"Quiz Results: Quiz State" filter must be exposed to work correctly

Summary: when adding a "Quiz Results: Quiz State" filter in a quiz view the returned results are incorrectly filtered to show only the quizzes in the "Finished" state.

To replicate: have some quizzes in various states (like In Progress and Finished) and create a new view (of type "Quiz"). Add some fields (like Quiz Node NID and Quiz State). Make the display style a table, and hit "Preview." You should see a list of quizzes - some of which are In Progress and some of which are Finished (question: should quizzes that are in the state "Not started" also show up here?).

Now add a "Quiz Results: Quiz State" filter and set the Quiz State filtering option to "All Results (Do not filter)".

Expected result: no change change in the listed quizzes.

Actual result: only the Quizzes which have the state "Finished" are listed - the quizzes with the state "In Progress" disappear from the view.

Due to this bug, it's impossible to view a list of quizzes which a particular user has not taken (is this possible?).