From b0f6b6b523c58cb204292455ed7121896f0aa6ed Mon Sep 17 00:00:00 2001 From: Patrick Steinhardt Date: Tue, 27 Feb 2024 15:27:39 +0100 Subject: [PATCH] refs/reftable: don't fail empty transactions in repo without HEAD Under normal circumstances, it shouldn't ever happen that a repository has no HEAD reference. In fact, git-update-ref(1) would fail any request to delete the HEAD reference, and a newly initialized repository always pre-creates it, too. We have however changed git-clone(1) to partially initialize the refdb just up to the point where remote helpers can find the repository. With that change, we are going to run into a situation where repositories have no refs at all. Now there is a very particular edge case in this situation: when preparing an empty ref transacton, we end up returning whatever value `read_ref_without_reload()` returned to the caller. Under normal conditions this would be fine: "HEAD" should usually exist, and thus the function would return `0`. But if "HEAD" doesn't exist, the function returns a positive value which we end up returning to the caller. Fix this bug by resetting the return code to `0` and add a test. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano --- refs/reftable-backend.c | 1 + t/t0610-reftable-basics.sh | 13 +++++++++++++ 2 files changed, 14 insertions(+) diff --git a/refs/reftable-backend.c b/refs/reftable-backend.c index a14f2ad7f4..45568818f0 100644 --- a/refs/reftable-backend.c +++ b/refs/reftable-backend.c @@ -821,6 +821,7 @@ static int reftable_be_transaction_prepare(struct ref_store *ref_store, &head_referent, &head_type); if (ret < 0) goto done; + ret = 0; for (i = 0; i < transaction->nr; i++) { struct ref_update *u = transaction->updates[i]; diff --git a/t/t0610-reftable-basics.sh b/t/t0610-reftable-basics.sh index 6a131e40b8..c5f4d23433 100755 --- a/t/t0610-reftable-basics.sh +++ b/t/t0610-reftable-basics.sh @@ -328,6 +328,19 @@ test_expect_success 'ref transaction: writes are synced' ' EOF ' +test_expect_success 'ref transaction: empty transaction in empty repo' ' + test_when_finished "rm -rf repo" && + git init repo && + test_commit -C repo --no-tag A && + COMMIT=$(git -C repo rev-parse HEAD) && + git -C repo update-ref -d refs/heads/main && + test-tool -C repo ref-store main delete-refs REF_NO_DEREF msg HEAD && + git -C repo update-ref --stdin <<-EOF + prepare + commit + EOF +' + test_expect_success 'pack-refs: compacts tables' ' test_when_finished "rm -rf repo" && git init repo && -- 2.39.5