Fix GH Issue #3225 Flatten() doesn't handle dictionary views produces by py3 dict().{items(), values(), keys()}

2 files changed, 10 insertions, 4 deletions

diff --git a/src/engine/SCons/Util.py b/src/engine/SCons/Util.py
index b568ce5..6643b72 100644
--- a/src/engine/SCons/Util.py
+++ b/src/engine/SCons/Util.py
@@ -44,7 +44,7 @@ except ImportError:
     from UserString import UserString
 
 try:
-    from collections.abc import Iterable
+    from collections.abc import Iterable, MappingView
 except ImportError:
     from collections import Iterable
 
@@ -368,7 +368,13 @@ def print_tree(root, child_func, prune=0, showtags=0, margin=[0], visited=None):
 
 DictTypes = (dict, UserDict)
 ListTypes = (list, UserList)
-SequenceTypes = (list, tuple, UserList)
+
+try:
+    # Handle getting dictionary views.
+    SequenceTypes = (list, tuple, UserList, MappingView)
+except NameError:
+    SequenceTypes = (list, tuple, UserList)
+
 
 # Note that profiling data shows a speed-up when comparing
 # explicitly with str and unicode instead of simply comparing
diff --git a/src/engine/SCons/UtilTests.py b/src/engine/SCons/UtilTests.py
index 7ff509e..209c60f 100644
--- a/src/engine/SCons/UtilTests.py
+++ b/src/engine/SCons/UtilTests.py
@@ -875,13 +875,13 @@ class flattenTestCase(unittest.TestCase):
     def test_scalar(self):
         """Test flattening a scalar"""
         result = flatten('xyz')
-        assert result == ['xyz'], result
+        self.assertEqual(result,['xyz'], result)
 
     def test_dictionary_values(self):
         """Test flattening the dictionary values"""
         items = {"a": 1, "b": 2, "c": 3}
         result = flatten(items.values())
-        self.assertEquals(sorted(result),[1,2,3])
+        self.assertEqual(sorted(result),[1,2,3])
 
 
 if __name__ == "__main__":