Negate option not being checked

Problem/Motivation

We're using this with the entity_extra_field module.

I need the condition to evaluate if a boolean field is TRUE. There is a check to see if a field is empty, or null, but since there's no explicit check to see if it's TRUE I used the "negate" option.

The field shows only when the value of the field is FALSE, it appears as if the negation isn't being checked.

Steps to reproduce

• Add an extra field to a node with a boolean field
• Edit the extra field entity condition to check for the field IS EMPTY.
• Click "Negate"

Proposed resolution

Evaluate seems to need to return:
return $this->isNegated() ? !$verdict : $verdict;