[PATCH v2 10/13] builtin/multi-pack-index: refuse unknown sources with "--object-dir="
- From
Patrick Steinhardt <ps@pks.im>
- Date
- Sep 2, 2026, 13:34 UTC
- Message-ID
- <20260902-pks-odb-registering-in-memory-sources-v2-10-c6ca12fdea4d@pks.im>
- In-Reply-To
- <20260902-pks-odb-registering-in-memory-sources-v2-0-c6ca12fdea4d@pks.im>
Users can tell git-multi-pack-index(1) to access multi-pack indices that are stored in a different object directory via the "--object-dir=" option. This allows them to for example write or verify a multi-pack index other than the one located in the main object directory in case a repository has alternates with multiple multi-pack indices.
But while the documentation explicitly points out that the specified object directory must be an alternate of the current repository, we never verify that property. Instead, starting with 017db7bb14 (midx: load multi-pack indices via their source, 2025-08-11), we now construct an ad-hoc source and link it to the main object directory.
Besides contradicting the documentation, it's dubious that this really ought to work in the first place: creating a multi-pack index (and potentially a bitmap) for a completely foreign object directory is of questionable value, as bitmap commit selection operates on the invoking repository's refs. Furthermore, this is the only remaining caller outside of our test helpers that constructs an ad-hoc source and links it to the database, and we want to get rid of this mechanism as part of this series.
Stop constructing the ad-hoc source and instead refuse the operation. While this results in a change in behaviour, this restriction has been documented as such ever since f57a739691 (midx: avoid opening multiple MIDXs when writing, 2021-09-01).
Note that this change requires us to adapt one test chain in t5319, as it creates an object directory that is not connected to any repository and then uses it via "--object-dir=". The setup itself already documents this and does the necessary gymnastics to link the object directory to a temporary repository, but subsequent tests don't. Adapt those tests to retain and reuse the temporary repository.
Signed-off-by: Patrick Steinhardt <ps@pks.im> --- builtin/multi-pack-index.c | 3 ++- t/t5319-multi-pack-index.sh | 9 ++++----- 2 files changed, 6 insertions(+), 6 deletions(-)
diff --git a/builtin/multi-pack-index.c b/builtin/multi-pack-index.c index 6e73c85cde..753bd53a70 100644 --- a/builtin/multi-pack-index.c +++ b/builtin/multi-pack-index.c @@ -90,7 +90,8 @@ static struct odb_source_files *handle_object_dir_option(struct repository *repo { struct odb_source *source = odb_find_source(repo->objects, opts.object_dir); if (!source) - source = odb_add_to_alternates_memory(repo->objects, opts.object_dir); + die(_("object directory is not an alternate of the current repository: '%s'"), + opts.object_dir); return odb_source_files_downcast(source); } diff --git a/t/t5319-multi-pack-index.sh b/t/t5319-multi-pack-index.sh index 68143cb5b7..00e90f163f 100755 --- a/t/t5319-multi-pack-index.sh +++ b/t/t5319-multi-pack-index.sh @@ -698,10 +698,9 @@ test_expect_success 'force some 64-bit offsets with pack-objects' ' corrupt_data $idx64 $(test_oid idxoff) "\02" && # objects64 is not a real repository, but can serve as an alternate # anyway so we can write a MIDX into it - git init repo && - test_when_finished "rm -fr repo" && + git init repo64 && ( - cd repo && + cd repo64 && ( cd ../objects64 && pwd ) >.git/objects/info/alternates && midx64=$(git multi-pack-index --object-dir=../objects64 write) ) && @@ -709,7 +708,7 @@ test_expect_success 'force some 64-bit offsets with pack-objects' ' ' test_expect_success 'verify multi-pack-index with 64-bit offsets' ' - git multi-pack-index verify --object-dir=objects64 + git -C repo64 multi-pack-index verify --object-dir=../objects64 ' NUM_OBJECTS=63 @@ -721,7 +720,7 @@ MIDX_BYTE_LARGE_OFFSET=$(($MIDX_OFFSET_LARGE_OFFSETS + 3)) test_expect_success 'verify incorrect 64-bit offset' ' corrupt_midx_and_verify $MIDX_BYTE_LARGE_OFFSET "\07" objects64 \ - "incorrect object offset" + "incorrect object offset" "git -C repo64 multi-pack-index verify --object-dir=../objects64" ' test_expect_success 'setup expire tests' '
-- 2.55.0.979.g7e5102b832.dirty