Restore backwards comapability

Tests fail locally even for master.  Does reverting to the previous
behaviour fix things?

master/buildbot/test/unit/test_util.py

@@ -236,12 +236,12 @@ def test_deep(self):
         self.assertEqual(util.flatten([[1, 2], 3, [[4]]]),
                          [1, 2, 3, 4])
 
-    def test_deeply_nested(self):
-        self.assertEqual(util.flatten([5, [6, (7, 8)]]),
-                         [5, 6, 7, 8])
+    # def test_deeply_nested(self):
+    #     self.assertEqual(util.flatten([5, [6, (7, 8)]]),
+    #                      [5, 6, 7, 8])
 
-    def test_tuples(self):
-        self.assertEqual(util.flatten([(1, 2), 3]), [1, 2, 3])
+    # def test_tuples(self):
+    #     self.assertEqual(util.flatten([(1, 2), 3]), [1, 2, 3])
 
     def test_dict(self):
         d = {'a': [5, 6, 7], 'b': [7, 8, 9]}

master/buildbot/util/__init__.py

@@ -66,7 +66,7 @@ def flattened_iterator(l, types=(list, tuple)):
             yield sub_element
 
 
-def flatten(l, types=(list, tuple)):
+def flatten(l, types=(list, )):
     """
     Given a list/tuple that potentially contains nested lists/tuples of arbitrary nesting,
     flatten into a single dimenstion.  In other words, turn [(5, 6, [8, 3]), 2, [2, 1, (3, 4)]]
@@ -76,6 +76,8 @@ def flatten(l, types=(list, tuple)):
     """
     # For backwards compatability, this returned a list, not an iterable.
     # Changing to return an iterable could break things.
+    if not isinstance(l, types):
+        return l
     return list(flattened_iterator(l, types))