Where are the constants initially defined that are used in the Newsletter Discount (MODULE_ORDER_TOTAL_NEWSLETTER_DISCOUNT_INC_SHIPPING et al)? I have this installed in my 1.5.7d live store and have no errors there, but in my test install (also 1.5.7d, but a newer PHP version), I'm getting an undefined constant warning for each of them where they're called in \ADMIN\modules.php. I've looked in my live installation but don't see them defined anywhere before they're used.
I do see that these are named in a class constructor in /includes/modules/order_table/ot_newsletter_discount.php. But it was my understanding that you could not instantiate a constant that way (or at least that one should not do so). Or is this another of those PHP-version-dependent things? My test install is running 7.4.33 now, and I can't back down to a lower level without also going back to an earlier version of wamp, which I'm reluctant to do.
This is the warning I'm getting (repeated for each of the constants):
[10-May-2023 17:23:56 America/New_York] Request URI: /newnaturals/ADMIN/index.php?cmd=modules&set=ordertotal, IP address: 127.0.0.1
#1 ot_newsletter_discount->__construct() called at [C:\wamp64\www\newnaturals\ADMIN\modules.php:204]
#2 require(C:\wamp64\www\newnaturals\ADMIN\modules.php) called at [C:\wamp64\www\newnaturals\ADMIN\index.php:11]
--> PHP Warning: Use of undefined constant MODULE_ORDER_TOTAL_NEWSLETTER_DISCOUNT_SORT_ORDER - assumed 'MODULE_ORDER_TOTAL_NEWSLETTER_DISCOUNT_SORT_ORDER' (this will throw an Error in a future version of PHP) in C:\wamp64\www\newnaturals\includes\modules\order_total\ot_newsletter_discount.php on line 20.