Validation of Pool size input fields on Datasource Setup screen comes with these two messages:
1) All fields must be filled in.
2) Values for pool sizes must be numeric.

Passing String value into Min Pool Size gives me 1), 2) is correct in this case.
Using empty Max Pool Size gives me 2), 1) is correct in this case.

Min pool size always use 1) as validation error message.
Max pool size always use 2) as validation error message.

Pool size validation should be fixed to always use 1) if the field is empty, and 2) if the value passed by user is not numeric.