JIRA does not prevent setting Reporter to a Request Participant

Summary

While JIRA will stop you from setting the Request Participant field to include the Reporter, it does not appear to enforce the same restriction when setting the Reporter.

Steps to Reproduce

1. Raise a request from customer1
2. Add customer2 as a request participant
3. Change the Reporter to customer2

Expected Results

A warning similar to that given when trying to set the Request Participant to include the Reporter, and the action to be blocked.

Image copied from JSDSERVER-5112

Actual Results

The reporter and request participant are set to the same user, giving rise to other known issues (e.g. Having the same user as reporter and request participants leaves the issue not transitionable through customer portal)

Workaround

Manually update the field(s) to avoid having the same user as both Reporter and Participant.