Notice: Undefined index: flag_fetch_node_by_user

On first install, I got the following notice:

Notice: Undefined index: flag_fetch_node_by_user in flag_rules_action_info() (line 380 of /.../sites/all/modules/contrib/flag/flag.rules.inc).
Notice: Undefined index: label in flag_rules_action_info() (line 381 of /.../sites/all/modules/contrib/flag/flag.rules.inc).

That looks like a legacy array index with no check for existence before referencing it. Line 380 of flag.rules.inc:

<?php
    $items['flag_fetch_entity_by_user'] = $items['flag_fetch_node_by_user'];
?>

I've added a test for existence and I'm submitting a patch.