = pp_cb;
-	const char *hook_path = pp_task_cp;
 
 	hook_cb->rc |= 1;
 
-	strbuf_addf(out, _("Couldn't start hook '%s'\n"),
-		    hook_path);
-
 	return 1;
 }
 

t/t1800-hook.sh

@@ -151,4 +151,30 @@ test_expect_success TTY 'git commit: stdout and stderr are connected to a TTY' '
 	test_hook_tty commit -m"B.new"
 '
 
+test_expect_success 'git hook run a hook with a bad shebang' '
+	test_when_finished "rm -rf bad-hooks" &&
+	mkdir bad-hooks &&
+	write_script bad-hooks/test-hook "/bad/path/no/spaces" </dev/null &&
+
+	# TODO: We should emit the same (or at least a more similar)
+	# error on Windows and !Windows. See the OS-specific code in
+	# start_command()
+	if test_have_prereq !WINDOWS
+	then
+		cat >expect <<-\EOF
+		fatal: cannot run bad-hooks/test-hook: ...
+		EOF
+	else
+		cat >expect <<-\EOF
+		error: cannot spawn bad-hooks/test-hook: ...
+		EOF
+	fi &&
+	test_expect_code 1 git \
+		-c core.hooksPath=bad-hooks \
+		hook run test-hook >out 2>err &&
+	test_must_be_empty out &&
+	sed -e "s/test-hook: .*/test-hook: .../" <err >actual &&
+	test_cmp expect actual
+'
+
 test_done