Person:+editircnicknames has strange and inconsistent error handling

Copy-paste from IRC with reporter's permission:

<Diziet> It offered me one box for network and one for nick. I typed something with a comma and a space (two networks) into the LH box and Diziet into the RH box. It then complained that the box can't be blank.
<Diziet> I thought "it is confused I will try one network only" so put irc.oftc.net Diziet.
<Diziet> Then it complained that the box can't be blank and showed me two lots of boxese, one with my comma-containing input, and one which was a pair of blank boxes.
<Diziet> This is from memory. I was trying to do something else at the time.
<Diziet> I was able to fix it by repeatedly typing the right things in and hitting save. Eventually it reached a fixed point of correct view with no error.