From f04c5b5522214cd48b39399d1d26b07848fd0e52 Mon Sep 17 00:00:00 2001
From: Michael Haggerty <mhagger@alum.mit.edu>
Date: Tue, 17 Feb 2015 18:00:19 +0100
Subject: [PATCH] ref_transaction_create(): check that new_sha1 is valid

Creating a reference requires a new_sha1 that is not NULL and not
null_sha1.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 refs.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/refs.c b/refs.c
index e3c4ab5fd5..b9cf284f31 100644
--- a/refs.c
+++ b/refs.c
@@ -3690,6 +3690,8 @@ int ref_transaction_create(struct ref_transaction *transaction,
 			   unsigned int flags, const char *msg,
 			   struct strbuf *err)
 {
+	if (!new_sha1 || is_null_sha1(new_sha1))
+		die("BUG: create called without valid new_sha1");
 	return ref_transaction_update(transaction, refname, new_sha1,
 				      null_sha1, flags, msg, err);
 }