Issue #892902: Added new tests for pickling recursive collections.

Lib/test/pickletester.py

@@ -103,6 +103,15 @@ class E(C):
 class H(object):
     pass
 
+# Hashable mutable key
+class K(object):
+    def __init__(self, value):
+        self.value = value
+
+    def __reduce__(self):
+        # Shouldn't support the recursion itself
+        return K, (self.value,)
+
 import __main__
 __main__.C = C
 C.__module__ = "__main__"
@@ -112,6 +121,8 @@ __main__.E = E
 E.__module__ = "__main__"
 __main__.H = H
 H.__module__ = "__main__"
+__main__.K = K
+K.__module__ = "__main__"
 
 class myint(int):
     def __init__(self, x):
@@ -1041,9 +1052,9 @@ class AbstractPickleTests(unittest.TestCase):
             x = self.loads(s)
             self.assertIsInstance(x, list)
             self.assertEqual(len(x), 1)
-            self.assertTrue(x is x[0])
+            self.assertIs(x[0], x)
 
-    def test_recursive_tuple(self):
+    def test_recursive_tuple_and_list(self):
         t = ([],)
         t[0].append(t)
         for proto in protocols:
@@ -1051,8 +1062,9 @@ class AbstractPickleTests(unittest.TestCase):
             x = self.loads(s)
             self.assertIsInstance(x, tuple)
             self.assertEqual(len(x), 1)
+            self.assertIsInstance(x[0], list)
             self.assertEqual(len(x[0]), 1)
-            self.assertTrue(x is x[0][0])
+            self.assertIs(x[0][0], x)
 
     def test_recursive_dict(self):
         d = {}
@@ -1062,29 +1074,63 @@ class AbstractPickleTests(unittest.TestCase):
             x = self.loads(s)
             self.assertIsInstance(x, dict)
             self.assertEqual(list(x.keys()), [1])
-            self.assertTrue(x[1] is x)
+            self.assertIs(x[1], x)
 
-    def test_recursive_set(self):
-        h = H()
-        y = set({h})
-        h.attr = y
+    def test_recursive_dict_key(self):
+        d = {}
+        k = K(d)
+        d[k] = 1
         for proto in protocols:
+            s = self.dumps(d, proto)
+            x = self.loads(s)
+            self.assertIsInstance(x, dict)
+            self.assertEqual(len(x.keys()), 1)
+            self.assertIsInstance(list(x.keys())[0], K)
+            self.assertIs(list(x.keys())[0].value, x)
+
+    def test_recursive_set(self):
+        y = set()
+        k = K(y)
+        y.add(k)
+        for proto in range(4, pickle.HIGHEST_PROTOCOL + 1):
             s = self.dumps(y, proto)
             x = self.loads(s)
             self.assertIsInstance(x, set)
-            self.assertIs(list(x)[0].attr, x)
             self.assertEqual(len(x), 1)
+            self.assertIsInstance(list(x)[0], K)
+            self.assertIs(list(x)[0].value, x)
 
-    def test_recursive_frozenset(self):
-        h = H()
-        y = frozenset({h})
-        h.attr = y
-        for proto in protocols:
+    def test_recursive_list_subclass(self):
+        y = MyList()
+        y.append(y)
+        for proto in range(2, pickle.HIGHEST_PROTOCOL + 1):
             s = self.dumps(y, proto)
             x = self.loads(s)
-            self.assertIsInstance(x, frozenset)
-            self.assertIs(list(x)[0].attr, x)
+            self.assertIsInstance(x, MyList)
             self.assertEqual(len(x), 1)
+            self.assertIs(x[0], x)
+
+    def test_recursive_dict_subclass(self):
+        d = MyDict()
+        d[1] = d
+        for proto in range(2, pickle.HIGHEST_PROTOCOL + 1):
+            s = self.dumps(d, proto)
+            x = self.loads(s)
+            self.assertIsInstance(x, MyDict)
+            self.assertEqual(list(x.keys()), [1])
+            self.assertIs(x[1], x)
+
+    def test_recursive_dict_subclass_key(self):
+        d = MyDict()
+        k = K(d)
+        d[k] = 1
+        for proto in range(2, pickle.HIGHEST_PROTOCOL + 1):
+            s = self.dumps(d, proto)
+            x = self.loads(s)
+            self.assertIsInstance(x, MyDict)
+            self.assertEqual(len(list(x.keys())), 1)
+            self.assertIsInstance(list(x.keys())[0], K)
+            self.assertIs(list(x.keys())[0].value, x)
 
     def test_recursive_inst(self):
         i = C()
@@ -1111,6 +1157,48 @@ class AbstractPickleTests(unittest.TestCase):
             self.assertEqual(list(x[0].attr.keys()), [1])
             self.assertTrue(x[0].attr[1] is x)
 
+    def check_recursive_collection_and_inst(self, factory):
+        h = H()
+        y = factory([h])
+        h.attr = y
+        for proto in protocols:
+            s = self.dumps(y, proto)
+            x = self.loads(s)
+            self.assertIsInstance(x, type(y))
+            self.assertEqual(len(x), 1)
+            self.assertIsInstance(list(x)[0], H)
+            self.assertIs(list(x)[0].attr, x)
+
+    def test_recursive_list_and_inst(self):
+        self.check_recursive_collection_and_inst(list)
+
+    def test_recursive_tuple_and_inst(self):
+        self.check_recursive_collection_and_inst(tuple)
+
+    def test_recursive_dict_and_inst(self):
+        self.check_recursive_collection_and_inst(dict.fromkeys)
+
+    def test_recursive_set_and_inst(self):
+        self.check_recursive_collection_and_inst(set)
+
+    def test_recursive_frozenset_and_inst(self):
+        self.check_recursive_collection_and_inst(frozenset)
+
+    def test_recursive_list_subclass_and_inst(self):
+        self.check_recursive_collection_and_inst(MyList)
+
+    def test_recursive_tuple_subclass_and_inst(self):
+        self.check_recursive_collection_and_inst(MyTuple)
+
+    def test_recursive_dict_subclass_and_inst(self):
+        self.check_recursive_collection_and_inst(MyDict.fromkeys)
+
+    def test_recursive_set_subclass_and_inst(self):
+        self.check_recursive_collection_and_inst(MySet)
+
+    def test_recursive_frozenset_subclass_and_inst(self):
+        self.check_recursive_collection_and_inst(MyFrozenSet)
+
     def test_unicode(self):
         endcases = ['', '<\\u>', '<\\\u1234>', '<\n>',
                     '<\\>', '<\\\U00012345>',