When viewing an archived version of a document, Permissions appear editable but are not

When viewing a given version of a document, whether in the JSF UI or the WebUI, the Permissions tab/menu is available and appears to be editable (for users with Manage Permissions rights).

Addling a new Local Permission from here will result in a UI slide-in notification (both in JSF and WebUI) confirming "permission added", and the target user will receive an email notification (if this option was selected). However, the ACE is not persisted, and no changes are actually made to the permissions of the document (neither the version in question, nor that document's Working Copy).

Either the Permissions tab should be hidden altogether when viewing versions, or made read-only (or a link to modify the Working Copy's Permissions).