JSF 2.3 - The f:viewParam BV/event fail has been fixed in JSF 2.3

The standard UIViewParameter implementation uses in JSF 2.0-2.2 an internal "is required" check when the submitted value is null, hereby completely bypassing the standard UIInput validation, including any bean validation annotations and even the PreValidateEvent and PostValidateEvent events. This is not desired. The workaround was added in OmniFaces 2.0. In JSF 2.3, this has been fixed and has only effect when javax.faces.INTERPRET_EMPTY_STRING_SUBMITTED_VALUES_AS_NULL context parameter is set to true.