Fixed the breadcrumb of the object_history template.

NOTE: this could conflict with projects that use django-reversion,
if the `VersionAdmin` is the last in the inheritance chain.

docs/changelog.rst

@@ -8,6 +8,10 @@ Changes in git
 * Fixed Django 1.7 ``changeform_view()`` redirection to the child admin site.
   This fixes custom admin code that uses these views, such as django-reversion_'s ``revision_view()`` / ``recover_view()``.
 * Fixed ``.only('pk')`` field support.
+* Fixed ``object_history_template`` breadcrumb.
+  **NOTE:** when using django-reversion_ / django-reversion-compare_, make sure to implement
+  a ``admin/polymorphic/object_history.html`` template in your project that extends
+  from ``reversion/object_history.html`` or ``reversion-compare/object_history.html`` respectively.
 
 
 Version 0.9 (2016-02-17)

docs/third-party.rst

@@ -12,6 +12,7 @@ However, they require more setup than standard models. That's become:
 * Polymorphic models use `multi-table inheritance <https://docs.djangoproject.com/en/dev/topics/db/models/#multi-table-inheritance>`_.
   See the `reversion documentation <http://django-reversion.readthedocs.org/en/latest/api.html#multi-table-inheritance>`_
   how to deal with this by adding a ``follow`` field for the primary key.
+* Both admin classes redefine ``object_history_template``.
 
 
 Example
@@ -28,14 +29,14 @@ The admin :ref:`admin-example` becomes:
     from .models import ModelA, ModelB, ModelC
 
 
-    class ModelAChildAdmin(PolymorphicChildModelAdmin):
+    class ModelAChildAdmin(PolymorphicChildModelAdmin, VersionAdmin):
         base_model = ModelA
         base_form = ...
         base_fieldsets = (
             ...
         )
 
-    class ModelBAdmin(VersionAdmin, ModelAChildAdmin):
+    class ModelBAdmin(ModelAChildAdmin, VersionAdmin):
         # define custom features here
 
     class ModelCAdmin(ModelBAdmin):
@@ -53,6 +54,19 @@ The admin :ref:`admin-example` becomes:
     revisions.register(ModelC, follow=['modelb_ptr'])
     admin.site.register(ModelA, ModelAParentAdmin)
 
+Redefine a :file:`admin/polymorphic/object_history.html` template, so it combines both worlds:
+
+.. code-block:: html+django
+
+    {% extends 'reversion/object_history.html' %}
+    {% load polymorphic_admin_tags %}
+
+    {% block breadcrumbs %}
+        {% breadcrumb_scope base_opts %}{{ block.super }}{% endbreadcrumb_scope %}
+    {% endblock %}
+
+This makes sure both the reversion template is used, and the breadcrumb is corrected for the polymorphic model.
+
 .. _django-reversion-compare-support:
 
 django-reversion-compare support