[PATCH 1/1] midx.c: fix an integer overflow

From: Damien Robert <damien.olivier.robert@gmail.com>
Date: Feb 28, 2020, 16:24 UTC
Message-ID: <20200228162450.1720795-1-damien.olivier.robert+git@gmail.com>

When verifying a midx index with 0 objects, the
    m->num_objects - 1
overflows to 4294967295.

Fix this.

Signed-off-by: Damien Robert <damien.olivier.robert+git@gmail.com>
---
 midx.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/midx.c b/midx.c
index 37ec28623a..6ffe013089 100644
--- a/midx.c
+++ b/midx.c
@@ -1127,7 +1127,7 @@ int verify_midx_file(struct repository *r, const char *object_dir, unsigned flag
 	if (flags & MIDX_PROGRESS)
 		progress = start_sparse_progress(_("Verifying OID order in multi-pack-index"),
 						 m->num_objects - 1);
-	for (i = 0; i < m->num_objects - 1; i++) {
+	for (i = 0; i + 1 < m->num_objects; i++) {
 		struct object_id oid1, oid2;
 
 		nth_midxed_object_oid(&oid1, m, i);

-- 
Patched on top of v2.25.1-379-gd22418c625 (git version 2.25.1)