[PATCH v2 1/4] setup: add an escape hatch for "no more default hash algorithm" change
- From
Junio C Hamano <gitster@pobox.com>
- Date
- May 13, 2024, 19:21 UTC
- Message-ID
- <20240513192112.866021-2-gitster@pobox.com>
- In-Reply-To
- <20240513192112.866021-1-gitster@pobox.com>
Partially revert c8aed5e8 (repository: stop setting SHA1 as the default object hash, 2024-05-07), to keep end-user systems still broken when we have gap in our test coverage but yet give them an escape hatch to set the GIT_TEST_DEFAULT_HASH_IS_SHA1=1 environment variable to revert to the previous behaviour.
Signed-off-by: Junio C Hamano <gitster@pobox.com> --- repository.c | 24 ++++++++++++++++++++++++ t/test-lib.sh | 4 ++++ 2 files changed, 28 insertions(+)
diff --git a/repository.c b/repository.c index 15c10015b0..6f67966e35 100644 --- a/repository.c +++ b/repository.c @@ -26,6 +26,30 @@ void initialize_repository(struct repository *repo) repo->parsed_objects = parsed_object_pool_new(); ALLOC_ARRAY(repo->index, 1); index_state_init(repo->index, repo); + + /* + * Unfortunately, we need to keep this hack around for the time being: + * + * - Not setting up the hash algorithm for `the_repository` leads to + * crashes because `the_hash_algo` is a macro that expands to + * `the_repository->hash_algo`. So if Git commands try to access + * `the_hash_algo` without a Git directory we crash. + * + * - Setting up the hash algorithm to be SHA1 by default breaks other + * commands when running with SHA256. + * + * This is another point in case why having global state is a bad idea. + * Eventually, we should remove this hack and stop setting the hash + * algorithm in this function altogether. Instead, it should only ever + * be set via our repository setup procedures. But that requires more + * work. + * + * As we discover the code paths that need fixing, we may remove this + * code completely, but we are not there yet. + */ + if (repo == the_repository && + git_env_bool("GIT_TEST_DEFAULT_HASH_IS_SHA1", 0)) + repo_set_hash_algo(repo, GIT_HASH_SHA1); } static void expand_base_dir(char **out, const char *in, diff --git a/t/test-lib.sh b/t/test-lib.sh index 79d3e0e7d9..36d311fb4a 100644 --- a/t/test-lib.sh +++ b/t/test-lib.sh @@ -542,6 +542,10 @@ export EDITOR GIT_DEFAULT_HASH="${GIT_TEST_DEFAULT_HASH:-sha1}" export GIT_DEFAULT_HASH + +GIT_TEST_DEFAULT_HASH_IS_SHA1=0 +export GIT_TEST_DEFAULT_HASH_IS_SHA1 + GIT_DEFAULT_REF_FORMAT="${GIT_TEST_DEFAULT_REF_FORMAT:-files}" export GIT_DEFAULT_REF_FORMAT GIT_TEST_MERGE_ALGORITHM="${GIT_TEST_MERGE_ALGORITHM:-ort}"
-- 2.45.0-145-g3e4a232f6e