Modeladmin handles notification to the user if a model instance has protected ForeignKey
relationships. However, if the protected relation is a OneToOneField it raises an exception:
File ".../wagtail/wagtail/contrib/modeladmin/views.py", line 742, in post
for obj in qs.all():
AttributeError: 'MyRelatedModel' object has no attribute 'all'
because qs in this case is the related instance rather than a queryset of related instances
(as is the case for a ForeignKey).
This commit handles the OneToOneField case as well.
This hook mimics the functiolity provided by `construct_page_action_menu`
in that it constructs the final list of buttons to be shown in the wagtail
admin interface. This means that within this function button's can be
removed, added or re-ordered.
See #4925
Neal Todd