Re: [PATCH 3/5] hook API: support passing stdin to hooks, convert am's 'post-rewrite'

diff --git a/hook.c b/hook.c
index a4fa1031f28..86c6dc1fe70 100644
--- a/hook.c
+++ b/hook.c

@@ -53,8 +53,14 @@ static int pick_next_hook(struct child_process *cp,
 	if (!hook_path)
 		return 0;
 
-	cp->no_stdin = 1;
 	strvec_pushv(&cp->env, hook_cb->options->env.v);
+	/* reopen the file for stdin; run_command closes it. */
+	if (hook_cb->options->path_to_stdin) {
+		cp->no_stdin = 0;
+		cp->in = xopen(hook_cb->options->path_to_stdin, O_RDONLY);
+	} else {
+		cp->no_stdin = 1;
+	}

diff --git a/hook.h b/hook.h
index 4258b13da0d..19ab9a5806e 100644
--- a/hook.h
+++ b/hook.h

@@ -30,6 +30,11 @@ struct run_hooks_opt
 	 * was invoked.
 	 */
 	int *invoked_hook;
+
+	/**
+	 * Path to file which should be piped to stdin for each hook.
+	 */
+	const char *path_to_stdin;
 };
 
 #define RUN_HOOKS_OPT_INIT { \