Forum OpenACS Q&A: problems updating an ad_form checkbox where all checkbox items are emtpy

It appears that if you unselect all options when updating a multiple valued checkbox via ad_form, the form variable does not get set when you hit submit (which is what you would expect); however, the variable's value in the -edit_data scope contains the previous value.

What is the proper way to handle this case with ad_form, or is this a bug in 5.0?