Open or Closed Issues filter seems to be busted

[Cheddam]

If I search for "example", I currently get the following number of results:

• With "Open Issues": 489
• With "Closed Issues": 1167
• With "Open or Closed Issues": 9556

A pesky little undefined is making it into the query for "Open or Closed", where a is:closed or is:open would be otherwise. I'd expect the Open or Closed total to equal the Open + Closed totals.