We have a few different APIs for plugins to reject some but not all of the changes that can occur with refs - merge checks, pre-receive hooks, etc.

Ideally there would be a single way for plugins to reject any and all changes to a ref.

Possible solution

Introduce a RepositoryRefsChangeRequestedEvent interface and AbstractRepositoryRefsChangeRequestedEvent abstract class

• We would fire this event anywhere that a ref is changed (and plugins would be required to do the same when they update a ref).
• Any plugin could listen to this to prevent any ref change within Stash, regardless of whether it's from a push, merge, branch creation, etc.