Custom field checkbox will not clear if no checkboxes should be selected

[jamjarae]

Version v8.1.16 - build 18612

I added a checkbox with three items in it and tested it with one asset, which was fine except this asset has none of those options so I cleared all the ticks, saved the asset and found it hadn't removed any of them. I found if at least one is ticked, it saves but if none are ticked, it keeps the last selection. This seems to be an oversite, I've added a None option but that's not really a fix.

[restena-sw]

Only partly related, but maybe worth cross-checking in the code: we made an unfortunate choice for checkbox labels in that we assigned the strings "true" and "false". This "worked" prior to our 6.2 -> 8.0 upgrade, the values ended up in MySQL as 0 and 1 (some implicit type conversion into boolean/tinyint(1) instead of the actual strings? and were retrieved and editable with their string names in UI still.

Since the upgrade, we cannot edit any assets with this custom field at all. The create/edit page complains about " contains invalid options."

You can check any combination of checkboxes, none get saved.

As soon as I renamed the options to "FullDepth" and "NotFullDepth", they get stored as the strings that they are, and can be set at will.

The original bug as described by OP still stands, also in our current 8.1.18 : UNsetting all checkboxes and then saving keeps the previous state.