rename a file if it gets restored so that it no longer exists as a version. Otherwise it can happen that the expire() function removes all other versions so that we end up with only one version which is exactly the same as the original file

apps/files_versions/lib/versions.php

@@ -200,7 +200,7 @@ class Storage {
 			}
 
 			// rollback
-			if( @$users_view->copy('files_versions'.$filename.'.v'.$revision, 'files'.$filename) ) {
+			if( @$users_view->rename('files_versions'.$filename.'.v'.$revision, 'files'.$filename) ) {
 				$files_view->touch($file, $revision);
 				Storage::expire($file);
 				return true;