From: "brian m. carlson" <sandals@crustytoothpaste•net>
To: <git@vger•kernel.org>
Cc: Junio C Hamano <gitster@pobox•com>,
Ezekiel Newren <ezekielnewren@gmail•com>,
Patrick Steinhardt <ps@pks•im>
Subject: [PATCH v3 16/16] object-file-convert: always make sure object ID algo is valid
Date: Sat, 7 Feb 2026 20:04:46 +0000 [thread overview]
Message-ID: <20260207200446.2837699-17-sandals@crustytoothpaste.net> (raw)
In-Reply-To: <20260207200446.2837699-1-sandals@crustytoothpaste.net>
In some cases, we zero-initialize our object IDs, which sets the algo
member to zero as well, which is not a valid algorithm number. This is
a bad practice, but we typically paper over it in many cases by simply
substituting the repository's hash algorithm.
However, our new Rust loose object map code doesn't handle this
gracefully and can't find object IDs when the algorithm is zero because
they don't compare equal to those with the correct algo field. In
addition, the comparison code doesn't have any knowledge of what the
main algorithm is because that's global state, so we can't adjust the
comparison.
To make our code function properly and to avoid propagating these bad
entries, if we get a source object ID with a zero algo, just make a copy
of it with the fixed algorithm. This has the benefit of also fixing the
object IDs if we're in a single algorithm mode as well.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste•net>
---
object-file-convert.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/object-file-convert.c b/object-file-convert.c
index e44c821084..f8dce94811 100644
--- a/object-file-convert.c
+++ b/object-file-convert.c
@@ -13,7 +13,7 @@
#include "gpg-interface.h"
#include "object-file-convert.h"
-int repo_oid_to_algop(struct repository *repo, const struct object_id *src,
+int repo_oid_to_algop(struct repository *repo, const struct object_id *srcoid,
const struct git_hash_algo *to, struct object_id *dest)
{
/*
@@ -21,7 +21,15 @@ int repo_oid_to_algop(struct repository *repo, const struct object_id *src,
* default hash algorithm for that object.
*/
const struct git_hash_algo *from =
- src->algo ? &hash_algos[src->algo] : repo->hash_algo;
+ srcoid->algo ? &hash_algos[srcoid->algo] : repo->hash_algo;
+ struct object_id temp;
+ const struct object_id *src = srcoid;
+
+ if (!srcoid->algo) {
+ oidcpy(&temp, srcoid);
+ temp.algo = hash_algo_by_ptr(repo->hash_algo);
+ src = &temp;
+ }
if (from == to || !to) {
if (src != dest)
prev parent reply other threads:[~2026-02-07 20:05 UTC|newest]
Thread overview: 118+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-10-27 0:43 [PATCH 00/14] SHA-1/SHA-256 interoperability, part 2 brian m. carlson
2025-10-27 0:43 ` [PATCH 01/14] repository: require Rust support for interoperability brian m. carlson
2025-10-28 9:16 ` Patrick Steinhardt
2025-10-27 0:43 ` [PATCH 02/14] conversion: don't crash when no destination algo brian m. carlson
2025-10-27 0:43 ` [PATCH 03/14] hash: use uint32_t for object_id algorithm brian m. carlson
2025-10-28 9:16 ` Patrick Steinhardt
2025-10-28 18:28 ` Ezekiel Newren
2025-10-28 19:33 ` Junio C Hamano
2025-10-28 19:58 ` Ezekiel Newren
2025-10-28 20:20 ` Junio C Hamano
2025-10-30 0:23 ` brian m. carlson
2025-10-30 1:58 ` Collin Funk
2025-11-03 1:30 ` brian m. carlson
2025-10-29 0:33 ` brian m. carlson
2025-10-29 9:07 ` Patrick Steinhardt
2025-10-27 0:43 ` [PATCH 04/14] rust: add a ObjectID struct brian m. carlson
2025-10-28 9:17 ` Patrick Steinhardt
2025-10-28 19:07 ` Ezekiel Newren
2025-10-29 0:42 ` brian m. carlson
2025-10-28 19:40 ` Junio C Hamano
2025-10-29 0:47 ` brian m. carlson
2025-10-29 0:36 ` brian m. carlson
2025-10-29 9:08 ` Patrick Steinhardt
2025-10-30 0:32 ` brian m. carlson
2025-10-27 0:43 ` [PATCH 05/14] rust: add a hash algorithm abstraction brian m. carlson
2025-10-28 9:18 ` Patrick Steinhardt
2025-10-28 17:09 ` Ezekiel Newren
2025-10-28 20:00 ` Junio C Hamano
2025-10-28 20:03 ` Ezekiel Newren
2025-10-29 13:27 ` Junio C Hamano
2025-10-29 14:32 ` Junio C Hamano
2025-10-27 0:43 ` [PATCH 06/14] hash: add a function to look up hash algo structs brian m. carlson
2025-10-28 9:18 ` Patrick Steinhardt
2025-10-28 20:12 ` Junio C Hamano
2025-11-04 1:48 ` brian m. carlson
2025-11-04 10:24 ` Junio C Hamano
2025-10-27 0:43 ` [PATCH 07/14] csum-file: define hashwrite's count as a uint32_t brian m. carlson
2025-10-28 17:22 ` Ezekiel Newren
2025-10-27 0:43 ` [PATCH 08/14] write-or-die: add an fsync component for the loose object map brian m. carlson
2025-10-27 0:43 ` [PATCH 09/14] hash: expose hash context functions to Rust brian m. carlson
2025-10-29 16:32 ` Junio C Hamano
2025-10-30 21:42 ` brian m. carlson
2025-10-30 21:52 ` Junio C Hamano
2025-10-27 0:44 ` [PATCH 10/14] rust: add a build.rs script for tests brian m. carlson
2025-10-28 9:18 ` Patrick Steinhardt
2025-10-28 17:42 ` Ezekiel Newren
2025-10-29 16:43 ` Junio C Hamano
2025-10-29 22:10 ` Ezekiel Newren
2025-10-29 23:12 ` Junio C Hamano
2025-10-30 6:26 ` Patrick Steinhardt
2025-10-30 13:54 ` Junio C Hamano
2025-10-31 22:43 ` Ezekiel Newren
2025-11-01 11:18 ` Junio C Hamano
2025-10-27 0:44 ` [PATCH 11/14] rust: add functionality to hash an object brian m. carlson
2025-10-28 9:18 ` Patrick Steinhardt
2025-10-29 0:53 ` brian m. carlson
2025-10-29 9:07 ` Patrick Steinhardt
2025-10-28 18:05 ` Ezekiel Newren
2025-10-29 1:05 ` brian m. carlson
2025-10-29 16:02 ` Ben Knoble
2025-10-27 0:44 ` [PATCH 12/14] rust: add a new binary loose object map format brian m. carlson
2025-10-28 9:18 ` Patrick Steinhardt
2025-10-29 1:37 ` brian m. carlson
2025-10-29 9:07 ` Patrick Steinhardt
2025-10-29 17:03 ` Junio C Hamano
2025-10-29 18:21 ` Junio C Hamano
2025-10-27 0:44 ` [PATCH 13/14] rust: add a small wrapper around the hashfile code brian m. carlson
2025-10-28 18:19 ` Ezekiel Newren
2025-10-29 1:39 ` brian m. carlson
2025-10-27 0:44 ` [PATCH 14/14] object-file-convert: always make sure object ID algo is valid brian m. carlson
2025-10-29 20:07 ` [PATCH 00/14] SHA-1/SHA-256 interoperability, part 2 Junio C Hamano
2025-10-29 20:15 ` Junio C Hamano
2025-11-11 0:12 ` Ezekiel Newren
2025-11-14 17:25 ` Junio C Hamano
2025-11-14 21:11 ` Junio C Hamano
2025-11-17 6:56 ` Junio C Hamano
2025-11-17 22:09 ` brian m. carlson
2025-11-18 0:13 ` Junio C Hamano
2025-11-19 23:04 ` brian m. carlson
2025-11-19 23:24 ` Junio C Hamano
2025-11-19 23:37 ` Ezekiel Newren
2025-11-20 19:52 ` Ezekiel Newren
2025-11-20 23:02 ` brian m. carlson
2025-11-20 23:11 ` Ezekiel Newren
2025-11-20 23:14 ` Junio C Hamano
2025-11-17 22:16 ` [PATCH v2 00/15] " brian m. carlson
2025-11-17 22:16 ` [PATCH v2 01/15] repository: require Rust support for interoperability brian m. carlson
2025-11-17 22:16 ` [PATCH v2 02/15] conversion: don't crash when no destination algo brian m. carlson
2025-11-17 22:16 ` [PATCH v2 03/15] hash: use uint32_t for object_id algorithm brian m. carlson
2025-11-17 22:16 ` [PATCH v2 04/15] rust: add a ObjectID struct brian m. carlson
2025-11-17 22:16 ` [PATCH v2 05/15] rust: add a hash algorithm abstraction brian m. carlson
2025-11-17 22:16 ` [PATCH v2 06/15] hash: add a function to look up hash algo structs brian m. carlson
2025-11-17 22:16 ` [PATCH v2 07/15] rust: add additional helpers for ObjectID brian m. carlson
2025-11-17 22:16 ` [PATCH v2 08/15] csum-file: define hashwrite's count as a uint32_t brian m. carlson
2025-11-17 22:16 ` [PATCH v2 09/15] write-or-die: add an fsync component for the object map brian m. carlson
2025-11-17 22:16 ` [PATCH v2 10/15] hash: expose hash context functions to Rust brian m. carlson
2025-11-17 22:16 ` [PATCH v2 11/15] rust: add a build.rs script for tests brian m. carlson
2025-11-17 22:16 ` [PATCH v2 12/15] rust: add functionality to hash an object brian m. carlson
2025-11-17 22:16 ` [PATCH v2 13/15] rust: add a new binary object map format brian m. carlson
2025-11-17 22:16 ` [PATCH v2 14/15] rust: add a small wrapper around the hashfile code brian m. carlson
2025-11-17 22:16 ` [PATCH v2 15/15] object-file-convert: always make sure object ID algo is valid brian m. carlson
2026-02-07 20:04 ` [PATCH v3 00/16] SHA-1/SHA-256 interoperability, part 2 brian m. carlson
2026-02-07 20:04 ` [PATCH v3 01/16] repository: require Rust support for interoperability brian m. carlson
2026-02-07 20:04 ` [PATCH v3 02/16] conversion: don't crash when no destination algo brian m. carlson
2026-02-07 20:04 ` [PATCH v3 03/16] hash: use uint32_t for object_id algorithm brian m. carlson
2026-02-07 20:04 ` [PATCH v3 04/16] rust: add a ObjectID struct brian m. carlson
2026-02-07 20:04 ` [PATCH v3 05/16] rust: add a hash algorithm abstraction brian m. carlson
2026-02-07 20:04 ` [PATCH v3 06/16] hash: add a function to look up hash algo structs brian m. carlson
2026-02-07 20:04 ` [PATCH v3 07/16] rust: add additional helpers for ObjectID brian m. carlson
2026-02-07 20:04 ` [PATCH v3 08/16] csum-file: define hashwrite's count as a uint32_t brian m. carlson
2026-02-07 20:04 ` [PATCH v3 09/16] write-or-die: add an fsync component for the object map brian m. carlson
2026-02-07 20:04 ` [PATCH v3 10/16] hash: expose hash context functions to Rust brian m. carlson
2026-02-07 20:04 ` [PATCH v3 11/16] rust: fix linking binaries with cargo brian m. carlson
2026-02-07 20:04 ` [PATCH v3 12/16] rust: add a build.rs script for tests brian m. carlson
2026-02-07 20:04 ` [PATCH v3 13/16] rust: add functionality to hash an object brian m. carlson
2026-02-07 20:04 ` [PATCH v3 14/16] rust: add a new binary object map format brian m. carlson
2026-02-07 20:04 ` [PATCH v3 15/16] rust: add a small wrapper around the hashfile code brian m. carlson
2026-02-07 20:04 ` brian m. carlson [this message]
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