1 files changed, 32 insertions, 11 deletions
diff --git a/refs.c b/refs.c
index 0c1e45f5a9..dd0d9c360f 100644
--- a/refs.c
+++ b/refs.c
@@ -914,7 +914,7 @@ int refs_delete_ref(struct ref_store *refs, const char *msg,
 	transaction = ref_store_transaction_begin(refs, &err);
 	if (!transaction ||
 	    ref_transaction_delete(transaction, refname, old_oid,
-				   flags, msg, &err) ||
+				   NULL, flags, msg, &err) ||
 	    ref_transaction_commit(transaction, &err)) {
 		error("%s", err.buf);
 		ref_transaction_free(transaction);
@@ -1238,43 +1238,57 @@ int ref_transaction_update(struct ref_transaction *transaction,
 int ref_transaction_create(struct ref_transaction *transaction,
 			   const char *refname,
 			   const struct object_id *new_oid,
+			   const char *new_target,
 			   unsigned int flags, const char *msg,
 			   struct strbuf *err)
 {
-	if (!new_oid || is_null_oid(new_oid)) {
-		strbuf_addf(err, "'%s' has a null OID", refname);
+	if (new_oid && new_target)
+		BUG("create called with both new_oid and new_target set");
+	if ((!new_oid || is_null_oid(new_oid)) && !new_target) {
+		strbuf_addf(err, "'%s' has neither a valid OID nor a target", refname);
 		return 1;
 	}
 	return ref_transaction_update(transaction, refname, new_oid,
-				      null_oid(), NULL, NULL, flags,
+				      null_oid(), new_target, NULL, flags,
 				      msg, err);
 }
 
 int ref_transaction_delete(struct ref_transaction *transaction,
 			   const char *refname,
 			   const struct object_id *old_oid,
-			   unsigned int flags, const char *msg,
+			   const char *old_target,
+			   unsigned int flags,
+			   const char *msg,
 			   struct strbuf *err)
 {
 	if (old_oid && is_null_oid(old_oid))
 		BUG("delete called with old_oid set to zeros");
+	if (old_oid && old_target)
+		BUG("delete called with both old_oid and old_target set");
+	if (old_target && !(flags & REF_NO_DEREF))
+		BUG("delete cannot operate on symrefs with deref mode");
 	return ref_transaction_update(transaction, refname,
 				      null_oid(), old_oid,
-				      NULL, NULL, flags,
+				      NULL, old_target, flags,
 				      msg, err);
 }
 
 int ref_transaction_verify(struct ref_transaction *transaction,
 			   const char *refname,
 			   const struct object_id *old_oid,
+			   const char *old_target,
 			   unsigned int flags,
 			   struct strbuf *err)
 {
-	if (!old_oid)
-		BUG("verify called with old_oid set to NULL");
+	if (!old_target && !old_oid)
+		BUG("verify called with old_oid and old_target set to NULL");
+	if (old_oid && old_target)
+		BUG("verify called with both old_oid and old_target set");
+	if (old_target && !(flags & REF_NO_DEREF))
+		BUG("verify cannot operate on symrefs with deref mode");
 	return ref_transaction_update(transaction, refname,
 				      NULL, old_oid,
-				      NULL, NULL,
+				      NULL, old_target,
 				      flags, NULL, err);
 }
 
@@ -2485,7 +2499,7 @@ int refs_delete_refs(struct ref_store *refs, const char *logmsg,
 
 	for_each_string_list_item(item, refnames) {
 		ret = ref_transaction_delete(transaction, item->string,
-					     NULL, flags, msg, &err);
+					     NULL, NULL, flags, msg, &err);
 		if (ret) {
 			warning(_("could not delete reference %s: %s"),
 				item->string, err.buf);
@@ -2595,7 +2609,7 @@ static int migrate_one_ref(const char *refname, const struct object_id *oid,
 		if (ret < 0)
 			goto done;
 	} else {
-		ret = ref_transaction_create(data->transaction, refname, oid,
+		ret = ref_transaction_create(data->transaction, refname, oid, NULL,
 					     REF_SKIP_CREATE_REFLOG | REF_SKIP_OID_VERIFICATION,
 					     NULL, data->errbuf);
 		if (ret < 0)
@@ -2878,3 +2892,10 @@ done:
 	strbuf_release(&new_gitdir);
 	return ret;
 }
+
+int ref_update_expects_existing_old_ref(struct ref_update *update)
+{
+	return (update->flags & REF_HAVE_OLD) &&
+		(!is_null_oid(&update->old_oid) || update->old_target);
+}
+