I had heard about the party_mode bug for the first time at the Koha US conference in Portsmouth. There had been a recent thread in Slack about possible applications of party_mode, which led to the bug being officially filed two days before global bug squashing day.
On Global Bug Squashing day I signed off on a couple bugs and took some time in the afternoon to see if I could write a small patch. Looking into the code I found that someone had conveniently left a comment in the template begging the question [%# FIXME Why that? why not if == 0? %] which turned out to be the answer to the party mode bug. Instead of checking if the value of the attribute, which if party_mode is set to No would be 0 we should check whether the attribute is defined or not.
git log --grep='party_mode'Party mode rules! 🥳