@matheusbsbs / matheus-bagliano / commits / 796fda3f78

setup: fix reinit of repos with incompatible GIT_DEFAULT_REF_FORMAT

The GIT_DEFAULT_REF_FORMAT environment variable can be set to influence the default ref format that new repostiories shall be initialized with. While this is the expected behaviour when creating a new repository, it is not when reinitializing a repository: we should retain the ref format currently used by it in that case. This doesn't work correctly right now: $ git init --ref-format=files repo Initialized empty Git repository in /tmp/repo/.git/ $ GIT_DEFAULT_REF_FORMAT=reftable git init repo fatal: could not open '/tmp/repo/.git/refs/heads' for writing: Is a directory Instead of retaining the current ref format, the reinitialization tries to reinitialize the repository with the different format. This action fails when git-init(1) tries to write the ".git/refs/heads" stub, which in the context of the reftable backend is always written as a file so that we can detect clients which inadvertently try to access the repo with the wrong ref format. Seems like the protection mechanism works for this case, as well. Fix the issue by ignoring the environment variable in case the repo has already been initialized with a ref storage format. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Patrick Steinhardt committed Jan 30, 2025 at 17:24 UTC 796fda3f786b3cd5518462b46895244dfecad63c

2 files changed +12 -1

setup.c

+3 -1

@@ -2534,7 +2534,9 @@ static void repository_format_configure(struct repository_format *repo_fmt,

2534 ref_format = ref_storage_format_by_name(env);

2535 if (ref_format == REF_STORAGE_FORMAT_UNKNOWN)

2536 die(_("unknown ref storage format '%s'"), env);

2537 - repo_fmt->ref_storage_format = ref_format;

2537 + if (repo_fmt->version < 0 ||

2538 + repo_fmt->ref_storage_format == REF_STORAGE_FORMAT_UNKNOWN)

2539 + repo_fmt->ref_storage_format = ref_format;

2540 } else if (cfg.ref_format != REF_STORAGE_FORMAT_UNKNOWN) {

2541 repo_fmt->ref_storage_format = cfg.ref_format;

2542 }

t/t0001-init.sh

@@ -697,6 +697,15 @@ do

697 git -C refformat rev-parse --show-ref-format >actual &&

698 test_cmp expect actual

699 '

700 +

701 + test_expect_success "reinit repository with GIT_DEFAULT_REF_FORMAT=$format does not change format" '

702 + test_when_finished "rm -rf refformat" &&

703 + git init refformat &&

704 + git -C refformat rev-parse --show-ref-format >expect &&

705 + GIT_DEFAULT_REF_FORMAT=$format git init refformat &&

706 + git -C refformat rev-parse --show-ref-format >actual &&

707 + test_cmp expect actual

708 + '

709 done

710

711 test_expect_success "--ref-format= overrides GIT_DEFAULT_REF_FORMAT" '