Fix Windows task and certificate collector reliability

tests/test_scoring.py

@@ -20,6 +20,17 @@ def scored(result):
 
 
 class ScoringRegressionTests(unittest.TestCase):
+    def test_task_and_certificate_failures_reduce_coverage_without_risk(self):
+        data = fixture('clean_windows')
+        baseline = assess(data)
+        for name, status in [('tasks', 'failed'), ('certificates', 'partial')]:
+            data['checks'][name]['status'] = status
+            data['checks'][name]['errors'] = [{'code': 'collection_failed', 'scope': name, 'message': 'Sanitized failure'}]
+        result = assess(data)
+        self.assertEqual(result['score'], baseline['score'])
+        self.assertLess(result['coverage']['percent'], baseline['coverage']['percent'])
+        self.assertEqual(result['confidence']['level'], 'moderate')
+
     def test_required_scenarios(self):
         expected = {'clean_windows':0,'inactive_game_server':0,'active_sql_server':70,
                     'active_iis_server':70,'domain_controller':95,'active_file_server':80,