Merge branch 'kn/reflog-migration'

"git refs migrate" learned to also migrate the reflog data across
backends.

* kn/reflog-migration:
  refs: mark invalid refname message for translation
  refs: add support for migrating reflogs
  refs: allow multiple reflog entries for the same refname
  refs: introduce the `ref_transaction_update_reflog` function
  refs: add `committer_info` to `ref_transaction_add_update()`
  refs: extract out refname verification in transactions
  refs/files: add count field to ref_lock
  refs: add `index` field to `struct ref_udpate`
  refs: include committer info in `ref_update` struct

diff --cc refs.c
Simple merge

diff --cc refs.h
Simple merge

diff --cc refs/files-backend.c
index 467fe347fa7e7d82ed7a2836e43ea749bb90ad7d,8953d1c6d37b13b0db701888b3db92fd87a68aaa..5cfb8b7ca8678e171b8e8a7ad6daf1af74a81b59
--- 1/refs/files-backend.c
--- 2/refs/files-backend.c
+++ b/refs/files-backend.c
@@@ -2533,9 -2539,15 +2543,15 @@@ static int check_old_oid(struct ref_upd
                            oid_to_hex(oid),
                            oid_to_hex(&update->old_oid));
  
 -      return -1;
 +      return ret;
  }
  
+ struct files_transaction_backend_data {
+       struct ref_transaction *packed_transaction;
+       int packed_refs_locked;
+       struct strmap ref_locks;
+ };
+ 
  /*
   * Prepare for carrying out update:
   * - Lock the reference referred to by update.

diff --cc refs/refs-internal.h
Simple merge

diff --cc refs/reftable-backend.c
Simple merge