-sub record_gdrlast ($$) {
- my ($gdrlast, $newvalue) = @_;
- push @deferred_updates, "update $gdrlast $newvalue $git_null_obj";
+sub record_gdrlast ($$;$) {
+ my ($gdrlast, $newvalue, $oldvalue) = @_;
+ $oldvalue ||= $git_null_obj;
+ push @deferred_updates, "update $gdrlast $newvalue $oldvalue";