Fixed #33264 -- Made test runner return non-zero error code for unexpected successes.

tests/test_runner_apps/failures/tests_failures.py

@@ -0,0 +1,23 @@
+from unittest import TestCase, expectedFailure
+
+
+class FailureTestCase(TestCase):
+    def test_sample(self):
+        self.assertEqual(0, 1)
+
+
+class ErrorTestCase(TestCase):
+    def test_sample(self):
+        raise Exception('test')
+
+
+class ExpectedFailureTestCase(TestCase):
+    @expectedFailure
+    def test_sample(self):
+        self.assertEqual(0, 1)
+
+
+class UnexpectedSuccessTestCase(TestCase):
+    @expectedFailure
+    def test_sample(self):
+        self.assertEqual(1, 1)