Steps:
- Create a recuring event starting on monday, daily for 6 times.
- Select the occurrence on Friday and delete it (only this occurrence)
- Edit Tuesdays event, change subject and choose to apply changes to ALL events in a series.
Result: Friday's occurence reappears.
Expected: Friday's occurence is still invisible.
Note: There will be no issue if in point 3 you edit the first event in a series.