[3.6] bpo-34320: Fix dict(o) didn't copy order of dict subclass (GH-8624) (GH-9583)

When dict subclass overrides order (`__iter__()`, `keys()`, and `items()`), `dict(o)`
should use it instead of dict ordering.


https://bugs.python.org/issue34320
(cherry picked from commit 2aaf98c16ae3070378de523a173e29644037d8bd)


Co-authored-by: INADA Naoki <methane@users.noreply.github.com>


https://bugs.python.org/issue34320

1 files changed, 18 insertions, 0 deletions

diff --git a/Lib/test/test_call.py b/Lib/test/test_call.py
index 2e8819b..e71ede2 100644
--- a/Lib/test/test_call.py
+++ b/Lib/test/test_call.py
@@ -1,3 +1,4 @@
+import collections
 import datetime
 import unittest
 from test.support import cpython_only
@@ -6,6 +7,23 @@ try:
 except ImportError:
     _testcapi = None
 
+
+class FunctionCalls(unittest.TestCase):
+
+    def test_kwargs_order(self):
+        # bpo-34320:  **kwargs should preserve order of passed OrderedDict
+        od = collections.OrderedDict([('a', 1), ('b', 2)])
+        od.move_to_end('a')
+        expected = list(od.items())
+
+        def fn(**kw):
+            return kw
+
+        res = fn(**od)
+        self.assertIsInstance(res, dict)
+        self.assertEqual(list(res.items()), expected)
+
+
 # The test cases here cover several paths through the function calling
 # code.  They depend on the METH_XXX flag that is used to define a C
 # function, which can't be verified from Python.  If the METH_XXX decl