Merge branch '3.14' into backport-0953200-3.14

Author: brettcannon

.devcontainer/devcontainer.json

@@ -5,9 +5,6 @@
         "dnf",
         "install",
         "-y",
-        "which",
-        "zsh",
-        "fish",
         // For umask fix below.
         "/usr/bin/setfacl"
     ],

Doc/library/codecs.rst

@@ -1251,7 +1251,7 @@ particular, the following variants typically exist:
 +-----------------+--------------------------------+--------------------------------+
 | iso8859_3       | iso-8859-3, latin3, L3         | Esperanto, Maltese             |
 +-----------------+--------------------------------+--------------------------------+
-| iso8859_4       | iso-8859-4, latin4, L4         | Baltic languages               |
+| iso8859_4       | iso-8859-4, latin4, L4         | Northern Europe                |
 +-----------------+--------------------------------+--------------------------------+
 | iso8859_5       | iso-8859-5, cyrillic           | Belarusian, Bulgarian,         |
 |                 |                                | Macedonian, Russian, Serbian   |

Lib/_pyrepl/utils.py

@@ -264,6 +264,12 @@ def is_soft_keyword_used(*tokens: TI | None) -> bool:
             return True
         case (TI(string="case"), TI(string="_"), TI(string=":")):
             return True
+        case (
+            None | TI(T.NEWLINE) | TI(T.INDENT) | TI(T.DEDENT) | TI(string=":"),
+            TI(string="type"),
+            TI(T.NAME, string=s)
+        ):
+            return not keyword.iskeyword(s)
         case _:
             return False
 

Lib/multiprocessing/dummy/__init__.py

@@ -33,7 +33,7 @@
 
 class DummyProcess(threading.Thread):
 
-    def __init__(self, group=None, target=None, name=None, args=(), kwargs={}):
+    def __init__(self, group=None, target=None, name=None, args=(), kwargs=None):
         threading.Thread.__init__(self, group, target, name, args, kwargs)
         self._pid = None
         self._children = weakref.WeakKeyDictionary()

Lib/multiprocessing/forkserver.py

@@ -145,12 +145,13 @@ def ensure_running(self):
             cmd = ('from multiprocessing.forkserver import main; ' +
                    'main(%d, %d, %r, **%r)')
 
+            main_kws = {}
             if self._preload_modules:
-                desired_keys = {'main_path', 'sys_path'}
                 data = spawn.get_preparation_data('ignore')
-                main_kws = {x: y for x, y in data.items() if x in desired_keys}
-            else:
-                main_kws = {}
+                if 'sys_path' in data:
+                    main_kws['sys_path'] = data['sys_path']
+                if 'init_main_from_path' in data:
+                    main_kws['main_path'] = data['init_main_from_path']
 
             with socket.socket(socket.AF_UNIX) as listener:
                 address = connection.arbitrary_address('AF_UNIX')

Lib/multiprocessing/process.py

@@ -77,7 +77,7 @@ class BaseProcess(object):
     def _Popen(self):
         raise NotImplementedError
 
-    def __init__(self, group=None, target=None, name=None, args=(), kwargs={},
+    def __init__(self, group=None, target=None, name=None, args=(), kwargs=None,
                  *, daemon=None):
         assert group is None, 'group argument must be None for now'
         count = next(_process_counter)
@@ -89,7 +89,7 @@ def __init__(self, group=None, target=None, name=None, args=(), kwargs={},
         self._closed = False
         self._target = target
         self._args = tuple(args)
-        self._kwargs = dict(kwargs)
+        self._kwargs = dict(kwargs) if kwargs else {}
         self._name = name or type(self).__name__ + '-' + \
                      ':'.join(str(i) for i in self._identity)
         if daemon is not None:

Lib/test/_test_multiprocessing.py

@@ -5173,6 +5173,23 @@ def test_invalid_handles(self):
                           multiprocessing.connection.Connection, -1)
 
 
+#
+# Regression tests for BaseProcess kwargs handling
+#
+
+class TestBaseProcessKwargs(unittest.TestCase):
+    def test_default_kwargs_not_shared_between_instances(self):
+        # Creating multiple Process instances without passing kwargs
+        # must create independent empty dicts (no shared state).
+        p1 = multiprocessing.Process(target=lambda: None)
+        p2 = multiprocessing.Process(target=lambda: None)
+        self.assertIsInstance(p1._kwargs, dict)
+        self.assertIsInstance(p2._kwargs, dict)
+        self.assertIsNot(p1._kwargs, p2._kwargs)
+        # Mutating one should not affect the other
+        p1._kwargs['x'] = 1
+        self.assertNotIn('x', p2._kwargs)
+
 
 @hashlib_helper.requires_hashdigest('sha256')
 class OtherTest(unittest.TestCase):
@@ -6883,6 +6900,18 @@ def child():
         self.assertEqual(q.get_nowait(), "done")
         close_queue(q)
 
+    def test_preload_main(self):
+        # gh-126631: Check that __main__ can be pre-loaded
+        if multiprocessing.get_start_method() != "forkserver":
+            self.skipTest("forkserver specific test")
+
+        name = os.path.join(os.path.dirname(__file__), 'mp_preload_main.py')
+        _, out, err = test.support.script_helper.assert_python_ok(name)
+        self.assertEqual(err, b'')
+
+        # The trailing empty string comes from split() on output ending with \n
+        out = out.decode().split("\n")
+        self.assertEqual(out, ['__main__', '__mp_main__', 'f', 'f', ''])
 
 #
 # Mixins

Lib/test/mp_preload_main.py

@@ -0,0 +1,14 @@
+import multiprocessing
+
+print(f"{__name__}")
+
+def f():
+    print("f")
+
+if __name__ == "__main__":
+    ctx = multiprocessing.get_context("forkserver")
+    ctx.set_forkserver_preload(['__main__'])
+    for _ in range(2):
+        p = ctx.Process(target=f)
+        p.start()
+        p.join()

Lib/test/test_genericalias.py

@@ -402,7 +402,10 @@ def __deepcopy__(self, memo):
         aliases = [
             GenericAlias(list, T),
             GenericAlias(deque, T),
-            GenericAlias(X, T)
+            GenericAlias(X, T),
+            X[T],
+            list[T],
+            deque[T],
         ] + _UNPACKED_TUPLES
         for alias in aliases:
             with self.subTest(alias=alias):
@@ -432,10 +435,26 @@ def test_union_generic(self):
         self.assertEqual(a.__parameters__, (T,))
 
     def test_dir(self):
-        dir_of_gen_alias = set(dir(list[int]))
+        ga = list[int]
+        dir_of_gen_alias = set(dir(ga))
         self.assertTrue(dir_of_gen_alias.issuperset(dir(list)))
-        for generic_alias_property in ("__origin__", "__args__", "__parameters__"):
-            self.assertIn(generic_alias_property, dir_of_gen_alias)
+        for generic_alias_property in (
+            "__origin__", "__args__", "__parameters__",
+            "__unpacked__",
+        ):
+            with self.subTest(generic_alias_property=generic_alias_property):
+                self.assertIn(generic_alias_property, dir_of_gen_alias)
+        for blocked in (
+            "__bases__",
+            "__copy__",
+            "__deepcopy__",
+        ):
+            with self.subTest(blocked=blocked):
+                self.assertNotIn(blocked, dir_of_gen_alias)
+
+        for entry in dir_of_gen_alias:
+            with self.subTest(entry=entry):
+                getattr(ga, entry)  # must not raise `AttributeError`
 
     def test_weakref(self):
         for t in self.generic_types:

Lib/test/test_inspect/test_inspect.py

@@ -1755,14 +1755,55 @@ class C(metaclass=M):
 
 class TestFormatAnnotation(unittest.TestCase):
     def test_typing_replacement(self):
-        from test.typinganndata.ann_module9 import ann, ann1
+        from test.typinganndata.ann_module9 import A, ann, ann1
         self.assertEqual(inspect.formatannotation(ann), 'List[str] | int')
         self.assertEqual(inspect.formatannotation(ann1), 'List[testModule.typing.A] | int')
 
+        self.assertEqual(inspect.formatannotation(A, 'testModule.typing'), 'A')
+        self.assertEqual(inspect.formatannotation(A, 'other'), 'testModule.typing.A')
+        self.assertEqual(
+            inspect.formatannotation(ann1, 'testModule.typing'),
+            'List[testModule.typing.A] | int',
+        )
+
     def test_forwardref(self):
         fwdref = ForwardRef('fwdref')
         self.assertEqual(inspect.formatannotation(fwdref), 'fwdref')
 
+    def test_formatannotationrelativeto(self):
+        from test.typinganndata.ann_module9 import A, ann1
+
+        # Builtin types:
+        self.assertEqual(
+            inspect.formatannotationrelativeto(object)(type),
+            'type',
+        )
+
+        # Custom types:
+        self.assertEqual(
+            inspect.formatannotationrelativeto(None)(A),
+            'testModule.typing.A',
+        )
+
+        class B: ...
+        B.__module__ = 'testModule.typing'
+
+        self.assertEqual(
+            inspect.formatannotationrelativeto(B)(A),
+            'A',
+        )
+
+        self.assertEqual(
+            inspect.formatannotationrelativeto(object)(A),
+            'testModule.typing.A',
+        )
+
+        # Not an instance of "type":
+        self.assertEqual(
+            inspect.formatannotationrelativeto(A)(ann1),
+            'List[testModule.typing.A] | int',
+        )
+
 
 class TestIsMethodDescriptor(unittest.TestCase):