[3.12] gh-110267: Add tests for pickling and copying PyStructSequence objects (GH-110272) (GH-110285)

(cherry picked from commit 2d4865d775123e8889c7a79fc49b4bf627176c4b)

Co-authored-by: Xuehai Pan <XuehaiPan@pku.edu.cn>

1 files changed, 73 insertions, 2 deletions

diff --git a/Lib/test/test_structseq.py b/Lib/test/test_structseq.py
index a9fe193..c6c0afa 100644
--- a/Lib/test/test_structseq.py
+++ b/Lib/test/test_structseq.py
@@ -1,4 +1,6 @@
+import copy
 import os
+import pickle
 import time
 import unittest
 
@@ -106,9 +108,78 @@ class StructSeqTest(unittest.TestCase):
 
         self.assertRaises(Exc, time.struct_time, C())
 
-    def test_reduce(self):
+    def test_pickling(self):
         t = time.gmtime()
-        x = t.__reduce__()
+        for proto in range(pickle.HIGHEST_PROTOCOL + 1):
+            p = pickle.dumps(t, proto)
+            t2 = pickle.loads(p)
+            self.assertEqual(t2.__class__, t.__class__)
+            self.assertEqual(t2, t)
+            self.assertEqual(t2.tm_year, t.tm_year)
+            self.assertEqual(t2.tm_zone, t.tm_zone)
+
+    def test_pickling_with_unnamed_fields(self):
+        assert os.stat_result.n_unnamed_fields > 0
+
+        r = os.stat_result(range(os.stat_result.n_sequence_fields),
+                           {'st_atime': 1.0, 'st_atime_ns': 2.0})
+        for proto in range(pickle.HIGHEST_PROTOCOL + 1):
+            p = pickle.dumps(r, proto)
+            r2 = pickle.loads(p)
+            self.assertEqual(r2.__class__, r.__class__)
+            self.assertEqual(r2, r)
+            self.assertEqual(r2.st_mode, r.st_mode)
+            self.assertEqual(r2.st_atime, r.st_atime)
+            self.assertEqual(r2.st_atime_ns, r.st_atime_ns)
+
+    def test_copying(self):
+        n_fields = time.struct_time.n_fields
+        t = time.struct_time([[i] for i in range(n_fields)])
+
+        t2 = copy.copy(t)
+        self.assertEqual(t2.__class__, t.__class__)
+        self.assertEqual(t2, t)
+        self.assertEqual(t2.tm_year, t.tm_year)
+        self.assertEqual(t2.tm_zone, t.tm_zone)
+        self.assertIs(t2[0], t[0])
+        self.assertIs(t2.tm_year, t.tm_year)
+
+        t3 = copy.deepcopy(t)
+        self.assertEqual(t3.__class__, t.__class__)
+        self.assertEqual(t3, t)
+        self.assertEqual(t3.tm_year, t.tm_year)
+        self.assertEqual(t3.tm_zone, t.tm_zone)
+        self.assertIsNot(t3[0], t[0])
+        self.assertIsNot(t3.tm_year, t.tm_year)
+
+    def test_copying_with_unnamed_fields(self):
+        assert os.stat_result.n_unnamed_fields > 0
+
+        n_sequence_fields = os.stat_result.n_sequence_fields
+        r = os.stat_result([[i] for i in range(n_sequence_fields)],
+                           {'st_atime': [1.0], 'st_atime_ns': [2.0]})
+
+        r2 = copy.copy(r)
+        self.assertEqual(r2.__class__, r.__class__)
+        self.assertEqual(r2, r)
+        self.assertEqual(r2.st_mode, r.st_mode)
+        self.assertEqual(r2.st_atime, r.st_atime)
+        self.assertEqual(r2.st_atime_ns, r.st_atime_ns)
+        self.assertIs(r2[0], r[0])
+        self.assertIs(r2.st_mode, r.st_mode)
+        self.assertIs(r2.st_atime, r.st_atime)
+        self.assertIs(r2.st_atime_ns, r.st_atime_ns)
+
+        r3 = copy.deepcopy(r)
+        self.assertEqual(r3.__class__, r.__class__)
+        self.assertEqual(r3, r)
+        self.assertEqual(r3.st_mode, r.st_mode)
+        self.assertEqual(r3.st_atime, r.st_atime)
+        self.assertEqual(r3.st_atime_ns, r.st_atime_ns)
+        self.assertIsNot(r3[0], r[0])
+        self.assertIsNot(r3.st_mode, r.st_mode)
+        self.assertIsNot(r3.st_atime, r.st_atime)
+        self.assertIsNot(r3.st_atime_ns, r.st_atime_ns)
 
     def test_extended_getslice(self):
         # Test extended slicing by comparing with list slicing.