Can't filter on empty/non-empty fields in CiviReport

[JonGold]

I had a client come to me with a question - they have a custom participant field "Special Needs" which is a Note.

They were attempting to create a report to show non-empty Special Needs - but the filter operator in CiviReport "is not empty" is actually "IS NOT NULL" on the SQL end.  Since Note fields are created by default as empty, not NULL, this filter fails.

Is there a reason we couldn't do something similar to the work done in Search Builder[1] so that CiviReport builds the SQL statement to include empty fields as well as null fields when filtering?

[1] https://issues.civicrm.org/jira/browse/CRM-10549