On the first request served by a PHP process, a Drupal 6 or 7 hook that was invoked with
module_invoke()before it had been invoked by
module_invoke_all()could have its module name reported as an empty string. This has been fixed.
On PHP 7.0 and 7.1, a Drupal 6 or 7 hook invoked via
module_invoke_all()could report the module name as an empty string in some situations. This has been fixed.