Unable to delete field if previously used in another fieldgroup

[tpr]

I've run into this several times and it seems like a bug, or at least it's misleading.

Steps to reproduce:

1. Add a new template, eg 'news'
2. Set its fieldgroup to another template, eg. 'basic-page'
3. Edit a field that is in 'basic-page' template, and remove from all templates
4. Now you you would assume that you can delete the field because it's not used in any templates, but you can't. Trying to delete from api reveals that it's used by the 'news' template, which obviously shouldn't be true because it uses the fieldgroup of 'basic-page'.

Unfortunately I can't set the 'news' template's fieldgroup to another one because of data loss. I could remove it only via api using fieldgroup->softRemove().

Is there a better way of getting rid of such fields?

[tpr]

Here is the code I have used with Tracy Console to remove fields:

$fieldgroup = wire('fieldgroups')->get('forms');
foreach(array('admin_column_left', 'admin_column_left_END', 'admin_column_right', 'admin_column_right_END') as $ff) {
    if(!$fieldgroup->get($ff)) continue;
    $fieldgroup->softRemove($ff);
    $fieldgroup->save();
    wire('fields')->delete(wire('fields')->get($ff));
}