It occurred to me that printing a blank cart and throwing a bunch of errors out wasn't what the cart printing sub was supposed to do...so I checked: I had a conditional set up to avoid it if there was no cart, but *it didn't check if the cart was empty*, just that there was a name set for the cart in the session ID.
Hm. Maybe I remember what this does okay after all...
Anyway, I sat back and, after maybe five minutes, figured I should just add
&& (keys %cart)
to the conditional that read
and it worked.
I know that's not a big deal...but it's a big deal for me, right now, in this code. So I'll be happy about it, and have some more coffee.