[2.0.x] Used a separate admin site for autocomplete tests.

Backport of 474bd7a5 from master

tests/admin_views/test_autocomplete_view.py

 import json
 
 from django.contrib import admin
-from django.contrib.admin import site
 from django.contrib.admin.tests import AdminSeleniumTestCase
 from django.contrib.admin.views.autocomplete import AutocompleteJsonView
 from django.contrib.auth.models import Permission, User
@@ -30,6 +29,7 @@ class BookAdmin(admin.ModelAdmin):
     inlines = [AuthorshipInline]
 
 
+site = admin.AdminSite(name='autocomplete_admin')
 site.register(Question, QuestionAdmin)
 site.register(Answer, AnswerAdmin)
 site.register(Author, AuthorAdmin)
@@ -39,7 +39,7 @@ site.register(Book, BookAdmin)
 class AutocompleteJsonViewTests(AdminViewBasicTestCase):
     as_view_args = {'model_admin': QuestionAdmin(Question, site)}
     factory = RequestFactory()
-    url = reverse_lazy('admin:admin_views_question_autocomplete')
+    url = reverse_lazy('autocomplete_admin:admin_views_question_autocomplete')
 
     @classmethod
     def setUpTestData(cls):
@@ -156,12 +156,12 @@ class SeleniumTests(AdminSeleniumTestCase):
         self.superuser = User.objects.create_superuser(
             username='super', password='secret', email='super@example.com',
         )
-        self.admin_login(username='super', password='secret', login_url=reverse('admin:index'))
+        self.admin_login(username='super', password='secret', login_url=reverse('autocomplete_admin:index'))
 
     def test_select(self):
         from selenium.webdriver.common.keys import Keys
         from selenium.webdriver.support.ui import Select
-        self.selenium.get(self.live_server_url + reverse('admin:admin_views_answer_add'))
+        self.selenium.get(self.live_server_url + reverse('autocomplete_admin:admin_views_answer_add'))
         elem = self.selenium.find_element_by_css_selector('.select2-selection')
         elem.click()  # Open the autocomplete dropdown.
         results = self.selenium.find_element_by_css_selector('.select2-results')
@@ -196,7 +196,7 @@ class SeleniumTests(AdminSeleniumTestCase):
     def test_select_multiple(self):
         from selenium.webdriver.common.keys import Keys
         from selenium.webdriver.support.ui import Select
-        self.selenium.get(self.live_server_url + reverse('admin:admin_views_question_add'))
+        self.selenium.get(self.live_server_url + reverse('autocomplete_admin:admin_views_question_add'))
         elem = self.selenium.find_element_by_css_selector('.select2-selection')
         elem.click()  # Open the autocomplete dropdown.
         results = self.selenium.find_element_by_css_selector('.select2-results')

tests/admin_views/urls.py

 from django.conf.urls import include, url
 
 from . import admin, custom_has_permission_admin, customadmin, views
+from .test_autocomplete_view import site as autocomplete_site
 
 urlpatterns = [
     url(r'^test_admin/admin/doc/', include('django.contrib.admindocs.urls')),
@@ -15,4 +16,5 @@ urlpatterns = [
     # All admin views accept `extra_context` to allow adding it like this:
     url(r'^test_admin/admin8/', (admin.site.get_urls(), 'admin', 'admin-extra-context'), {'extra_context': {}}),
     url(r'^test_admin/has_permission_admin/', custom_has_permission_admin.site.urls),
+    url(r'^test_admin/autocomplete_admin/', autocomplete_site.urls),
 ]