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


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>
diff --git a/Lib/test/test_builtin.py b/Lib/test/test_builtin.py
index 8f91bc9..e7202cd 100644
--- a/Lib/test/test_builtin.py
+++ b/Lib/test/test_builtin.py
@@ -1961,6 +1961,15 @@
         with self.assertRaises(TypeError):
             type('A', (B,), {'__slots__': '__weakref__'})
 
+    def test_namespace_order(self):
+        # bpo-34320: namespace should preserve order
+        od = collections.OrderedDict([('a', 1), ('b', 2)])
+        od.move_to_end('a')
+        expected = list(od.items())
+
+        C = type('C', (), od)
+        self.assertEqual(list(C.__dict__.items())[:2], [('b', 2), ('a', 1)])
+
 
 def load_tests(loader, tests, pattern):
     from doctest import DocTestSuite
diff --git a/Lib/test/test_call.py b/Lib/test/test_call.py
index 3f9987c..362c31c 100644
--- a/Lib/test/test_call.py
+++ b/Lib/test/test_call.py
@@ -9,6 +9,23 @@
 import collections
 import itertools
 
+
+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
diff --git a/Lib/test/test_dict.py b/Lib/test/test_dict.py
index 38521bb..90c0a31 100644
--- a/Lib/test/test_dict.py
+++ b/Lib/test/test_dict.py
@@ -1222,6 +1222,36 @@
 
         self.assertRaises(RuntimeError, iter_and_mutate)
 
+    def test_dict_copy_order(self):
+        # bpo-34320
+        od = collections.OrderedDict([('a', 1), ('b', 2)])
+        od.move_to_end('a')
+        expected = list(od.items())
+
+        copy = dict(od)
+        self.assertEqual(list(copy.items()), expected)
+
+        # dict subclass doesn't override __iter__
+        class CustomDict(dict):
+            pass
+
+        pairs = [('a', 1), ('b', 2), ('c', 3)]
+
+        d = CustomDict(pairs)
+        self.assertEqual(pairs, list(dict(d).items()))
+
+        class CustomReversedDict(dict):
+            def keys(self):
+                return reversed(list(dict.keys(self)))
+
+            __iter__ = keys
+
+            def items(self):
+                return reversed(dict.items(self))
+
+        d = CustomReversedDict(pairs)
+        self.assertEqual(pairs[::-1], list(dict(d).items()))
+
 
 class CAPITest(unittest.TestCase):