packed_refs_lock(): report errors via a `struct strbuf *err`

That way the callers don't have to come up with error messages
themselves.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/refs/packed-backend.h b/refs/packed-backend.h
index dbc00d339..210e3f35c 100644
--- a/refs/packed-backend.h
+++ b/refs/packed-backend.h
@@ -6,10 +6,10 @@ struct ref_store *packed_ref_store_create(const char *path,
 
 /*
  * Lock the packed-refs file for writing. Flags is passed to
- * hold_lock_file_for_update(). Return 0 on success. On errors, set
- * errno appropriately and return a nonzero value.
+ * hold_lock_file_for_update(). Return 0 on success. On errors, write
+ * an error message to `err` and return a nonzero value.
  */
-int packed_refs_lock(struct ref_store *ref_store, int flags);
+int packed_refs_lock(struct ref_store *ref_store, int flags, struct strbuf *err);
 
 void add_packed_ref(struct ref_store *ref_store,
 		    const char *refname, const struct object_id *oid);