Assigning already assigned user through quick action fails
When a user is already assigned to an issue or an MR, and you try to assign this user through a quick action, the comment submission fails with a 500 error.
Steps to reproduce
- Create an issue
- Assign a user, e.g. @toupeira
- Post a comment with
What is the current bug behavior?
The comment submission fails.
If the comment is part of an MR review draft, the whole publishing process fails midway (this might warrant S2?)
What is the expected correct behavior?
The comment should be posted, and the quick action should be ignored.
Relevant logs and/or screenshots
Frontend shows an error:
Backend raises a
ActiveRecord::RecordNotUnique exception: https://sentry.gitlab.net/gitlab/gitlabcom/issues/974515/
Output of checks
This bug happens on GitLab.com