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@xxxxxxxxx>
---
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
