Selection of tests broken for Qt Test

The selection of test for execution of "Tools => Tests => Run Selected Tests" does not work.

In the Test panel I removed the check of test_case3 with the result, that the TestMyC1 and Qt Test were deselected instead of the tristate of part selection!

Running All Tests works.

 The interaction is shown in this little movie. Have a closer look at the Tristate of Qt Test and TestMyC1:

ManualTestSelection.mp4