_if gives an unexpected error if a clause is empty

(Bug, Closed -> Fixed, Priority: Critical, Test Status: Unit tested , Reported By Bad Link: Thing 3y284of not found, )
QL, Errors
Summary: I had some code using
if(isEmpty(<foo>),xxx,<bar>)
'Xxx' was just a placeholder for while I worked on getting foo and bar correct. Once 'xxx' was displaying when expected, O tried removing it, leaving:
if(isEmpty(<foo>),,<bar>)
When I tried refreshing my test Event, I got a vague message about an unexpected error being logged.
I wouldn't be at all surprised if what I tried there is not meant to be supported. If so, consider this another case of "error messages could use improvement."