[PATCH 02/20] write_reuse_object(): convert to new revindex API

From: Taylor Blau <me@ttaylorr.com>
To: git@vger.kernel.org
Cc: peff@peff.net, jrnieder@gmail.com
Subject: [PATCH 02/20] write_reuse_object(): convert to new revindex API
Date: Fri, 8 Jan 2021 13:16:48 -0500	[thread overview]
Message-ID: <00668523e1cd860f6de08dd7c5a2a54edc08b7b6.1610129796.git.me@ttaylorr.com> (raw)
In-Reply-To: <cover.1610129796.git.me@ttaylorr.com>

First replace 'find_pack_revindex()' with its replacement
'offset_to_pack_pos()'. This prevents any bogus OFS_DELTA that may make
its way through until 'write_reuse_object()' from causing a bad memory
read (if 'revidx' is 'NULL')

Next, replace a direct access of '->nr' with the wrapper function
'pack_pos_to_index()'.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
---
 builtin/pack-objects.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
index 2a00358f34..03d25db442 100644
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c
@@ -419,7 +419,7 @@ static off_t write_reuse_object(struct hashfile *f, struct object_entry *entry,
 {
 	struct packed_git *p = IN_PACK(entry);
 	struct pack_window *w_curs = NULL;
-	struct revindex_entry *revidx;
+	uint32_t pos;
 	off_t offset;
 	enum object_type type = oe_type(entry);
 	off_t datalen;
@@ -436,10 +436,13 @@ static off_t write_reuse_object(struct hashfile *f, struct object_entry *entry,
 					      type, entry_size);
 
 	offset = entry->in_pack_offset;
-	revidx = find_pack_revindex(p, offset);
-	datalen = revidx[1].offset - offset;
+	if (offset_to_pack_pos(p, offset, &pos) < 0)
+		die(_("write_reuse_object: could not locate %s"),
+		    oid_to_hex(&entry->idx.oid));
+	datalen = pack_pos_to_offset(p, pos + 1) - offset;
 	if (!pack_to_stdout && p->index_version > 1 &&
-	    check_pack_crc(p, &w_curs, offset, datalen, revidx->nr)) {
+	    check_pack_crc(p, &w_curs, offset, datalen,
+			   pack_pos_to_index(p, pos))) {
 		error(_("bad packed object CRC for %s"),
 		      oid_to_hex(&entry->idx.oid));
 		unuse_pack(&w_curs);
-- 
2.30.0.138.g6d7191ea01

