refs.c: change ref_transaction_update() to do error checking and return status

diff --git a/refs.h b/refs.h
index 163b45c50aa36b3438012836ded62993d06c73c6..c5376cee8d84f94ad2e08ce5baae7537e9d4a47a 100644 (file)
--- a/refs.h
+++ b/refs.h
@@ -246,12 +246,16 @@ struct ref_transaction *ref_transaction_begin(void);
  * be deleted.  If have_old is true, then old_sha1 holds the value
  * that the reference should have had before the update, or zeros if
  * it must not have existed beforehand.
+ * Function returns 0 on success and non-zero on failure. A failure to update
+ * means that the transaction as a whole has failed and will need to be
+ * rolled back. On failure the err buffer will be updated.
  */
-void ref_transaction_update(struct ref_transaction *transaction,
-                           const char *refname,
-                           const unsigned char *new_sha1,
-                           const unsigned char *old_sha1,
-                           int flags, int have_old);
+int ref_transaction_update(struct ref_transaction *transaction,
+                          const char *refname,
+                          const unsigned char *new_sha1,
+                          const unsigned char *old_sha1,
+                          int flags, int have_old,
+                          struct strbuf *err);
 
 /*
  * Add a reference creation to transaction.  new_sha1 is the value