From 3324dd8f267cb59cdd42ac33727b6844921d5017 Mon Sep 17 00:00:00 2001
From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Wed, 29 Jun 2016 16:14:54 +0200
Subject: [PATCH] commit -S: avoid invalid pointer with empty message
While it is not recommended, fsck.c says:
Not having a body is not a crime [...]
... which means that we cannot assume that the commit buffer
contains an empty line to separate header from body. A commit
object with only a header without any body, not even without
a blank line after the header, is valid.
So let's tread carefully here. strstr("\n\n") may find nothing
and return NULL.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
commit.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/commit.c b/commit.c
index d1810c940b..ee7f0cb029 100644
--- a/commit.c
+++ b/commit.c
@@ -1092,9 +1092,14 @@ static int do_sign_commit(struct strbuf *buf, const char *keyid)
{
struct strbuf sig = STRBUF_INIT;
int inspos, copypos;
+ const char *eoh;
/* find the end of the header */
- inspos = strstr(buf->buf, "\n\n") - buf->buf + 1;
+ eoh = strstr(buf->buf, "\n\n");
+ if (!eoh)
+ inspos = buf->len;
+ else
+ inspos = eoh - buf->buf + 1;
if (!keyid || !*keyid)
keyid = get_signing_key();