1 files changed, 12 insertions, 0 deletions
diff --git a/refs.c b/refs.c
index 989462c972..f8f41ffb04 100644
--- a/refs.c
+++ b/refs.c
@@ -1694,6 +1694,18 @@ int ref_transaction_commit(struct ref_transaction *transaction,
 {
 	struct ref_store *refs = transaction->ref_store;
 
+	switch (transaction->state) {
+	case REF_TRANSACTION_OPEN:
+		/* Good. */
+		break;
+	case REF_TRANSACTION_CLOSED:
+		die("BUG: prepare called on a closed reference transaction");
+		break;
+	default:
+		die("BUG: unexpected reference transaction state");
+		break;
+	}
+
 	if (getenv(GIT_QUARANTINE_ENVIRONMENT)) {
 		strbuf_addstr(err,
 			      _("ref updates forbidden inside quarantine environment"));