From 199a02d1e2adef39b6346a254b097c9ac64a9ec4 Mon Sep 17 00:00:00 2001
From: Joseph Gordon <j.gordon.matthew@gmail.com>
Date: Sat, 25 Jul 2015 20:15:50 -0500
Subject: [PATCH] Fixed #25110 -- Fixed a test_runner test isolation
 regression.

Thanks claudep for the patch.
---
 tests/test_runner/test_discover_runner.py | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/tests/test_runner/test_discover_runner.py b/tests/test_runner/test_discover_runner.py
index 70117f0327..dc82c24ecf 100644
--- a/tests/test_runner/test_discover_runner.py
+++ b/tests/test_runner/test_discover_runner.py
@@ -121,9 +121,11 @@ class DiscoverRunnerTest(TestCase):
         """
         Tests shouldn't be discovered twice when discovering on overlapping paths.
         """
-        single = DiscoverRunner().build_suite(["gis_tests"]).countTestCases()
-        dups = DiscoverRunner().build_suite(
-            ["gis_tests", "gis_tests.geo3d"]).countTestCases()
+        base_app = 'gis_tests'
+        sub_app = 'gis_tests.geo3d'
+        with self.modify_settings(INSTALLED_APPS={'append': sub_app}):
+            single = DiscoverRunner().build_suite([base_app]).countTestCases()
+            dups = DiscoverRunner().build_suite([base_app, sub_app]).countTestCases()
         self.assertEqual(single, dups)
 
     def test_reverse(self):