There are problems when the Assigned To field is set, but the issue tracker is not set to assigned. A non-member can set the Assigned-To field even when they don't have permission to make the issue assigned. The issue then shows up in the assignee's "Issues assigned to me" area even when it has not been officially assigned.

Note that others struggle with this issue as well. See also #349, #640, and #1919.

I can think of a few potential solutions:

Hide the Assigned-to field and show it only when the issue is assigned.¶

Prevent a New issue from getting an assignment at all.¶

Make the availability of the form field depend on user permission for Assignment in the workflow.¶

Add new permissions for the Assigned-To field (and perhaps others as mentioned in #1919) so that non-members can be denied the ability to change it.¶