Fixed #25324 -- Registered ModelAdmin instances with @admin.register decorator

django/contrib/auth/admin.py

@@ -24,6 +24,7 @@ csrf_protect_m = method_decorator(csrf_protect)
 sensitive_post_parameters_m = method_decorator(sensitive_post_parameters())
 
 
+@admin.register(Group)
 class GroupAdmin(admin.ModelAdmin):
     search_fields = ('name',)
     ordering = ('name',)
@@ -39,6 +40,7 @@ class GroupAdmin(admin.ModelAdmin):
             db_field, request=request, **kwargs)
 
 
+@admin.register(User)
 class UserAdmin(admin.ModelAdmin):
     add_form_template = 'admin/auth/user/add_form.html'
     change_user_password_template = None
@@ -196,6 +198,3 @@ class UserAdmin(admin.ModelAdmin):
             request.POST['_continue'] = 1
         return super(UserAdmin, self).response_add(request, obj,
                                                    post_url_continue)
-
-admin.site.register(Group, GroupAdmin)
-admin.site.register(User, UserAdmin)

django/contrib/flatpages/admin.py

@@ -4,6 +4,7 @@ from django.contrib.flatpages.models import FlatPage
 from django.utils.translation import ugettext_lazy as _
 
 
+@admin.register(FlatPage)
 class FlatPageAdmin(admin.ModelAdmin):
     form = FlatpageForm
     fieldsets = (
@@ -16,5 +17,3 @@ class FlatPageAdmin(admin.ModelAdmin):
     list_display = ('url', 'title')
     list_filter = ('sites', 'registration_required')
     search_fields = ('url', 'title')
-
-admin.site.register(FlatPage, FlatPageAdmin)

django/contrib/redirects/admin.py

@@ -2,10 +2,9 @@ from django.contrib import admin
 from django.contrib.redirects.models import Redirect
 
 
+@admin.register(Redirect)
 class RedirectAdmin(admin.ModelAdmin):
     list_display = ('old_path', 'new_path')
     list_filter = ('site',)
     search_fields = ('old_path', 'new_path')
     radio_fields = {'site': admin.VERTICAL}
-
-admin.site.register(Redirect, RedirectAdmin)

django/contrib/sites/admin.py

@@ -2,8 +2,7 @@ from django.contrib import admin
 from django.contrib.sites.models import Site
 
 
+@admin.register(Site)
 class SiteAdmin(admin.ModelAdmin):
     list_display = ('domain', 'name')
     search_fields = ('domain', 'name')
-
-admin.site.register(Site, SiteAdmin)