I introduced a WRN message if you call a function on NULL. This is the equivalent of obj->my_call() which would crash or raise an exception in pretty much languages. Not seeing those invalid calls can make it harder to debug complex apps.
EFL UI Focus has a lot of calls like this. Check the commit a92186be6ab7ba6b8ba0b2bedeaec51dcb4a3898 to verify that the null checks are good, or maybe the logic is really broken and needs fixing. Also, fix any remaining call to NULL. :)