change request and simplified test

Author: jo-pol

src/main/java/edu/harvard/iq/dataverse/DataverseConverter.java

@@ -26,9 +26,12 @@ public class DataverseConverter implements Converter {
 
     @Override
     public Object getAsObject(FacesContext facesContext, UIComponent component, String submittedValue) {
-        var pk = (submittedValue == null || submittedValue.isEmpty() || submittedValue.matches(".*[^0-9].*"))
-        ? 0 : Long.valueOf(submittedValue);
-        return dataverseService.find(pk);
+        if (submittedValue == null || !submittedValue.matches("[0-9]+")) {
+            return dataverseService.findRootDataverse();
+        }
+        else {
+            return dataverseService.find(Long.valueOf(submittedValue));
+        }
         //return dataverseService.findByAlias(submittedValue);
     }