1 files changed, 4 insertions, 1 deletions
diff --git a/refs.h b/refs.h
index 8c7f9c44dc..09d3564116 100644
--- a/refs.h
+++ b/refs.h
@@ -269,9 +269,12 @@ void ref_transaction_delete(struct ref_transaction *transaction,
  * Commit all of the changes that have been queued in transaction, as
  * atomically as possible.  Return a nonzero value if there is a
  * problem.
+ * If err is non-NULL we will add an error string to it to explain why
+ * the transaction failed. The string does not end in newline.
  */
 int ref_transaction_commit(struct ref_transaction *transaction,
-			   const char *msg, enum action_on_err onerr);
+			   const char *msg, struct strbuf *err,
+			   enum action_on_err onerr);
 
 /*
  * Free an existing transaction and all associated data.