refs: accept symref values in `ref_transaction_update()`

The function `ref_transaction_update()` obtains ref information and
flags to create a `ref_update` and add them to the transaction at hand.

To extend symref support in transactions, we need to also accept the
old and new ref targets and process it. This commit adds the required
parameters to the function and modifies all call sites.

The two parameters added are `new_target` and `old_target`. The
`new_target` is used to denote what the reference should point to when
the transaction is applied. Some functions allow this parameter to be
NULL, meaning that the reference is not changed.

The `old_target` denotes the value the reference must have before the
update. Some functions allow this parameter to be NULL, meaning that the
old value of the reference is not checked.

We also update the internal function `ref_transaction_add_update()`
similarly to take the two new parameters.

Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

6 files changed, 8 insertions, 4 deletions

diff --git a/builtin/fast-import.c b/builtin/fast-import.c
index 782bda007c..6a0b39de32 100644
--- a/builtin/fast-import.c
+++ b/builtin/fast-import.c
@@ -1634,7 +1634,7 @@ static int update_branch(struct branch *b)
 	transaction = ref_transaction_begin(&err);
 	if (!transaction ||
 	    ref_transaction_update(transaction, b->name, &b->oid, &old_oid,
-				   0, msg, &err) ||
+				   NULL, NULL, 0, msg, &err) ||
 	    ref_transaction_commit(transaction, &err)) {
 		ref_transaction_free(transaction);
 		error("%s", err.buf);
@@ -1675,7 +1675,8 @@ static void dump_tags(void)
 		strbuf_addf(&ref_name, "refs/tags/%s", t->name);
 
 		if (ref_transaction_update(transaction, ref_name.buf,
-					   &t->oid, NULL, 0, msg, &err)) {
+					   &t->oid, NULL, NULL, NULL,
+					   0, msg, &err)) {
 			failure |= error("%s", err.buf);
 			goto cleanup;
 		}
diff --git a/builtin/fetch.c b/builtin/fetch.c
index 46a793411a..2b45778ab8 100644
--- a/builtin/fetch.c
+++ b/builtin/fetch.c
@@ -667,7 +667,7 @@ static int s_update_ref(const char *action,
 
 	ret = ref_transaction_update(transaction, ref->name, &ref->new_oid,
 				     check_old ? &ref->old_oid : NULL,
-				     0, msg, &err);
+				     NULL, NULL, 0, msg, &err);
 	if (ret) {
 		ret = STORE_REF_ERROR_OTHER;
 		goto out;
diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c
index 56d8a77ed7..ebea1747cb 100644
--- a/builtin/receive-pack.c
+++ b/builtin/receive-pack.c
@@ -1595,6 +1595,7 @@ static const char *update(struct command *cmd, struct shallow_info *si)
 		if (ref_transaction_update(transaction,
 					   namespaced_name,
 					   new_oid, old_oid,
+					   NULL, NULL,
 					   0, "push",
 					   &err)) {
 			rp_error("%s", err.buf);
diff --git a/builtin/replace.c b/builtin/replace.c
index da59600ad2..7690687b0e 100644
--- a/builtin/replace.c
+++ b/builtin/replace.c
@@ -201,7 +201,7 @@ static int replace_object_oid(const char *object_ref,
 	transaction = ref_transaction_begin(&err);
 	if (!transaction ||
 	    ref_transaction_update(transaction, ref.buf, repl, &prev,
-				   0, NULL, &err) ||
+				   NULL, NULL, 0, NULL, &err) ||
 	    ref_transaction_commit(transaction, &err))
 		res = error("%s", err.buf);
 
diff --git a/builtin/tag.c b/builtin/tag.c
index 9a33cb50b4..40a65fdebc 100644
--- a/builtin/tag.c
+++ b/builtin/tag.c
@@ -660,6 +660,7 @@ int cmd_tag(int argc, const char **argv, const char *prefix)
 	transaction = ref_transaction_begin(&err);
 	if (!transaction ||
 	    ref_transaction_update(transaction, ref.buf, &object, &prev,
+				   NULL, NULL,
 				   create_reflog ? REF_FORCE_CREATE_REFLOG : 0,
 				   reflog_msg.buf, &err) ||
 	    ref_transaction_commit(transaction, &err)) {
diff --git a/builtin/update-ref.c b/builtin/update-ref.c
index e46afbc46d..21fdbf6ac8 100644
--- a/builtin/update-ref.c
+++ b/builtin/update-ref.c
@@ -204,6 +204,7 @@ static void parse_cmd_update(struct ref_transaction *transaction,
 
 	if (ref_transaction_update(transaction, refname,
 				   &new_oid, have_old ? &old_oid : NULL,
+				   NULL, NULL,
 				   update_flags | create_reflog_flag,
 				   msg, &err))
 		die("%s", err.buf);