[PATCH v2 4/9] refs: do not run transaction hook for git-pack-refs

[Jiang Xin <worldhello.net@gmail.com>]

From: Jiang Xin <zhiyou.jx@alibaba-inc.com>

The git-pack-refs command will call "files_pack_refs()" to pack loose
references into the "packed-refs" file, and there are no real changes
to the repository. Therefore, by initializing a transaction with an
empty "hook_flags" field, the "reference-transaction" hook will not run.

The "prune_refs()" and "prune_ref()" functions are called from
"file_pack_refs()", and they are used to prune loose refereces which
have already been packed into "packed-refs". The transaction instance
in "prune_ref()" should also be initialized with an empty "hook_flags"
field.

The behavior of the following git commands and three testcases have been
fixed in t1416:

 * git gc
 * git pack-refs

Signed-off-by: Jiang Xin <zhiyou.jx@alibaba-inc.com>
---
 refs/files-backend.c             | 10 ++++++++--
 t/t1416-ref-transaction-hooks.sh | 12 +++---------
 2 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/refs/files-backend.c b/refs/files-backend.c
index 7c1c25a25c..f0947c9dca 100644
--- a/refs/files-backend.c
+++ b/refs/files-backend.c
@@ -1136,7 +1136,8 @@ static void prune_ref(struct files_ref_store *refs, struct ref_to_prune *r)
 	if (check_refname_format(r->name, 0))
 		return;
 
-	transaction = ref_store_transaction_begin(&refs->base, &err);
+	/* Called by "files_pack_refs()" and should not run any hooks. */
+	transaction = ref_store_transaction_begin_extended(&refs->base, 0, &err);
 	if (!transaction)
 		goto cleanup;
 	ref_transaction_add_update(
@@ -1207,7 +1208,12 @@ static int files_pack_refs(struct ref_store *ref_store, unsigned int flags)
 	struct strbuf err = STRBUF_INIT;
 	struct ref_transaction *transaction;
 
-	transaction = ref_store_transaction_begin(refs->packed_ref_store, &err);
+	/*
+	 * No real changes have occurred to the repository and no hooks
+	 * should be run for this transaction.
+	 */
+	transaction = ref_store_transaction_begin_extended(refs->packed_ref_store,
+							   0, &err);
 	if (!transaction)
 		return -1;
 
diff --git a/t/t1416-ref-transaction-hooks.sh b/t/t1416-ref-transaction-hooks.sh
index 1ae601a73d..b7ffc9415b 100755
--- a/t/t1416-ref-transaction-hooks.sh
+++ b/t/t1416-ref-transaction-hooks.sh
@@ -392,9 +392,7 @@ test_expect_success "update-ref: update HEAD" '
 	test_cmp_heads_and_tags -C workdir expect
 '
 
-# Failed because the reference-transaction hook was executed even
-# though no refs were changed by running git-pack-refs.
-test_expect_failure "update-ref: prepare packed_ref_store using pack-refs" '
+test_expect_success "update-ref: prepare packed_ref_store using pack-refs" '
 	test_when_finished "rm -f $HOOK_OUTPUT" &&
 	git -C workdir pack-refs --all &&
 	test_path_is_file workdir/.git/packed-refs &&
@@ -737,9 +735,7 @@ test_expect_success "branch: create new branches" '
 	test_cmp_heads_and_tags -C workdir expect
 '
 
-# Failed because the reference-transaction hook was executed even
-# though no refs were changed by running git-gc.
-test_expect_failure "branch: prepare packed_ref_store using gc" '
+test_expect_success "branch: prepare packed_ref_store using gc" '
 	test_when_finished "rm -f $HOOK_OUTPUT" &&
 	git -C workdir gc &&
 	test_path_is_file workdir/.git/packed-refs &&
@@ -1014,9 +1010,7 @@ test_expect_success "tag: create new tags" '
 	test_cmp_heads_and_tags -C workdir expect
 '
 
-# Failed because the reference-transaction hook was executed even
-# though no refs were changed by running git-pack-refs.
-test_expect_failure "tag: prepare packed_ref_store using pack-refs" '
+test_expect_success "tag: prepare packed_ref_store using pack-refs" '
 	test_when_finished "rm -f $HOOK_OUTPUT" &&
 	git -C workdir pack-refs --all &&
 	test_path_is_file workdir/.git/packed-refs &&
-- 
2.36.1.25.gc87d5ad63a.dirty