[PATCH 6/8] midx: read `OIDF` chunk with `pair_chunk_expect()`

From

Taylor Blau <me@ttaylorr.com>

Date

Oct 13, 2023, 19:25 UTC

Message-ID

<b39203b32c24772d5d8a257c4f647b7d9bd92d53.1697225110.git.me@ttaylorr.com>

In-Reply-To

<cover.1697225110.git.me@ttaylorr.com>

Signed-off-by: Taylor Blau <me@ttaylorr.com>
---
 midx.c | 21 ++++++---------------
 1 file changed, 6 insertions(+), 15 deletions(-)

diff --git a/midx.c b/midx.c
index 2f3863c936..38bf816cce 100644
--- a/midx.c
+++ b/midx.c
@@ -61,20 +61,6 @@ void get_midx_rev_filename(struct strbuf *out, struct multi_pack_index *m)
 	strbuf_addf(out, "-%s.rev", hash_to_hex(get_midx_checksum(m)));
 }
 
-static int midx_read_oid_fanout(const unsigned char *chunk_start,
-				size_t chunk_size, void *data)
-{
-	struct multi_pack_index *m = data;
-	m->chunk_oid_fanout = (uint32_t *)chunk_start;
-
-	if (chunk_size != 4 * 256) {
-		error(_("multi-pack-index OID fanout is of the wrong size"));
-		return 1;
-	}
-	m->num_objects = ntohl(m->chunk_oid_fanout[255]);
-	return 0;
-}
-
 static int midx_read_oid_lookup(const unsigned char *chunk_start,
 				size_t chunk_size, void *data)
 {
@@ -173,8 +159,13 @@ struct multi_pack_index *load_multi_pack_index(const char *object_dir, int local
 
 	if (pair_chunk(cf, MIDX_CHUNKID_PACKNAMES, &m->chunk_pack_names, &m->chunk_pack_names_len))
 		die(_("multi-pack-index required pack-name chunk missing or corrupted"));
-	if (read_chunk(cf, MIDX_CHUNKID_OIDFANOUT, midx_read_oid_fanout, m))
+	if (pair_chunk_expect(cf, MIDX_CHUNKID_OIDFANOUT,
+			      (const unsigned char **)&m->chunk_oid_fanout,
+			      256 * sizeof(uint32_t))) {
+		error(_("multi-pack-index OID fanout is of the wrong size"));
 		die(_("multi-pack-index required OID fanout chunk missing or corrupted"));
+	}
+	m->num_objects = ntohl(m->chunk_oid_fanout[255]);
 	if (read_chunk(cf, MIDX_CHUNKID_OIDLOOKUP, midx_read_oid_lookup, m))
 		die(_("multi-pack-index required OID lookup chunk missing or corrupted"));
 	if (read_chunk(cf, MIDX_CHUNKID_OBJECTOFFSETS, midx_read_object_offsets, m))

-- 
2.42.0.352.gd9c5062ff7.dirty