The tests that was open in Text Editor and then closed disappear from Test pane after clicking 'Rescan Tests'.

To reproduce this bug:

1. Download and unzip QtTest_rescan_tests_bug.zip
2. Open project utility.pro in QtCreator
3. In Tests pane there should be visible 3 Qt Tests: Test1Test, Test2Test and Test3Test
4. Open tst_test1test.cpp, tst_test2test.cpp, tst_test3test.cpp files in Text Editor
5. Close tst_test1test.cpp file - there should be 2 open files in Open Documents pane
6. Now in Tests pane right click and select 'Rescan Tests' - this causes the Test1Test to disapear from Tests pane
7. Now reopen tst_test1test.cpp file - this will refresh the Test pane and Test1test will be visible again
8. Now close all files and click 'Rescan tests' - this causes all test to disapear.