CSV Import will automatically include user to the Developers Role whether it is exist or not

Steps to Reproduce:

1. Delete the Developers Role from JIRA.
2. Confirm to delete the role when being reminded.
3. The permission scheme will remove Developers role from the permissions.
4. Create a Test Project.
5. Navigate to JIRA Administration > System > External System Import and choose CSV Import.
6. Import the AtlassianTestCSV (1).csv and choose the previous Test project as the target project.
7. Finish the Import.

Expected Result:
The issue is imported without any problem and the assignee field will used what have been specified in the CSV file.

Actual Result:
Same as the expected result above, but will be creating the Developers Role in the process and included those users inside.

Notes:
While the user who are assigned to those issue will stays even without having "Assignable User" permission, the user would be included in the Developers Role which also does not have the permission.

This should not be a problem if there is only several user on the CSV file, but if importing hundred of issues with unique users could lead to a problem where it would not possible to access Project People/Roles due to amount of users in that role.

Workaround

The issue only replicates on CSV importer via the External System Import. Use the non-admin CSV importer in the Jira search page.