1. Open the attached project
2. Open the Test Runner
3. Double click on TestImportAsset test (it works)
4. Make any changes to the scene
5. Double click on TestImportAsset test
6. Press Cancel when asked to save a scene
7. Double click on TestImportAsset test

Actual result: The test is not run after double click anymore.
Expected result: The test should be run after double click.

Reproducible with: 2018.2.0a1, 2018.1.0b9, 2018.1.0a4, 2017.3.1p1, 2017.3.0b9, 2017.2.1p4, 2017.2.1p1, 2017.1.3p1.
Regression introduced in: 2018.1.0a4, 2017.3.0b9, 2017.2.1p1, 2017.1.3p1.
Not reproducible with: 2018.1.0a3, 2017.3.0b8, 2017.2.1f1, 2017.1.3f1, 5.6.5f1.

Note: tests can still be run by RMB > Run.

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fixed in 2018.2.0a9.