Please allow ifnull() to work with boolean data types.
In general, please treat booleans like first class datatypes.
Here is a use case, say you have a boolean valued field (or calculated field) that is sometimes null. Then you want to give it a default value of say false. Or you want to test if it is always true, but don't want to ignore nulls. Say you want to know if the condition is satisfied for every data row treating null as not satisfied (same as false)
You should be able to say ifnull(my_field, false)
or min(ifnull(my_field, false)) which will be true if and only if my_field is true for every single record
Instead you get an error asking whether you meant to use ifnull() with integers instead of boolean.