Restrict users who can be added to a project

[Felix]

Hello everyone,

I'm looking for a solution to restrict the users which can be added to a project role. Either an addon, a built in solution, or maybe a groovy script/custom plugin. 

Let's assume the following scenario: The JIRA Instance is used by developers, marketing and customers. Each one has their own group. Marketing and Customers work in a shared project which is hidden from the developers. The developers are working in their own project, hidden from marketing and customers. Permissions for those projects are generally granted based on group memberships. So far so good, the dev's don't see the marketing project and the other way round. However, there is a situation: there are 2 persons called Jane Doe, the admin of the dev-project doesn't take a close look and just adds the first Jane Doe popping up in the "add users to a role" dialogue. Unfortunately this Jane Doe is not the "Dev-Jane" but the "Customer-Jane" who now gets insights on the confidential project internals. 

Is there a way to prevent users which are or are not part of a group to show up in the user picker in the project settings? 

I know I could work around by setting the issue security level to the group, so the "wrong" user would see the project but not the actual issues. However I'm looking for a more sufficient solution.

Thank you! Cheers!

[Nic Brough -Adaptavist-]

There is no way to restrict this.