After renaming an user, if you search for reporter or assignee the "Basic" search is disabled

Summary

Basic search is unavailable when performing simple JQL searches involving users who have been renamed in the past. This effects both searching from a saved filter or from a gadget on a dashboard which may have previously worked.

Steps to Reproduce

1. Create a user with any username
2. Browse to the issue navigator and search for this user either in the "reporter" or "assignee" field
3. You will be able to search either in Basic or Advanced mode
4. Now rename this user with any value (adding an extra letter will work)
5. Browse back to the issue navigator and, in Advanced mode, search for the user either in the "reporter" or "assignee" field
6. The "Basic" search will be disabled
7. If you hover over the "Basic" link, the message "This query is too complex to display in Simple mode" will be shown

Expected Results

You should be able to switch between Basic and Advanced mode

Actual Results

The Basic search is disabled and if you hover over the "Basic" link, the message "This query is too complex to display in Simple mode" will be shown

Notes

If you are unsure whether a username has changed run the following SQL:

select * from app_user where lower_user_name='<username>'

and it will return the current and previous username

Workaround

Rename the user back to the original username, or use advanced search instead